Strength & Conditioning Coach  (see bio below) was kind enough to send me his noted pertaining to the research associated with warm-ups. Hopefully this information will be valuable to other strength and sport coaches.

Synopsis and Findings of Study-

• By  David G. Behm and Anis Chaouachi at School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John’s, NF A1C 5S7, Canada and Tunisian Research Laboratory ‘‘Sport Performance Optimisation’’, National Center of Medicine and Science in Sports, Tunis, Tunisia
• Published Eur J Appl Physiol (2011) 111:2633–2651 DOI 10.1007/s00421-011-1879-2
• This is a review of the effects of static and dynamic stretching on performance
• ASAP, ProQuest 5000, MEDLINE, SPORT Discus, AUSPORT, ScienceDirect, Web of Science and Google Scholar databases were searched
• Although it seems more likely from the literature that static stretching decreases performance while dynamic stretching may increase performance, there is a discrepancy in the literature that static stretching does actually decrease performance.
• The negative effects of static stretching may be due to duration and type of contraction there are also mixed findings with this.
• Because static stretching can increase muscle compliance, it can enhance the ability of the MTU to store elastic energy over a longer period. “Some studies using longer duration contractions or slower stretch-shortening  cycle activities have shown either no effect or increased performance following stretching. So bench press actions with a long eccentric contraction and longer distance running as well as longer ground contact of transition times may benefit from a more compliant and flexible MTU
• Walshe and Wilson showed that drop jumps were impaired by stiffer MTU because of the decreased ability to “mitigate the high loads” which increases inhibition via Golgi tendon organs. It overrides stretch reflex an instead results in protective mechanism.
• While not all actions benefit from this, those with prolonged SSC might.
• Conversely, elite sprinters have been shown to have negative effects of changes in viscoelastic properties and stiffness of MTU leading to negatively impact transmission of force and rate of force transmission. Stiffer MTU may augment these factors by improving force-velocity and length-tension relationship.

Synopsis and Findings of Study-

• By Felipe L.P. CARVALHO, MAURO C.G.A. CARVALHO, ROBERTO SIMAO, THIAGO GOMES M., B. PABLO COSTA, LUDGERO B. NETO, L.P. RODRIGO CARVALHO, AND THIS LIO H. M. DANTAS
• Published September 2012 in the Journal Of Strength and Conditioning Research (www.nsca.com) Volume 26 |Number 9|pages 2447-2452 in September 2012
• The purpose of this study was to see the immediate effects of 3 different stretching methods that were combined with a specific warm-up protocol. These were tested to see the effect on vertical jump performance
• Participants included 16 young male tennis players 14.5 ± 2.8 years, 175 ± 5.6 cm (appx. 5’7” ± 2.2 inches) , 64 ± 11.1 Kg ( appx. 141 lbs ± 24 lbs). They were physically activated, had no limitations, and had greater than 2 years experience in their sport.
• There were 4 different experimental conditions on 5 successive days. The athletes were randomly assigned to the 4 different conditions. Every session had both a general and specific warm up, included 5 minutes of running followed by 10 jumps and one of the 4  experimental conditions
• The participants performed 1 of 4 conditions randomly on 4 consecutive days  always at 3pm 2 hours after having lunch and then performed 3 squat jumps and 3 countermovement jumps. The jumps were measured electronically. The athletes came in 5 times but the first day was to read and sign informed consent, explanation of protocol, and anthropometric measurements.
• Every athlete went through the same warm-up protocol of 5 minutes running around a tennis court with a standardized HR or appx. 140 b .min. followed by 5 squat jumps and 5 countermovement jumps. After this they performed one of the 4 conditions:
• The 4 conditions were:

1)      The Control Condition (CC) – 5 minutes of passive rest without stretching exercises

2)       Passive Stretching Condition (PSC) – 5 minutes of passive static stretching ( 3 exercises, 3 sets, 15 seconds)

3)      Active Stretching Condition (ASC) – 5 minutes of active static stretching (3 exercises, 3 sets, 15 seconds).

4)      Dynamic Stretching Condition (DC) –  5 minutes of dynamic stretching (3 exercises, 3 sets,).

• All stretching exercises focused on the hamstrings, quadriceps, and triceps surae muscles to replicate common stretching routines before sports activities. All stretching, except the dynamic, was held for 15 seconds and the static stretches (both active and passive) were held at a point of mild discomfort.  They dynamic stretches were to be performed with a bob in 1:1- second cycles for 30 seconds trying to stretch further every time.
• After each of the 4 conditions the athletes performed 3 more squat jumps and 3 more countermovement jumps to test the effect of each protocol.
• Their jump height was measured by a software called the Axon Jump 4.0 and the athletes were told by the investigator when to jump as high as they could on this mat.

Background-

• Although there has been a common belief in the past that stretching exercises in warm-up reduces DOMS and chance of injury, recent studies have shown that stretching exercises decrease strength and power output and some authors have advised against it for predominantly strength and power activities.
• Behm and Chaouachi  (Behm, DG and Chaouachi, A. A review of the acute effects of static and dynamic stretching on performance. Eur J Appl Physiol 111:1–19, 2011) found that dynamic stretching is more helpful than static to improve explosive performance.
• Dynamic stretching has been shown to improve performance though enhancing MU excitability as well as greater central activations of motor neuron, increased MU recruitment and synchronization, and decreased presynaptic inhibition.
• The decrease in performance caused by static stretching involves both mechanical (“mechanical stretching results in a longer and more compliant musculo-tendonous unit, resulting in reduced peak torque and slower RFD.”) and neural (decreased MU activation) factors.
• Other studies have shown conflicting results of effect of static, ballistic, and dynamic stretching

Considerations and Conclusions-

• For squat jumps – performance decreased with PSC (passive stretching) and ASC (active stretching) when compared to the CC (control condition). PSC jumps being 28.7 ± 4.3 cm; p= 0.01 while ASC jumps being 28.7 ± 4.7 cm and PSC jumps being – 28.7 ± 4.3 cm; p= 0.02 on average.
• For counter movement jumps (CMJs) – no significant performance decreases occurred with any of the 4 conditions (p > 0.05) compared with the CC.
• There was a significant increase in squat jump performance when comparing Dynamic stretching condition (29.6 ± 4.9 cm; p=0.02) with PSC (28.7 ± 4.3 cm)
• There was more of a significant increase in performance in counter movement jumps when performing (ASC) active stretching (34.0 ± 6.0 cm; p=0.04) and even more with (DC) dynamic
• Participants used warm-ups with activities using jumps and the authors noted that this could have influenced outcomes.
•  This shows that dynamic stretching is best for  a warm-up in young athletes
• Although squat jumps performance suffered after the use of passive and active static stretching as compared with the CC, no decrease in counter movement jump performance was observed. The authors explain that this MAY be because the volume of stretching was not high enough to change musculotendinous stiffness and so not altering “rate of muscle activation and reflex sensitivity. This idea is corroborated with another study by Yamaguchi and Ishii which showed that 30 second static stretching for lower body muscle groups did not show decreased ability to generate power in the lower body. The authors also suggest that the loss in power output of subsequent activity maybe dependent on the intensity and volume of stretching.

Synopsis and Findings of Study-

• By AVERY D. FAIGENBAUM,  MARIO BELLUCCI,  ANGELO BERNIERI,  BART BAKKER, AND KARLYN HOORENS at (Department of Health and Exercise Science, The College of New Jersey, Ewing, New Jersey 08628; 2Regional Institute of Educational Research, Rome, Italy; 3Rome International School, Rome, Italy
• Published 2005 in the Journal of Strength and Conditioning research 19(2), 376–381 (volume 19 number 2 pages 376-381).
• 60 children, 27 girls and 33 boys (mean age 11.3 ± 0.7 years, mean height of 147.1 ± 8.9 cm and mean weight of 39.2 ± 7.7 kg) performed 3 different warm-up routines on nonconsecutive days to compare the acute effects on youth fitness. The routines were done in random order.
• After each warm-up session (each lasting 10 minutes), the subjects tested vertical jump, long jump, shuttle run, and v-sit flexibility.
• The 3 different warm-up routines were:

1)Protocol A – 5 minutes of walking and 5 minutes of static stretching (SS) – 6 stretches in all held for 15 seconds each. They resembled a typical warm-up routine stretch used and recommended for PE

2) Protocol B  – 10 minutes of dynamic exercise (DY) progressing form moderate to high intensity. Each exercise was done for a distance of 13m, rested about 10 seconds and repeated the same distance back to the starting point. It was to replicate warm-up routines done for sports. (High knee walk, straight leg march, hand walk, lunge walks, backward lunge, high knee skip, lateral shuffle, back pedal, heel ups, high knee run

3) Protocol C -10 minutes of dynamic exercise (same as in protocol B)AND 3 drop jumps performed 1 minute after dynamic warm up from 15-cm boxes (DYJ). Subjects jumped down from first box landed with both feet and jumped right onto second box of equal height placed 80 cm away. They were to minimize ground reaction time and the drop jumps were used because “the primary muscles controlling movements requiring stretch-shortening muscle actions become highly activated during the eccentric phase.”

Background-

• Static stretching has long been a pre-performance procedure for both young and old even though there is little research to back the idea that it can prevent injury and increase performance. In fact, recent studies have shown acute bouts of static stretching can negatively affect subsequent strength or power performance in adults.

Significant Methods-

• All participants had 2 intro sessions to familiarize them with fitness tests and warm up protocols to reduce influence of “learning effects.”
• The warm up sessions were conducted in groups of 15-20 and supervised by 2 Physical Education Teachers in a school gym (the same teacher tested the same subjects every time) and the three protocols were done in random order and administered 2 to 4 days apart.
• The participants were not to do any moderate to vigorous activity.
• The fitness tests that were conducted after  warm-up protocols (standing long jump, vertical jump, and shuttle run tests were standardized and performed with a countermovement to initiate for both the vertical and horizontal jumps.
• The best of 3 jumps was recorded  a measured to the nearest 0.5 cm and the best of 2 shuttle runs was recorded to nearest 0.1 second. This was timed with a handheld stopwatch. The v-sit flexibility test was to judge lower back and hamstring flexibility and the best of 3 trials was  recorded to nearest 0.5 cm.
• “Test-retest reliability intra-class R for the dependent variables was R > 0.85
• All subjects walked at easy pace for 2 minutes after warm-up protocol prior to testing. The tests were done in the following order – vertical jump, long jump, shuttle run, and flexibility. All subjects completed these test in about 25-30 minutes and done within 9 days.

Considerations and Conclusions-

• There was no significant increase in flexibility with any of the 3 warm up routines.
• Vertical Jump and shuttle-run performance was significantly impaired following static stretching as compared with both dynamic exercise routine (DY) and dynamic exercise plus 3 box jumps routine (DYJ) and long jump performance was significantly impaired following static stretching as compared with DYJ
• Most of the subjects (77%) participated in  after school sport activities (mostly soccer and swimming) at least 3 days a week.
• There was a secondary test to assess cardiorespiratory demand of the 3 protocols. Eleven randomly selected subjects (7 boys and 4 girls) had HR monitors on that interfaced with a computer and recorded HR date every 5 seconds for statistical analysis.
• The findings were consistent with studies by Young and Elliot and McNeal and Sands that both observed decreased jumping performance after static stretching.
• The most noticeable decrease in vertical jump performance (lowered by 6.5%)was after low intensity aerobic exercise and static stretching. Long jump and shuttle-run speed was reduced by 1.9% and 2.6%.
• The author admits that the time in between the warm-up protocols and the testing may have influenced results and that the first test may have influenced performance of subsequent tests.
• Decreasing musculotendinous stiffness through stretching “may place the contractile elements in a position that is less than optimal for generating force rapidly.”
• Study shows that 10 minutes of moderate to high intensity dynamic exercise can positively influence power performance in children by enhancing neuromuscular function because of something referred to as postactivation potentiation (PAP) – which is believed to improve speed and power performance by increase rate of force development.

Synopsis and Findings of Study-

• By ARNE G. THOMPSEN, TED KACKLEY, MELINDA A. PALUMBO, AND AVERY D. FAIGENBAUM
• Published 2007 in the Journal Of Strength and Conditioning Research Volume 21 |Number 1|pages 52-56 (Department of Exercise Science and Physical Education, University of Massachusetts, Boston, Massachusetts 02125; 2Department of Health and Exercise Science, The College of New Jersey, Ewing, New Jersey 08628.)
• The purpose of the study was to see immediate effects of 3 different warm-up protocols on vertical jump and long jump performance with and without a weighted vest.
• Participants included 16 division III college athlete women with at least 1 year of resistance training experience(primarily ages 18-24 (age 19.7 ± 1.4 years, weight – 67.0 ± 10.7 kg, height- 165.7 ± 11.4 cm).
• When study began, the athletes were in the midst of a preseason strength and conditioning program including plyos, weightlifting and strength exercises including the bench press and squat.
• For this study, they performed 3 test sessions in random order on 3 nonconsecutive days. Before the tests they performed 1 of 4 warm up protocols, each lasting 10 minutes.
• The protocols were as follows:

1)      Low to moderate intensity stationary cycling for five minutes followed by 4 lower body static stretches (rating of 3 or 4 on the modified Borg rating of perceived exertion scale (3 sets for 20 seconds). (SS) an aerobic warm up was used first because it was thought inappropriate to do static stretching in a rested state.

2)      12 moderate to high intensity dynamic exercises(DY) (11 different exercises, with 1 exercise [lateral lunge] being performed twice) that progressed from moderate-to high-intensity movements (Table 2). Subjects performed each dynamic exercise for 20 yd, rested for about 5–10 seconds, and then repeated the same exercise for 20 yd as they returned to the starting point.

3)      The same 12 dynamic exercises with weighted vest weighing 10% of bodymass (around 6-7kg). The weighted vest was only used on the last 4 exercises though. (DYV). Same exercise as above for DY but added a weighted vest for last 4 (high knee skip, high knee run, heel kick, power skip).

• Vertical jump performance increased following DYV (p < 0.05) (43.9 ± 6.7 cm) and DY (43.6 ± 6.5 cm) as compared to SS (41.7 ± 6.0 cm).
• Long jump performance was significantly better (p< 0.05) following DYV (186.8 ± 19.5 cm) compared with DY measurements (182.2 ± 19.1 cm) which in turn was significantly greater (p < 0.05) than performance following SS (177.2± 18.8 cm).

Considerations and Conclusions-

• Both long jump and vertical jump performance was better after dynamic warm up both weighted and not weighted.
• Long jump was significantly better with a dynamic warm up including the weighted vest as opposed to the same dynamic warm up without a weighted vest. But dynamic warm up without a weighted vest was still much better than stationary cycling and static stretching warm up
• This was the first test to study immediate results of jump performance using dynamic warm up with a vest compared to without in athletic women.
• Long jump performance was 2.5% better with a weighted vest than without
• Although the authors cite studies that agree with findings, a study by Koch et al. shows no significant effect of any warm up routine on jump performance. But differences in training age, intensity and duration may account for this.
• Weighted vests may enhance neuromuscular function because of PAP in type 11 fibers but it must be noted that excessive weight and volume may not produce these same results.
• YOUNG, W., A. JENNER, AND K. GRIFFITHS. Acute enhancement of power performance from heavy load squats. J. Strength Cond. Res. 12:82–84. 1998. –  Found similar results in that counter movement jump height increased 3.3% after 1 set of half squats with a 5 rep max load.

Synopsis and Findings of Study-

• By DUANE KNUDSON, KATI BENNETT, ROD CORN, DAVID LEICK, AND
• CHRIS SMITH at Department of PE and ES, California State University, Chico Chico, California 95929
• Published 2001 in the Journal of Strength and Conditioning research 15(1), 98–101
• A sample of 20 young adults (10 males and 10 females mean age of 23.7 ± 4.5 years, mean heights and weights of males – 1.76 (0.04) m, 85.7 (9.7) kg, mean heights and weights of females 1.64 (0.05) m, 62.4 (5.2) kg) were tested on 2  occasions with a random warm-pup routine to find acute effect of stretching on kinematics of vertical jump using saggital plane videography (60 Hz)
• The goal of the study was to see the acute changes in kinematic variables related to stretch-shortening cycle (SSC) muscle actions from stretching during warm-up. It focuses on a good pool of physically active adults rather than specific athletes, although some athletes of various sports were uses.

Significant Methods –

• The study included 2 test sessions scheduled a week at a similar time of day apart with 2 warm up routines – control ( C ) and stretching (S)
• The routines bean with taping of 13 mm diameter  retroflective marks to the fifth metatarsal, lateral malleolus, lateral epicondyle of the femur, greater trochanter, and acromion process.
• After, subjects rode a lifecycle at resistance setting  1 (80rpm) for 3 minutes and then performed 3 practice vertical jumps. For the control routine, the subjects sat and rested 10 minutes after the bike and then performed  the jumps but for the stretching group subjects performed 3 sets of stretching, each stretch held for 3 15 second repetitions. This lasted 10 minutes as well.
• The stretches are as follows: seated bilateral hamstring stretch, standing unilateral quadriceps stretches, and standing unilateral calf stretches. Quadricep and calf stretches were performed one leg at a time. All stretching was supervised by a certified athletic trainer and were held at a point just before discomfort.
• Videotapes of jumps were digitized from 5 frames before the countermovement to 5 frames after take-off with the “Peak Motus 4.3 videography system. The kinematic data was smoothed with a digital filter with optimal cutoff frequencies. The kinematics of a 4 segment rigid body model was calculated, and athropometric date was used to calculate the whole body COG.

Considerations and Conclusions – 

• There was an overall nonsignificant effect of stretching on mean change of peak vertical velocity 

Acute effects of two different warm-up protocols on flexibility and lower limb explosive performance in male and female high level athletes

Synopsis and Findings of Study-

• By Charilaos Tsolakis and Gregory C. Bogdanis at Department of Physical Education and Sport Science, University of Athens, Greece
• Published (online) December 2012 in the Journal Of Sports Science and Medicine (Volume 11 |pages  669-675
• The study took 20 high level speed/power athletes athletes/international level fencers who were members of the National team with considerable experience (10 males and 10 females)
• The athletes performed conditioning to improve aerobic and anaerobic function twice a week and alternated weight training, circuit training, sprint and plyo drills.
• The athletes were to perform two different warm-up protocols paired with either a moderate or high volume of ply jumps to see effects of lower limb power and flexibility were effected.
• Each athlete came in 3 times. The first was the familiarize and take anthropometric measurements as well as go over procedures and the second two times were testing sessions done at the same time each day (16:00-20:00pm) with 2-4 days in between.
• The warm up protocols both began with 5 min. light jogging.
• The two protocols were:

1)short static stretching (15 seconds long) of main muscle groups (quads, hamstrings, and triceps surae)

2) Long static stretching (45 seconds long) of same muscle groups.

• The testing that followed included one of the following either 3 sets of 3 (short stretching treatment) or 3 sets of 5 tuck jumps for (long stretching treatment).
• Hip joint flexion was measured with a Lafayette goniometer before and after 5 min. warm up, after stretching and 8 minutes after tuck jumps.
• Counter movement jump performance was also evaluated by an Ergojump contact platform before and after stretching treatment as well as both immediately after and 8 minutes after tuck jumps.
• Condition time and gender were all compared through ANOVA
• Women had greater ROM than men at baseline (125 ± 8 degrees vs. 94 ± 4 degrees p < 0.001) but the pattern of change in hip flexibility was the same between the genders.
• Counter movement jump (CMJ) performance was better in males at baseline (38.2 ± 1.9 cm vs. 29.8 ± 1.2 cm p < 0.01) but the pattern of change was the same between genders as well.
• Flexibility increased by 6.8 ± 1.1% ( p <0.01) after the warm-up and increased another 5.8 ± 1.6% (p < 0.01) after stretching. This flexibility remained increased 8 min. after the tuck jumps
• The short stretching protocol did not affect CMJ performance  but was negatively effected by the long stretching protocol with a 5.5 ± 0.9% (p<0.01) decrease in performance.
• However, 8 min. after the tuck jumps were done, CMJ performance was returned to baseline performance (baseline value – p =0.075) which indicates that although lower body power is decreased by long bouts of stretching, performing explosive exercises may reverse this.

Background-

• Performing dynamic general or specific explosive movements that mimic sport and increase muscle temperature using maximal or near maximal muscle actions can induce a phenomenon called post-activation potentiation (PAP) which enhances muscle power in following 3-20 minutes as found in Gelen, 2010; Hilficker et al., 2007; Hodgson et al., 2005; Kilduff et al., 2007).
• This study was to examine combined effect of stretching and muscle potentiating exercises used in speed/power sport warm-up on lower body power and flexibility – something that had not been combined in study and examined in detail. Long and short stretching protocols was also focused on to study to see if they would have differing outcomes.

Significant Methods-

• Flexibility measurements were taken first, then 5 min. of light jogging followed by a bas;line measurement of CMJ and another measurement of hip ROM.
• Stretching either for 15 s or 45 s to the point of discomfort. Static stretching included three different stretching exercises – unilateral standing quadriceps stretch, unilateral standing hamstring stretch, and unilateral standing calf stretch for each leg.
• Two minutes after static stretching CMJ and ROM were checked on dominant leg again.
• 3×5 of tuck jumps (PAP intervention) were done after the long stretching protocol and 3×3 tuck jumps were done after the short stretching protocol. Both rested 60 seconds between sets
• Immediately after this and after 8 minutes of recovery CMJ was measured again and ROM was measured again as well but only after 8 minutes of recovery.

Considerations and Conclusions –

• There was no significant correlation between changes in ROM and CMJ at any point
• Although both long and short stretching protocols increase hip flexion ROM the same (~12.6%) CMJ performance was reduced only after longer duration static stretching about 5.5% This reduction continued when tested right after the tuck jumps but then performance returned to baseline when test 8 min. after tuck jumps.
• The authors make the point that because performance did not increase significantly but rather remained the same after the tuck jumps (PAP) may indicate that although the short stretching did impair performance, the PAP returned performance to baseline- they basically cancelled themselves out.
• Although the argument can be made that the long stretching protocol caused decreased performance because of the increase in ROM, the short stretching protocol caused similar increases which indicates that the decreased performance in CMJ after the long stretching protocol was a neural issue (reduction of excitatory drive from Ia afferents onto the alpha motorneuron which is, in turn caused by a decreased resting discharge of muscle spindles.

Synopsis and Findings of Study-

• By Justin R. Murphy, Mario C. Di Santo, Thamir Alkanani, and David G. Behm at School of Human Kinetics and Recreation, Memorial University of Newfoundland
• Published Appl. Physiol. Nutr. Metab. 35: 679-690 (2010)
• This study tested whether ROM could be improved with a short duration and volume of static stretching done during warm-up without negatively effecting performance.
• It involved  eleven male volunteers ages 22-30 yrs. The average height was 182.1 ± 8.26 cm, average weight 84.6 ± 9.03 kg. They weight trained for competitive sports.
• The subjects underwent two experimental protocols including ROM and performance measures.
• The ROM protocol involved 3 conditions: 1) SS – 6 reps of 6 s hip extensor passive stretches 2) AS – 10 min treadmill run prior to SS 3)ASA – 5 minutes of treadmill running prior to and following the stretching routine. The subjects completed all 3 conditions in random order on nonconsecutive days.
• Pre and post intervention changes in hip flexion passive ROM, passive hip flexion ROM were  taken 1, 10, 20, and 30 min. intervals after the warm-up condition.
• The performance protocol involved 4 conditions: there were 6 reps each of 6 s passive stretches for hip extensors, quadriceps and plantar flexors. The AS and ASA conditions employed the same aerobic activity as the ROM protocol.
• The control condition for the performance protocol involved a 10 min treadmill run without a stretching routine.
• The performance protocol measured pre- and post intervention changes to countermovement jump height balance contacts, balance ration, reaction time and movement time.

Considerations and Conclusions-

• The ASA produced greater ROM overall than the SS and AS conditions persisting for 30 min.
• There was no  changes in passive muscle tension or EMG
• For performance protocol – there was no main effects of condition but main effect for time with countermovement jump height being greater at 1 and 10 min post warm up
• Balance rations and MT improved at 10 min post warm up.

Controlled Warm-Up Intensity Enhances Hip Range Of Motion

Synopsis and Findings of Study-

• By David L. Wenos and Jeff G. Konin at Department of Health Sciences, Human Performance Laboratory, James Madison University, Harrisonburg,Virginia 22807
• Published 2004 in the Journal Of Strength and Conditioning Research Volume 18 |Number 3| pages  529-533 18(3), 529–533
• The study took 12 active and injury free men (mean age 25.6 ± 4.2 years, mean height 172.2 ± 9.7, mean weight ±72.2 ± 9.7 kg) and had them perform two active warm-up treatments and one passive warm- up treatment at the same time each day ± 2 hours . All treatments were administered 24 hours apart from each other. They were randomly assigned to see increase in temperature in hamstrings of dominant leg.
• For the active treatments, the subjects ran on treadmill at 0% grade and a self-selected running speed was used for both treatments. The active treatments were as follows:

1)RER or 1.00 was reached as measured by a Quniton metabolic cart, participants continued to run for additional 3 minutes to maintain this RER. “The respiratory exchange ratio (RER) of the volume of carbon dioxide produced divided by oxygen consumption represents whole-body metabolic activity. For this study, an RER ratio of 1.0 was selected. It represents short-term, moderate to heavy submaximal exercise where carbohydrates are the primary energy substrate. For an RER of 1.0, oxygen consumption is characterized by an initial rise and plateaus to a steady state. This is comparable with warming up until sufficient body heat produces a sweat”

2) 60% of HRR was achieved through same treadmill procedures

• The passive treatment involved placing pads (that were housed in a hydrocollator heating unit at 76.6 degrees Celsius for minimum of 6 hours) wrapped in a towel over the hamstring area.
• Timed PNF (hold relax) was done immediately after each treatment laying in supine position with other leg secured to table. PNF was maintained for 10 seconds and repeated 3 times.
• Hip flexion ROM was measured immediately after PNF and also 5, 10 and 15 minutes after with a Leighton Flexometer .
• RPE was taken during this.
• EMG activity of biceps femoris was measured during PNF

• Tukey tests (p , 0.05) showed ROM for RER (107.48) was greater than all other treatments. ROM for HRR (102.88) and HP (103.48) did not differ from each other but were greater than the control (98.88). Ratings of perceived exertion were lowest for RER (4.0) and highest for control (8.5). Ratings of perceived exertion for HRR (6.0) and HP (6.5) were similar.

Background-

• Flexibility is considered 1 of 5 health related components of fitness sand defined as complete ROM about a joint.
• It has been hypothesized that a depression of the Hoffman reflex after a voluntary contraction is the mechanism that makes PNF (the most widely supported means to increase flexibility) increase ROM.
• Worrell et al. found that increasing hamstring flexibility also increased ability to produce force using selective isokinetic paramaters.
• Other studies do not seem to indicates greatly that applying heating or cooling agents to muscle produces greater flexibility even when combined with other methods.

Synopsis and Findings of Study-

• By Christian Cook, Danny Holdcroft, Scott Drawer, and Liam P. Kilduff at College of Engineering  Swansea University Singleton Park Wales
• Published ahead of time 2012 in International Journal of Sports  Physiology and Performance
• This study was to see effects of varying  warm-ups on British Bob skeleton athletes as opposed to their typical warm-up (warming up 30 minutes before racing).
• The study included three female and three male British skeleton athletes  who were competing for election to Olympic team.
• Male athletes (mean±SD) at time of study were: 1.74±0.08m tall; 78.7±10.2kg heavy and aged 28.3±3.1y, while female athletes were: 1.72±0.02 tall; 62.0±1.6kg heavy and 27.3±0.5y old.
• Each warm-up was repeated twice two days apart at the same time each time – 9am and were randomized in a “counterbalanced manner.”
• Each test was repeated twice at room temperature (~20.0 °C, 70-75% humidity) , each two days apart giving a total of 6 trials per protocol per athlete.
• The warm up protocols were as follows:

1)      Protocol 1 (P1) – was the standardized warm-up that the athletes normally did (this was the control) and lasted 20 min. It was done 35 min. before testing – in accordance to how the athlete would normally warm-up. The athletes performed 3 x 20 m jogging and skipping with walking back; 3 x 20m at submaximal sprinting, 3 x 20 m sprint form drills, 2 z 20m leg swings; fast feet and high knees, 3 x 10m maximal sprints, 30s mixed calisthenics (press-ups; dead bugs; planks) and 2 min of dynamic stretching

2)      Protocol 2 (P2) – used the same time and durations but increased intensity by including more sprints and sprint drills and reducing rest intervals. The meters covered was increased by appx. 30%. This was complete the same time before testing

3)      Protocol 3 (P3) – used the same high intensity as P2 but was completed 15 min before testing instead.

4)      Protocol 4 (P4) – used the same high intensity warm-up but split into two 10 minute warm-ups. The first was done 40 min. before testing and second 15 minutes before testing.

• In all 4 routines, the athletes did 3 further bursts (20-30 seconds long) of press-ups or knee-ups 12 minutes, 8 minutes and 4 minutes before testing.
• Protocol 5 (P5) was  done after the other 4 routines where protocol 4 was done again but this time in survival garment (Blizzard Survival Garments, UK) for passive heat retention.
• The performance testing done after the warm-ups was as follows:

–          3 repeats (each 3 min. apart) of 20 m sprints pulling a weighted sled (75 kg for females and 15 kg for males) with timing gates at 20m.

Background –

• Recent analysis shows that 79% of research shows that warm-up improves performance
• Bob-skeleton is a winter Olympic sport where athletes push a sled for 20-30m before jumping into the sled. Average temperature during competition is appx. 5◦C to -40◦C.
• Typically, athletes did a warm-up outside 30 minutes before racing.

Considerations and Conclusions –

• Magnitude of the difference between conditions was interpreted using a Cohen’s effect statistic where: <0.2 trivial, 0.2-0.6 small, 0.6-1.2 moderate, 1.2-2.0 large, and >2.0 very large.
• All modified protocols were associated with faster sled pulls than the athlete’s standardised warm-up (P1): P1 vs P2 (p=0.01, ES= 0.6), vs P3 (p=0.000, ES=1.5), vs P4 (p=0.001, ES=1.0) and vs P5 (p=0.000, ES=1.8). P3 (p=0.000, ES=1.0), P4 (p=0.003, ES=0.4), and P5 (p=0.000, ES=1.2) showed significantly faster mean sled pull times than P2; while P3 (p=0.005, ES=0.6), and P5 (p=0.001, ES=0.9) faster compared to P4 and P5 (the addition of a heating garment) was significantly faster (but at a small effect size) compared to P3 (p=0.004, ES=0.3).
• The subjects preferred P5 and P4 to P3 and P2

Synopsis and Findings of Study-

• By Ian Shrier, MD, PhD
• Published September 2004 in the Clin J Spor Medicine  Volume 15 |Number 5| pages  267-273
• This was a review of 23 studies compiled from MEDLINE and Sport Discuss relating to the effects of stretching on performance.
• The articles were divided into two categories: 1) the studies examining acute bout so stretching – within 60 minutes- on performance   2) Effects of regular long-term stretching over days to weeks.
• The studies included just randomized controlled trials, cross-over trials (each subject is used as his/her own control), and repeated measure studies.

Background –

• Stretching has been said to help performance because it changes passive visco-elastic properties which in turn decreases muscle stiffness so less energy is required to move limbs thereby possibly increasing force/speed of contraction.
• On the other hand, decreased stiffness may decrease stored “recoil energy” which would increase energy requirements.
• The author cautions against interpreting studies that only test stretching effects on one factor of performance test (such as only on force or only on running economy).

Considerations and Conclusions –

• 22 of the 23 reviews suggested no benefit of acute stretching on isometric force, isokinetic torque, or jumping height. The measures included MVC, power, jump height, jump force, and jump velocity.
• 1 study found static stretching detrimental for jumping but that dynamic stretching had no effect.
• 1 article suggested that acute stretching it improved running economy but of the 2 articles that examined running speed, only one suggested that stretching helped, while 1 said it was detrimental and the 2 others had equivocal results. (the study population was limited to subjects with tight hip flexor and extensor muscles in the study where running economy improved due to stretching)
• Concerning regular longer term stretching, 9 studies covered this (effects of repeat stretching) over days and weeks and 7 of those 9 suggested it was beneficial and the 2 that showed no effect were only looking at the performance test of running economy. None of them said it was detrimental.

• The negative  effects of acute bouts of stretching  were observed for (1) static, ballistic, and proprioceptive neuromuscular facilitation (PNF) stretches; (2) males and females; (3) competitive and recreational athletes; (4) children and adults; (5) trained or untrained subjects; and (6) with or without warm-up. Similar results were found across study designs. There was limited research on the effect of the muscle’s preexercise tension and of contraction velocity. With regard to running speed, the results are conflicting.

• Overall evidence strongly suggests regular long term stretching does in fact increase isometric force production and velocity of contraction but the 4 studies investigating running economy only 1 showed improved performance from long term stretching as evidenced by an improved 50 yd dash time. This suggest that “contraction velocity or force is more important in short sprints than running economy and the effects of long term stretching on long distance running is yet to be seen.

• Acute bouts of exercise does decrease visco-elastic behavior of muscle and tendon and whith this decreased stiffness it takes less energy to move muscle but the reason stretching reduces performance seems to be the damage caused by stretching. It only takes movement 20%  beyond normal resting fiber length to cause strain and muscle damage and this occurs in some sarcomeres with just walking so it can been seen why stretching would cause

• The author states that acute bouts of stretching actually decrease visco-elasticity and increase stretch tolerance but long term stretching over 3-4 weeks improves ROM not because it improves visco-elasticity but instead just because it improves stretch tolerance. This is evidence by the fact that long term stretching does not help running economy. He states that the improved performance from long term stretching could be due to stretch-induced hypertrophy.

Synopsis and Findings of Study-

• By CHARLES CHATTONG, LEE E. BROWN, JARED W. COBURN, AND GUILLERMO J. NOFFAL at Human Performance Laboratory, Department of Kinesiology, California State University, Fullerton, California
• Published September 20010 in the Journal of Strength and Conditioning Research  34(7), 1751-1754
• This study included 20 college age men ( mean age 22.45 ± 1.73, mean height 176.83 cm ± 6.67, mean weight 76.98 kg ± 8.56 who had at least  1 year of resistance training experience.  None of them had any current or previous injuries that would affect results.
• The subjects were brought in for 5 testing sessions that were to determine the effects of varying levels or external resistance (this study used a weighted vest) box jumps on subsequent vertical ump performance.
• Each day they performed a 5 minute warm-up on a cycle ergometer at a self-selected RPM level of 25 W . After this they performed 3 countermovement jumps with arm swing to get a baseline measurement for that day. Their vertical jump height was measure on a Vertec.  The rest time between each jump was 10-15 seconds in accordance to what has shown appropriate in other studies.
• Subjects then performed 5 jumps onto a box the height of their lateral femoral condyle and after a 2 minute rest they then did 3 more vertical jumps. Day 1 was the control condition and this was all done the same for all subjects with no weight.
• For the rest of the days, the subjects randomly performed one of 4 conditions – doing the 5 jumps with 5,10,15 or 20% of their BW. Everything else was done exactly the same as day 1.
• There was no significant interaction of condition by time for vertical jump height but their was a significant main effect for time (p<0.05). with posttest jump height being greater (22.99 ± 3.35 in.) than pretest jump height (22.69 ± 3.37 in.)
• By this it was concluded that vertical jump height increased regardless of protocol indicating that the box jumps increase performance with or without the added resistance. The weigh vests had no added effect on performance.
• Although Burkett et al. found that vertical jump performance was increased with an added resistance of 10% of BW, that study differed from this in that a 25 in. box was used regardless of subject’s height and this study used the height of the subject’s lateral femoral condyle height which on average was 20.47 in. ranging from 19.5 inches to 23 inches and Burkett et al. only used one level of resistance.

Background

• “A specific dynamic warm-up can be described as a warm-up that addresses key muscle groups and the necessary neuromuscular coordination needed to perform a specific action, such as the vertical jump.”
• Studies have investigated PAP induced from specific dynamic warm ups coupled with heavy resistance (dumbbells or barbells mimicking movements) had a positive effect on subsequent activities such as jumping and sprinting. This is because PAP occurs when performing a contraction at or near maximal intensity. PAP has been associated with phosphorylation of mysosin regulatory light chains, increased recruitment of higher order motor units and a possible change in pennation angle.

Synopsis and Findings of Study-

• By DANNY J. MCMILLIAN,1 JOSEF H. MOORE,2 BRIAN S. HATLER,3 AND DEAN C. TAYLOR at 1U.S. Army MEDDAC, Heidelberg, Germany; 2U.S. Army-Baylor University Doctoral Physical Therapy Program, U.S. Army Medical Department Center and School, Fort Sam Houston, Texas 78234; 3Keller Army Community Hospital, West Point, New York 10996.
• Published September 2006 in the Journal of Strength and Conditioning Research  20(3), 429-499
• This study involved thirty cadets ( 16 men mean age 20.2 ± 1.2 years, mean height 182.4 ± 6.6 cm and mean weight 88.8 ± 9.0 kg; and 14 women mean age 20.4 ± 1.5 years, mean height 167.1 ± 7.9 cm and mean weight 64.0 ± 7.8 kg) recruited from club sports (either members of rugby and lacrosse – who were competing weekly –  or strength and conditioning teams) at the United States Military Academy (USMA). All subjects were in had weekly physical routines.
• Subjects were screened and excluded if had acute impairment of spine or lower extremities, vestibular dysfunction or balance disorder, or history of neurological disorders affecting upper or lower extremities.
• The subjects performed 2 different warm-up routines – dynamic warm-up (DWU) and static-stretching warm up (SWU) and no warm-up routine (NWU) on 3 consecutive days. Each session lasted 10 minutes (NWU involved 10 minutes of rest).  The order was counterbalanced to avoid potential biasing effects associated with test sequence.
• The Dynamic warm up routine was as follows:

Calisthenics: Perform 10 repetitions of each exercise at a slow to moderate cadence unless otherwise indicated. All component movements are required for each repetition.

Bend and reach-  Reach high overhead. Squat and reaching between the legs, allowing the back to flex, but keeping the heels down. Return to the starting position. Perform at a slow cadence.

Rear lunge and reach –  Start with hands on hips. Lunge to the rear while simultaneously reaching overhead. Return to the starting position in one motion. Repeat with the opposite leg. Keep most of the weight on the front leg. Lunge progressively further and deeper with each repetition. Keep the abdominals tight to maintain a stable trunk. Perform at a slow cadence.

Turn and reach –  Stand with arms extended to the side at shoulder level with the palms up. Turn to the left and pause while keeping the pelvis facing forward. The arms should now be directed forward and rearward. Return to the starting position, then repeat to the other side. Keep the abdominals tight throughout. Keep the head directed forward throughout. Perform at a slow cadence.

Squat –  Start with hands on hips. Squat until the thighs are parallel to the floor (or to your tolerance). Keep the heels on the floor. The arms should be raised to shoulder level for counterbalance.

Rower – Start in the supine position with arms overhead, head a few inches off the ground with the chin slightly tucked. In one motion, raise to a seated position, bend the knees to bring the feet flat, and bring the arms parallel to the ground.

Power jump- Start with the arms high overhead, with the feet, knees and hips aligned vertically. Squat and reach toward the ground with the arms outside the legs, keeping the back straight. Jump and reach overhead, landing in the squat position described above. Return to the starting position.

Prone row –  From the prone position with the arms overhead and several inches off of the ground, begin by raising the chest slightly and bringing the hands back to shoulder level in a rowing motion. Maintain abdominal muscle tension throughout the exercise. The hands and elbows remain parallel to the ground at all times. Maintain the neck in a neutral position.

Push-up –  At the starting position, the hands are directly under the shoulders or slightly wider. Elbows are straight, but not locked. The abdominals are contracted to maintain the trunk in line with the thighs. Do not lower the trunk past the point at which the upper arms are parallel to the ground. Perform at a moderate to fast cadence.

Windmill – From a relatively wide stance with the arms extended sideways and palms down, squat, bend forward and rotate the trunk to the left in order to reach the right hand to the left foot. Return to the starting position, then repeat to the opposite side. Keep the arms directed in opposite directions. Avoid excessive flexion of the spine.

Diagonal lunge and reach – Start with the arms high overhead. Lunge diagonally forward to the left while simultaneously lowering the hands to the lower leg. Return to the starting position in one motion. Repeat to the right. Keep the foot of the forward leg directed to the front, rather than in the direction of the lunge. Keep the trunk straight and the head up. Do not allow the knee of the forward leg to go beyond the toes or lateral to the foot.

Movement drills: Perform each exercise over a 20- to 25-m segment. Pause for 10–15 seconds of rest and return to the start point. This completes 1 repetition. Perform 1 repetition of each exercise. Maintain a slow to moderate pace unless otherwise indicated.

Verticals Run –  forward on the balls of the feet, raising the knees to waist level and maintaining a tall, upright stance. Use strong arm action to support the movement. Hands should move from waist to chin level with an approximately 90_ bend in the elbows throughout. There should be no backswing of the legs with this drill.

Laterals-  Stand perpendicular to the direction of movement, in a slight crouch with the back straight. Step to the side by rising slightly and bringing the trailing leg to the lead leg. Quickly hop to the side and land back in the crouch with the knees shoulder-width apart. Face the same direction for the down and back segments.

Crossovers –  Stand perpendicular to the direction of movement, in a slight crouch with the back straight. Cross the trailing leg to the front of the lead leg and step in the direction of travel to return to the starting position. Then cross the trailing leg to the rear of the lead leg and step in the direction of travel to return to the starting position. Repeat this sequence to the 25-yd stopping point. Face the same direction for the down and back segments. Let the arms swing naturally side to side to support balance. Allow the hips to swivel naturally.

Skip –  Step and then hop, landing on the same leg, followed by the same action with the opposite leg. Use strong arm action to support the movement. Hands should move from waist to chin level with an approximately 90_ bend in the elbows throughout. When the right leg is forward, the left arm swings forward and the right arm is to the rear. When the left leg is forward, the right arm swings forward and the left arm is to the rear.

Shuttle sprint –  Run at a moderate pace to the 25-yd line. When nearing the line, slow the movement, make a quarter-turn clockwise, plant the left foot parallel to the line, and squat or bend in order to touch the ground at the line. Run back to the starting line, turning counterclockwise to touch the ground with the right hand. Run back to and through the 25-yd line, gradually accelerating to near maximum speed.

• The stating stretching routine involved the following stretches: Overhead arm pull, turn and reach, rear lunge and reach, hamstring stretch and calf stretch, quadriceps stretch, posterior hip stretch, trunk flexion/extension stretch  – Subjects performed 1 repetition of each stretch to each side. Stretches were held 20–30 seconds unless otherwise indicated.

• The subjects then performed one of 3 tests (also counterbalanced) 1-2 minutes after warm-up. The tests included:

1)      The 5 step jump – to measure functional leg power

2)      The medicine ball throw for distance – to test total-body power

3)      The T-drill – to measure agility. (forward and backward points of the T-drill set at 5m rather than 10 yd to emphasize lateral movement)

• All tests were conducted at the same time at the same site on an empty stomach (6am).
• The tests were done as follows:

5-step jump From a parallel stance behind the starting line, subjects maximally jump from both legs to land on the left leg. Without stopping, maximally jump to the right leg, back to the left leg, back to the right leg and finally stopping with a 2-leg landing. The distance from the starting line to the back of the most rearward heel is recorded. The jump must be repeated if the subject falls backward on the final landing. Measurement was recorded to the nearest inch (based on preexisting floor markings) and converted to meters. The average of 2 trials was used for statistical analysis. Trials in which either graders or subjects noted execution errors were not recorded.

T-drill – Three cones are set 5 m apart on a straight line. A fourth cone is placed 5 m from the middle cone to form a ‘‘T.’’ The subject starts at the cone at the base of the T. The grader gives the signal to go and starts the stopwatch. The subject runs to the middle cone and touches the cone, then side steps 5 m to the left cone and touches that cone. The subject side steps 10 m to the far right cone and touches that cone, then side steps 5 m back to the middle cone and touches that cone. The subject runs 5 m backwards past the base of the T. The grader stops the watch when the subject passes the base of the T. Measurement was recorded to 0.01 of a second. The average of 2 trials was used for statistical analysis. Trials in which either graders or subjects noted execution errors were not recorded.

Medicine ball underhand –throw for distance From a parallel stance behind the starting line, subjects maximally throw a 9-lb medicine ball using an underhanded toss. Subjects are encouraged to use countermovement as long as the feet remain parallel on the ground until the ball is released. The feet may leave the ground and cross the starting line as the ball is released. The grader will measure the distance from the starting line to the point where the ball first lands. Measurement was recorded to the nearest inch (based on preexisting floor markings) and converted to meters. The average of 2 trials was used for statistical analysis. Trials in which either graders or subjects noted execution errors were not recorded.

* The order of testing was counterbalanced over the 3 days of testing.

• Results indicated that DWU increase performance modestly in all 3 tests relative to SWU and NWU(p < 0.01).
• There was no significant change in performance between SWU and NWU for T-drill and medicine ball throw for distance but SWU  significantly improved performance for 5 step jump over NWU

Background –

• It’s been stated that the purpose of pre-exercise warm-up “is to increase muscle and tendon suppleness to stimulate blood flow to the periphery, to increase body temperature, and to enhance free, coordinately movement.
• Active warm-up may also decrease muscle stiffness by “breaking stable bonds between actin and mysosin filaments, through stretching likely has the same effect”

Considerations and Conclusions –

• Gleim et al, in a review stated that flexibility should be specific to sport and “decreased flexibility might actually increase economy of movement in sports such as distance running, where only the mid-portion of the ROM is used.
• Limitations in the study include that only 3 repeated measures were  conducted due to limited availability of participants so combined effects of dynamic and static stretching warm-up was not conducted.

Synopsis and Findings of Study-

• By Avery D. Faigenbaum*; James E. McFarland†; Jeff A. Schwerdtman*; Nicholas A. Ratamess*; Jie Kang*; Jay R. Hoffman* at *The College of New Jersey, Ewing, NJ; †Hillsborough High School, Hillsborough, NJ
• Published Journal of Athletic Training 2006;41(4):357–363
• This study examined the acute effects of 4 warm up protocols with and without weighted vest on anaerobic performance in high school athletes.
• It involved 18 high school female athletes. Mean age 15.3 ± 1.2 years, mean height 166.3 ± 9.1 cm, mean weight 61.6 ± 10.4 kg with resistance training and dynamic warm up experience.
• Subjects first performed 5 minutes of jogging and then randomly performed 1 of 4 warm up protocols- 1) five static stretches (2 x 30 seconds), 2) Nine moderate-intensity to high intensity dynamic exercises,3) the same 9 dynamic exercises with a weight vest 2% of body mass, 4) the same 9 dynamic exercises with weighted vest 6% of body mass.
• After this vertical jump, long jump, seated medicine ball toss, and 10 yd sprint were performed
• The static stretches included: hip and lower back stretch, chest and hamstring stretch, lying quadriceps stretch, calf stretch, triceps and side-bend stretch
• The dynamic warm up exercises included: speed skips, heel kicks, toes in toes out, trunk twists, skipping straight-leg toe touches, drop squat carioca, push-ups, sprint series, high knee skip

Considerations and Conclusions-

• Vertical jump was significantly great after dynamic warm up and dynamic warm up with 2% weight vest compared with static stretching
• Long jump performance was significantly better with dynamic warm up with 2% weight vest.
• No significant differences were observed for seated med. Ball toss or 10 yd sprint.

Synopsis and Findings of Study-

• By Susan C. Gray, Giuseppe Devito, and Myra A. Nimmo  at Strathclyde Institute for Biomedical Sciences, University of Strathclyde, Glasgow, UNITED KINGDOM
• Published September 2002 in the Med. Sci. Sports Exerc., Vol. 34, No. 12, 2091-2096
• This study was to determine if active warm-up (high and low intensity) would increase acetyl group availability sufficiently to alter metabolism during subsequent exercise.
• The participants included 6 healthy females (mean age 26 ± 4 years, mean height 1.64 m ± 0.06, mean weight 60.9 ± 4.0 kg, mean percent bodyfat 24.2 ± 3.7%, mean peak oxygen uptake – Vo2 peak  43.3 ± 5.5 and mean power output – PO max – 239 ± 26
• Subjects were tested 7 and 10 days after onset of menses and again appx. 12 days after ovulation because it has been shown that metabolic response to intense exercise does not differ between these two phases of menstrual cycle.
• Peak oxygen uptake was tested directly by continues incremental cycling test to volitional exhaustion on an electronically braked cycle ergometer. Test was initiated at 70 W and increased by 35 W every 2 min. for first 6 min. and same every minute until could not complete workload.
• The 6 subjects performed  30 s sprint at 120% of their maximal power output on an electronically braked cycle ergometer 5 min. after undertaking an active warm-up. This was done at the same time every day from 9am-11am in an environmental chamber (that remained 22 degrees Celsius with a relative humidity of 35%). to control changes in environmental conditions
• Temperature was taken when subjects first arrived with a rectal thermistor probe and a muscle biopsy of one leg was taken.
• The subjects then waited 20 minutes and either underwent an active warm up (AW or underwent a control trial (C)  )

The AW consisted of cycling at 40% PO max for 5 min at a cadence of  60 rev ·min_1 followed by a 1-min rest period, then four 15-s sprints (120% POmax, 120 rev·min_1), with a 15-s recovery period separating each sprint. On the alternate visit, subjects undertook a control trial (C). On this occasion, before exercise, subjects’ legs were passively heated to the same preexercise Tm as that induced by the active warm-up (determined either from familiarization or the main trial). This was achieved by wrapping an electric heat blanket around both legs from the ankle to the gluteal fold.

• The control lasted on average 32 minutes.

Background-

• It’s been stated that warm-up alter metabolic responses in subsequent exercise and that this is because of increased blood flow and so O2 deliver to muscles after active warm-up but Bangsbo et al. has shown that O2 supply to contracting muscle is in excess of demand in initial phase of dynamic exercise and that o2 delivery is not limiting for Vo2 (oxygen uptake) of contracting muscle.
• As a result of that study, it seems likely that another metabolic response during exercise preceded by warmup is result of difference in o2 deliver to active muscle and  evidence suggest mitochondrial acetyl group availability may partly determine relative contribution made by anaerobic and oxidative ATP contraction.

Considerations and Conclusions –

• Active warm-up significantly increased the concentration of acetylcarnitine from 4.5  1.5 mmol·kg dry muscle (dm)1 at rest to 9.4  1.6 mmol·kg dm1 before the onset of exercise. There was no change in acetylcarnitine concentration in C. During exercise the accumulation of muscle lactate was  significantly less in AW compared with C (21.9  3.8 vs 34.3  2.3 mmol·kg dm1, respectively)
• Active warm-up caused less accumulation of both blood and muscle lactate during intense exercise which suggest less reliance on energy derived from anaerobic sources.

Synopsis and Findings of Study-

• By Torbjorn Soligard, 1 Grethe Myklebust, Kathrin Steffen, Ingar Holme, Holly Silvers, Mario Bizzini, Astrid Junge, Jiri Dvorak, Bahr, Thor Einar Andersen, a
• Published BMJ 2008;337:a2469 doi:10.1136/bmj.a2469
• This study randomized 125 different football clubs for south, east, and middle Norway and separated them into an intervention group (which included 65 clusters) and a control group (which included 60 clusters) and followed them for one league season (8 months) to see effects of detailed warm-up program on risk of injury.
• The groups included 1892 female players aged 13-17 (mean age 15.4 (SD 0.7) ). There were 1055 players in the intervention group and 837 players in the controlled group.
• The intervention group went through a detailed warm-up program to increase strength, awareness, and neuromuscular control during static and dynamic movements.
• The injuries that were to be watched and measured for were to lower extremities including – foot, ankle, lower leg, knee, thigh, groin, and hip.
• All clubs involved trained two times a week in addition to play and practiced two to five times a week and played between 15-30 matches during the season.
• The FIFA Medical Assessment and Research Centre developed warm-up program consisting of 3 parts –1) running exercise at slow speed combined with active stretching and controlled contacts with partner, 2)six different sets of exercise including strength, balance, and jumping exercise each with three levels of increasing difficulty, and 3) speed running combined with football (soccer) specific movements with sudden changes in direction.
• The complete exercise program was to be used as a warm-up for ever training session and  the running exercises in the program for the warm-up for every match.
• Emphasis was put on improved awareness and neuromuscular control during standing, running, planting, jumping, and landing and quality of movement was encouraged in teaching the warm-up.
• The program was taught to the coaches of the teams by the researches but the coaches were to remain in contact with researches during the process and fill out weekly data in forms.
• The warm-up program was as follows:

Table 1 | Revised warm-up exercise programme used to prevent injury in young female footballers

Exercise Repetitions

I. Running exercises, 8 minutes (opening warm up, in pairs; course consists of 6-10 pairs of parallel cones):

Running, straight ahead 2

Running, hip out 2

Running, hip in 2

Running, circling 2

Running and jumping 2

Running, quick run 2

II. Strength, plyometrics, balance, 10 minutes (one of three exercise progression levels each training session):

The plank:

Level 1: both legs 3×20-30 seconds

Level 2: alternate legs 3×20-30 seconds

Level 3: one leg lift 3×20-30 seconds

Side plank:

Level 1: static 3×20-30 seconds (each side)

Level 2: dynamic 3×20-30 seconds (each side)

Level 3: with leg lift 3×20-30 seconds (each side)

Nordic hamstring lower:

Level 1 3-5

Level 2 7-10

Level 3 12-15

Single leg balance:

Level 1: holding ball 2×30 seconds (each leg)

Level 2: throwing ball with partner 2×30 seconds (each leg)

Level 3: testing partner 2×30 seconds (each leg)

Squats:

Level 1: with heels raised 2×30 seconds

Level 2: walking lunges 2×30 seconds

Level 3: one leg squats 2×10 (each leg)

Jumping:

Level 1: vertical jumps 2×30 seconds

Level 2: lateral jumps 2×30 seconds

Level 3: box jumps 2×30 seconds

III. Running exercises, 2 minutes (final warm up)

Running over pitch 2

Bounding run 2

Running and cutting 2

Background –

• Most common injuries in soccer are related to knee and ankle ligament and thigh muscle strains and women may be at greater risk than men as rate of ACL injures is three to five times higher for girls than boys.

Considerations and Conclusions –

• The intervention group played 49 899 hours of football (16 057 hours matches and 33 842 hours of practice) and the control group played 45 428 hours (14 342 matches and 31 086 practice).
• There were 376 injuries during the study – 161 from the intervention group and 215 from the control group. 299 (80%) acute, 77 (20%) overuse. Overall incidence of injuries was 3.9 (SD 0.2) per 1000 player hours (8.1 (SD 0.5) in maches and 1.9 (SD 0.2) in training.
• The rate ratio for players in intervention group to control group was 0.71 (0.49 to 1.03, p= 0.072) therefore there was significantly lower risk of injuries overall (both overuse and severe) in the intervention group.
• Compared with control group, fewer players in intervention group had two or more injuries but a reduction in risk of re-injuries did not reach significance.
• Overall the study showed that the risk of injury in general can be reduced about one third and that severe injuries can be reduced as much as one half.
• The main injuries that were watched and studied did not show to be significantly reduced by the intervention protocol but secondary outcome variables (including rate of severe injuries, overuse, and total injuries overall) were.
• Results may be slightly skewed and the protocol may have been more effective if both players and coaches were more compliant to following the protocols with concentration as intended.

Synopsis and Findings of Study-

• By Anthony D. Kay and Anthony J Blazevich   at Sport Exercise & Life Sciences, The University of Northampton, Northampton, UNITED KINGDOM; and School of Exercise, Biomedical & Health Sciences, Edith Cowan University, Joondalup, Western Australia, AUSTRALIA
• Published  2011 in the Medicine & Science In Sports & Exercise Vol. 44, No. 1, pp. 154–164, 2012
• This study was a review of peer reviewed articles including randomized or quasi-randomized controlled trials as well as intervention based trials collected from MEDLINE, ScienceDirect, SPORTDiscus, and Zetoc.
• The review was to comprehensively review if the literature supports the claim that acute stretching has a negative effect on immediate subsequent performance, specifically on strength-, power- and speed dependent tasks.
• 4550 articles were searched and 106 met the criteria. Last search was conducted on February 16, 2011.

• Data from articles were taken. The factors taken into account were: stretch duration, muscle group stretched, maximal muscular performance outcome measures and whether significance was reached or not.
• Research was separated into two groups of stretch duration <30 or 30-45s or either 1-2 or >2min. but only 10 studies included stretching <30s. 25 studies were found for longer duration stretching protocols (30-45s) and most found no reduction in performance.

Background –               

Considerations and Conclusions- 

• The review found that only stretching lasting longer than 60s ( >60s) caused a negative effect on performance.
• 55% of articles reviewed showed reduction in performance tasks in question after acute stretch but 69% showed no such reduction.
• The conflict in finding could be due to studies reporting  effects of acute static stretch on sever variables within same study including: different muscle groups, muscle lengths, contraction modes, contraction velocities, duration of stretch and performance tasks.
• Most studies focused on lower body so knee flexor/extensor and plantar flexor/extensor strength was examined (being most common) and divided again into studies where stretching lasted ≤45 s and ≥60s. Knee flexors seemed to be more influenced by stretch than the rest showing that test exercises influenced results in some studies. Significant reductions in hand grip strength was shown to decrease from short duration static stretch but chest press 1RM did not.
• The research shows that these performance variables can be reduced only in total stretch durations lasting longer than 60 s but it is only a “moderate effect” and those lasting less than 45 seconds seem to have no effect on subsequent performance. There is only a minor difference in muscle contraction and no substantial effect of movement velocity.
• There is a need for effects of short-duration stretches on eccentric strength.

Synopsis and Findings of Study-

• By David G. Behm, Andrew Bambury, Farrell Cahill, and Kevin Power  at School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John’s, Newfoundland, CANADA
• Published Med. Sci. Sports Exerc., Vol. 36, No. 8, pp. 1397–1402, 2004.
•  This study was to study effect of acute static stretching on lower limb balance, proprioception, reaction (RT) and movement time (MT).
• It consisted of sixteen healthy males, university students, (age =24.1 ±7.4 yr, weight =71.5 ±15.4 kg, height =172.3 ± 6.5 cm)
• This study focused on a moderate volume stretching routine because studies in the past have used prolonged (15-30 min per single muscle groups) in the past which does not represent real world protocols.
• Subjects had  pre-a and post test which involved a 20 min. period of maximal voluntary isometric contraction (MVC)  force of leg extensors, static balance using a computerized wobble board, reaction and movement time of dominant lower limb, and ability to match 30% and 50% MVC forces with and without visual feedback
• Subjects first had a warm-up of a 5 min. cycle on a cycle ergometer (Monark Ergomedic 828E0 at 70 rpm with 1-kp resistance.
• The stretching of the quadriceps, hamstrings and plantar flexors(unilateral kneeling knee flexion (quadriceps), hip flexion with extended leg while supine (hamstrings), extended leg dorsiflexion while standing (stretch of the plantar flexors with gastrocnemius emphasis), and flexed knee dorsiflexion while standing (stretch of the plantar flexors with soleus emphasis)  was then randomized and the stretches were held at “threshold of discomfort” for 45 s with a 15 se recovery period between stretches. The stretching occurred 2 minutes after pretesting and the subjects were allowed to rest 1 min. before posttesting began after the stretching. This was the intervention group.
• The control condition just performed the 5 min cycle warm-up and then were allowed to rest appx. 26 min. between pre and posttesting – appx the same time it would take for the intervention group to complete all the stretching.
• The duration of pre- and posttesting for both grips was appx. 20 min.
• For leg extension MVC, subjects sat on bench with knees and hips flexed at 90 degrees and ankle was inserted into high tension wire to a Wheatston bridge configuration strain gauge.
• 3 minutes was allowed in between contractions.
• Subjects were asked to exert sufficient isometric leg extension force over a 5-s period to match the gridlines. Visual feedback was always given for the first three trials of a particular relative force (30% or 50% MVC), while the computer screen was obstructed from view for the subsequent three trials.

Background- 

• Acute changes in MTU length, stiffness, force output and muscle activation (those effects theorized from stretching) could  alter ability to detect (afferent proprioception) and respond (efferent muscle activation) to changes in immediate environment.
• At this time, this was the only study that addressed the effect of stretching on balance, proprioception or reaction/movement time.

Considerations and Conclusions-

• Isometric force production was not significantly reduced after stretching in this study like it has been shown in some other studies and the researchers propose that this may be due to the moderate stretching routine as opposed to the long duration of other studies.
• There was no significant difference in MVC with stretch and control conditions but there was in balance (P <0.009) ( decrease 9.2%) compared with control (increase 17.3) and reaction time (P <0.01)  from 4.0% and 1.9% in the stretch protocol to 5.8% and 5.7% in the control.

Synopsis and Findings of Study-

• By Tom K. Tong and Frank H. Fu at Department of Physical Education, Hong Kong Baptist University, Hong Kong, China
• PublishedEur J Appl Physiol (2006) 97: 673–680 DOI 10.1007/s00421-006-0233-6
•  This study was to examine the effects of inspiratory muscle (IM) arm up on maximum dynamic IM function and max reps of 20-m shuttle run in Yo-Yo intermitted recovery test
• The study involved 10 health young males who played various sports including soccer, rugby, etc.
• Before testing forced spirometry and aerobic capacity were assessed.
• Subjects were to perform identical maximum dynamic IM function test and Yo-Yo intermittend test in three conditions. This was the randomly
• The three conditions were:1) without IM warm up (control) 2 and 3) with IM warm up by performing  two sets of 30 breaths with inspiratory pressure-threshold equivalent to 15% (IMWp) and same with  40% (IMW ) maximum inspiratory mouth pressure.

Considerations and Conclusions-

• This suggests that specific IM warm-up in IMW may entail reduction breathlessness sensation, partly attributable to the enhancement of dynamic IM functions, in subsequent exhaustive intermittent run and, in turn, improve the exercise tolerance.

Synopsis and Findings of Study-

• By DAVID J. SZYMANSKI,1 KYLIE E. BASSETT,1 ERIK J. BEISER,1 MEGAN E. TILL,1 GREG L. MEDLIN,1 JASON R. BEAM,2 AND COOP DERENNE3 at 1Department of Kinesiology, Louisiana Tech University, Ruston, Louisiana; 2Department of Health, Exercise, and Sports Science, University of New Mexico, Albuquerque, New Mexico; and 3Department of Kinesiology and Rehabilitation Science, University of Hawaii at Manoa, Manoa, Hawaii
• Publishedin J Strength Cond Res 26(1): 199–205, 2012
•  This study was to examine the best warm up device to produce the greatest bat velocity for softball players.
• It included 19 D1 intercollegiate softball players. Mean age 19.8 ± 1.2 years, mean height 167.0  ± 4.7 cm, mean weight 69.2 ± 8.6 kg, lean body mass 49.6 ± 3.6 kg, % bodyfat 27.9 ± 5.9
• The subjects performed a warm up with 1 of 8 resistance devices on separate days. Each of 8 testing sessions began with a dynamic warm up, 3 maximal dry swings with assigned warm up device, 2 comfortable dry wings with standard 83.8 cm, 652-g (33 in, 23 oz) softball bat followed by 3 max game swings (20 seconds rest between swings)
• Bat velocity (BV) was measured by a Setpro (SPRT5A) chronograph and recorded in meters per second.
• The warm up devices included: standard Louisville Slugger TPS 83.8 cm, 652 g (33 in., 23 oz) aluminum softball bat, 6 overweighted implements that included 2 new products on the market, and 1 lighter bat.

Considerations and Conclusions-

• The 1 x 3 repeated measures ANOVAs indicated no significant differences in bat velocity between the 3 swings with standard game bat after any of the warm up devices.
• These findings are similar to male baseball players indicating that effects are similar.
• It is recommended no to use a donut ring as this produced the most negative effect and that excessively light or heavy implements should not be used.

Synopsis and Findings of Study-

• By Jeffrey C. Pagaduan , Haris Pojskić, Edin Užičanin, Fuad Babajić at College of Human Kinetics, University of the Philippines – Diliman, Philippines.and Faculty of Physical Education and Sport,Tuzla University, Bosnia and Herzegovina
• Publishedin the Journal of Human Kinetics volume 35/2012, 127-132 DOI:10.2478/v10078-012-0086-5
•  This study was to assess the effects of warm-up strategies on countermovement jumps in college football players (mean age 19.4 ± 1.1 years; mean height 179.0 ± 5.1 cm; mean weight 73.1 ± 8.0 kg; mean body fat 11.1 ± 2.7%) from Tuzla University who all had 6.5 ± 2.1 years of competitive experience and participated in 10 hours per week of football training and 3 hour per week in strength and conditioning.
• All tests were done from 8-10am and sessions were separated by 48 hours.
• There was 7 days of testing the first being just for anthropometric measures. The rest of the warm-up protocols were as follows:

1)      Done on day 2 – general warm-up

2)      General warm-up with dynamic stretching

3)      General warm-up, dynamic stretching, and passive stretching

4)      Passive static stretching

5)      Passive static stretching and general warm-up

6)      Passive static stretching, general warm up and dynamic stretching 

Synopsis and Findings of Study-

• By J. Brian Church, Matthew S. Wiggins, F. Michael Moode, and Randall Crist at Murray State University, Murray, Kentucky 42071.
• Publishedin the J. Strength Cond. Res. 15(3):332–336. 2001.
•  This study was to determine effect of 3 different warm-up protocols on vertical jump performance
• 3 vertical jumps were taken averaged, and recorded from a Just Jump system before and after warm-up protocols to compare heights and participants were allowed to take a 1-step approach to incorporate SSC. A sit and reach test was also taken pre- and post.
• 40 female NCAA Division 1 athletes volunteered (tennis, rowing, volleyball, jumpers, throwers, and sprinters) ages 18-22 years (mean 20.3 ± 16 years)
• The subjects performed one of three warm up routines on 3 nonconsecutive days
• The routines were as follows:

1)      General warm-up only – familiar bodyweight circuit of 10 exercises each performed for 20 seconds. The ywent from less to more vigorous and the rest between exercise was 10 seconds. The entire warm-up lasted 5 minutes.

2)      General warm-up (same as above) and static stretching focusing on hamstrings and quads (side quad stretch, semistraddle kneeling quad stretch, butterfly, sitting toe touch, and forward lunge)

3)      General warm-up (same as above)  and PNF (contract-relax agonist –contract (CRAC) – of hamstrings and quads. A partner stretched the muscle to tightness, the subject then isometriclly the antagonist muscle for 10 seconds followed by an isometric contraction of the agonist muscle for another 10 seconds followed by another passive stretch of the antagonist muscle. Repeated 3 times for each muscle group.

Background-

• Research has shown that increased joint mobility from acute stretching effects may cause injury due to decreased joint stability
• Studies have also shown that flexibility increases may have more to do with increased muscle temp than decrease in stiffness of muscle tendon unit (MTU).
• The decreased force production that may be caused due to stretching has been attributed to increased slack in the tendon by Rosenbaum and Hennig, meaning that the muscle contracts but it takes a short amount of time before this slack is taken up.
• Static stretching is believed to reduce natural contraction of muscle when it is taken to ROM extremes quickly (the myogenic reflex) which in turn creates a more relaxed MTU capable of greater ROM.

Considerations and Conclusions-

There was a significant reduction in performance with PNF as compared to the other protocols (p<0.05)

• There was no significant increase in flexibility in any protocols (p = 0.44).

Synopsis and Findings of Study-

• By KAZUKI TAKIZAWA1, TOSHIO SOMA2, KAZUNORI NOSAKA3, TOMOJI ISHIKAWA4, & KOJIRO ISHII at 1Institute for the Advancement of Higher Education, Hokkaido University, Sapporo, Japan, 2Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan, 3School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia, 4Department of Health and Sports, Niigata University of Health and Welfare, Niigata, Japan, and 5Faculty of Health and Sports Science, Doshisha University, Kyoto, Japan
• Published 22 Aug 2011  European Journal of Sport Science, 12:6, 455-461
• This study was conducted to determine muscle temp. after warm-up exercise and to test hypothesis that repetitive submaximal concentric contractions before eccentric exercise would reduce extend of DOMS and the decrease in muscle strength of elbow flexors maximal eccentric strength.
• The study included ten male college students (mean age 18.8 ± 0.5 years, mean height 173.6 ± 6.1 cm, mean weight 62.3 ± 7.9 kg) who were physically active and played recreational sports but who had not been in resistance program for at least 6 months.
• Participants performed two bouts of eccentric exercise of elbow flexors with warm-up exercise for one arm (warm-up group) and without warm-up exercise (control) for opposite arm separated by 4 weeks. The use of dominant and non-dominant arms was randomized and counterbalanced. This was taken before and after warm-up exercise.
• Temperature of biceps brachii was taken (with deep body thermometer) and muscle activity was assessed by EMG was taken and recorded before warm-up, after warm-up and every 24 hours for 5 days following exercise.
• Warm-up consisted of 100 concentric contractions of elbow flexors based on studies of Nosaka & Clarkson, 1997)
• An isokinetic dynamometer was used to measure two maximal voluntary isometric contractions for 5 s with a 60-s rest between contractions and the warm-up exercise was completed 5 min. before eccentric exercise.
• Muscle soreness of biceps brachii was also assessed afterward by visual analogue scale consisting of a 100-mm line with “no pain” at one end and “extremely sore” at other while applying pressure to the muscle.

Considerations and Conclusions-                             

• Muscle temp. of biceps brachii was 34.8 ± 0.1 ◦C before warm-up and increased significantly (P <0.01) to 35.8 ± 0.2 ◦C after warm-up and immediately before eccentric exercise pre-exercise muscle temp was significantly higher (P <0.01) for warm-up than for control 34.4 ± 0.2 ◦C
• There was no significant change in %iEMG between control and warm-up or over time.
• Muscle soreness developed after eccentric exercise and peaked 2-3 days after no differences in soreness was observed between control and warm-up
• MVC was not significantly different between groups and decrease on average in both by 25.8 ± 3.4% immediately after exercise and was lower than baseline by 18.4 ± 4.2% 5 days post exercise
• Warm-up increased muscle temp by 1.4 ◦C but has no effect on reducing decreased muscle activity or decreasing DOMS in eccentric exercise for elbow flexors.
• Nosaka and Clarkson (1997) had shown that it did decrease DOMS but the same warm-p protocols were  used in this study and the results were not reproduced.

Synopsis and Findings of Study-

• By ALEXANDER J. KOCH,1 HAROLD S. O’BRYANT,2 MARGARET E. STONE,3 KIM SANBORN,2 CHRISTOPHER PROULX,2 JOE HRUBY,2 ELIZABETH SHANNONHOUSE,2 RHONDA BOROS,2 AND MICHAEL H. STONE41 at Truman State University, Kirksville, Missouri 63501; 2Appalachian State University, Boone, North Carolina 28608; 3Carmichael Training Systems, Colorado Springs, Colorado 80909; 4United States Olympic Committee, Colorado Springs, Colorado 80903.
• Publishedin J. Strength Cond. Res. 17(4):710–714. 2003.
•  This study was to determine the effect of 3 warm-up routines on standing broad jump (SBJ) performance
• The study included Thirty-two subjects (16 men, 16 women). Twenty-one of the subjects (8 men, 13 women) were apparently healthy college students enrolled in a weight-training class (6 weeks) and were considered untrained. The remaining subjects (8 men, 3 women) were sprinters and jumpers from the University’s NCAA division I track and field team and had a history of strength training for several years. The mean age for subjects was 20 ± 3 years, mean weight 73.92 ± 11.02 kg, mean height 172 ± 9 cm and 1RM squat = 93.2 ± 37.kg
• 1RM was tested and the subjects were experienced in squatting.
• Their broad jump was also tested and recorded and tested again on 4 separate days after 1 or 4 warm-up routines. Each test session was separated by 3 days.
• 3 broad jump trials were tested after each warm-up routine in rapid succession. This was done immediately after the warm-up routines and then again 15 minutes after again.
• The warm up routines were as follows:

1)      High-force (HF) warm-up  – sets of low rep squats performed at relative high % 1RM (1 x 3 of 50, 75 and 87.5% of 1RM) 3 minutes rest was given between sets.

2)      High Power Warm-Up (HP) low rep speed squats ( 1 x 3 at 20,30, and 40% 1RM) 3 minutes rest between sets.

3)      Stretching Warm-up (ST) consisted of 8 minutes of various static stretching exercises performed with 10 second holds (standing toe touch, standing quadriceps stretch, seated toe touch, seated quadriceps stretch)

4)      No activity warm-up (NA) – 8 minutes quiet sitting followed by 3 initial jumps, resting again for 15 minutes and then 3 additional jumps(post-test).

Considerations and Conclusions-

• T tests showed significantly higher 1RM squats for men vs. women (p< 0.001) and athletes vs. non –athletes (p < 0.001). The same was true for other tests. The trained women were as strong as the untrained men.
• None of the warm up routines produced significant increases in broad jump performance (p = 0.157) but a strong correlation (R= 0.805) was found between 1RM squat and SBJ.

Synopsis and Findings of Study-

• By ANIS CHAOUACHI,1 CARLO CASTAGNA,2 MOKTAR CHTARA,1 MATT BRUGHELLI,3 OLFA TURKI,1 OLIVER GALY,4 KARIM CHAMARI,1 AND DAVID G. BEHM 5 at 1Tunisian Research Laboratory ‘‘Sport Performance Optimization’’, National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia; 2School of Sport and Exercise Sciences, Faculty of Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy; 3School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup,Western Australia, Australia; 4Laboratory Actes-Physiology, Noumea, New Caledonia; and 5School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada A1C 5S7
• Published J Strength Cond Res 24(8): 2001–2011, 2010
• This study was to investigate effects of static and dynamic stretching alone and then in combination with each other on subsequent agility, sprinting, and jump performance.
• It involved twenty two highly trained male student athletes (elite athletes from different professional teams or individual sports of nation first division of Tunis) pursuing exercise science and physical ed. Degrees from University of Sports of Tunisia. The mean age was 20.6  ± 1.2 years, average height 179.4 ± 6 cm, lean weight 71.9 ± 8.1 kg, mean % bodyfat 10.6 ± 2.9%.
• The subjects had 10 sessions (48 hrs apart) including a 2 part orientation session in which they were familiarized with the stretching exercise and performance tests.
• The subjects started with a 5 min general warm up then performed one of the stretching conditions, then did a 5 min specific explosive warm up followed by a 2 min rest interval before performing one of 4 tests: sprint, countermovement jump, agility, 5-jump
• Subjects performed at least a 5-minute self-paced general warm-up (EG1) consisting of low- to moderate-intensity aerobic exercise including 3 minutes of forward jogging, 1 minute of sidestepping, and 1 minute of jogging backwards, followed by 10 minutes of a designated stretching protocol (or 10 minutes of rest for the control group) before completing a specific explosive warm-up (EG2) consisting of 5- to 7- minute incremental intermittent sprint and agility runs. These sprint and agility runs included three-quarter pace running: 10-m forwards, repeated twice; 10-m sidestepping, repeated 5 times; 30-m forward, repeated 3 times, a set of 8 single hop jumps, and a set of 8 alternate leg bounds (side hop), repeated twice; and 45-m forward run with 5 3 90changes of directions, repeated twice. Intensity was then increased: three-quarter pace for 10 m and full pace for 20 m, repeated twice, and full pace for 30 m. This type of explosive warm up after stretching has been shown to causeminimal decrements to power-based performance
• The stretches consisted of 4 different exercises to stretch plantar flexors, hip flexors, hamstrings, hip extensors, and adductors.
• Eight different stretching protocols: (a) static stretch (SS) to point of discomfort (POD); (b) SS less than POD (SS,POD); (c) dynamic stretching (DS);(d) SS POD combined with DS (SS POD DS); (v) SS,POD combined with DS (SS,POD DS); (vi) DS combined with SS POD (DS SS POD); (vii) DS combined with SS,POD (DS SS,POD); and (viii) a control warm-up condition without stretching were implemented with a prior aerobic warm-up and followed by dynamic activities.

Considerations and Conclusions-

• No stretching program with any intensity negatively affected these elite athletes who were nonsprint-trained.
• The control condition (4.2 6 0.15 seconds) showed significant differences (p = 0.05) for faster times than the DS SS,POD (4.28s 6 0.17) condition in the 30-m (1.9%) sprint. There were no other significant differences. The lack of stretch-induced impairments may be attributed to the trained state of the participants or the amount of time used after stretching before the performance. Participants were either professional or national level elite athletes who trained 6–8 times a week with each session lasting ;90 minutes.
• Based on these findings and the literature, trained individuals who wish to implement static stretching should include an adequate warm-up and dynamic sport specific activities with at least 5 or more minutes of recovery before their sport activity.

Synopsis and Findings of Study-

• By Fernando Naclerio1 Avery D. Faigenbaum2 Eneko Larumbe-Zabala3 Nicholas A. Ratamess2 Jie Kang2 Paul Friedman2 Ryan E. Ross2 at 1 Centre of Sports Sciences and Human Performance, School of Sciences, Greenwich University (UK) 2 Human Performance Laboratory, Department of Health and Exercise Science, The College of New Jersey Ewing, NJ 08628 3 Department of motor and Training European University of Madrid (Spain)
• Journal of Strength and Conditioning Research Publish Ahead of Print DOI: 10.1519/JSC.0b013e318295d7fb
• This study examined acute effects of different parallel squat post activation potentiation protocols with and without whole body vibration on jumping performance in college athletes
• It involved fifteen male athletes (8 American football players and 7 baseball players). Their mean age was 20.3 ± 1.3 years, mean height 179.50 ± 5.3 cm, mean weight 81.0 ± 10.8 kg with at least 2 yrs resistance training experience and no experience with whole body vibration protocols.
• It was a randomized repeated measures counter balanced design where participants served as their own controls.
• The subjects each came in for 19 different sessions
• The subjects first performed either 3 sets of 3 (high volume protocol) or  1 set of 3 (low volume protocol) of either parallel squat with 80% of max without vibration (NV-PS) parallel squat with 80% of max on whole body vibration platform (WBV-PS) (1.963 mm amplitude and 40 Hz) or a control.
• Each time 3 countermovement jump and the best drop jump was performed to see effects of conditions.

Background-

• Whole body vibration plates increase the gravitational load on subject while exercise or standing on it.

Considerations and Conclusions-

• Significant improvements were observed for countermovement jump height after 4 min. recovery using low volume regardless of condition
• For the whole body vibration protocol, a significantly lower drop jump height was observed after 1 min. following both low and high volume.
• PAP may be specific to the movement it is trying to improve which would explain why a squat would help a countermovement jump

Synopsis and Findings of Study-

• By Thomas Little and Alun G. Williams at 1Sport, Health, and Exercise, Staffordshire University, Staffordshire, UK; 2Institute for Biophysical and Clinical Research into Human Movement, Manchester Metropolitan University, Alsager, UK.
• Published J. Strength Cond. Res. 20(1):203–207. 2006.
• This study was to examine effects of different modes of stretching within a pre-exercise warm-up on high speed motor capacities such as countermovement vertical jump, stationary 10-m sprint, flying 20-m spring, and agility performance of professional soccer players.
• There were 3 different warm-ups and they included – static stretching, dynamic stretching, or no stretching.
• The study consisted of eighteen pro soccer players from  Enlgish League Premier Division Club tested during the 2001-02 season.
• They performed 3 different warm-up protocols on 3 nonconsecutive days (at least 48 hours after match or hard training) all within 1 week.
• Before any of the warm-up protocols were implemented the subjects performed 4 minutes of general warm-up including: 2 minutes of jogging, 1 minute of sidestepping and back jogging, and 1 minute of further jogging.
• Then they performed 6 minutes and 20 seconds of static stretching or dynamic stretching except for in the no stretch protocol. The gastrocnemius, hamstrings, quadriceps, hip flexors, gluteals , and adductors were all stretched in the static protocol. A 20 second rest was allowed between each stretch. All static stretches were held for 30 seconds each leg within pain threshold. The dynamic stretches was performed for 60 seconds at a rate of appx. 1 stretch cycle every 2 seconds of unilaterally for 30 seconds. The dynamic stretches included the backward run (for quads) lateral lunge (for adductors) drop lunge (for gluteals) and straight-leg march (for hamstrings) and heel to toe walk (for gastrocnemius).
• The non stretch protocol just rested for 1 minute after general warm-up before performing the tests.
• 2 minutes rest was given between each trial and test

Considerations and Conclusions –

• There was no significant difference in any of the  warm-up protocols for vertical jump (p= 0.074)
• There was no significant different in any warm-up protocols for acceleration but dynamic stretching resulted in a significantly superior performance  p= 0.025 than no stretching
• Static and dynamic stretching was significantly better for maximal speed (20 m test) than no stretching (p < 0.0005.

• Immediately after the warm-ups, vertical jump (with Just Jump System) and long jump were tested each one time at maximal effort. Duration or warm-up and testing was appx. 10-20 minutes.

• The authors suggest that sprint performance may not be affected much by activation of the core anyway because other research shows low to moderate correlations between sprint performance and strength of trunk muscles.

Synopsis and Findings of Study-