I’m a fan of any kind of HIIT, Interval, or Circuit classes. The mixture of weights and cardio is really going to challenge your body and truly shape it and make you stronger. I personally love the variety since I’m the type of person that gets bored easily. I’ve put together a list of studios and gyms (in no particular order) that offer these types of classes. I hope you’ll check them out.

 | Heart-rate based interval training using treadmill, rowing machines, TRX and free weights. Constantly changing up the sequence to give you a very well-rounded workout. You can also see how many calories you burn each class using their heart rate monitor. Try it out: First class is free!

 | Check out their primal endurance and strength series. Each class is only 30 minutes and stackable, meaning you can do two or three back-to-back. They focus on either speed and mobility drills for endurance or kettle bells and other dynamic exercises for strength training. I’d recommend doing both for a full body workout. Try it out: For newbies, you get 4 day passes to visit the gym and Saturday primal classes are free.

 | Burn Cardio offers a variety of classes that are circuit classes, however I really want to highlight the Metcon (short for metabolic conditioning) class. The goal of metabolic conditioning is to train your body to work at a higher intensity and increase the efficiency of storage and delivery of energy. At Burn it is a full-body 30 min workout that incorporates bodyweight movements and TRX exercises at varying intensities. Try it out: Start with the free 2-day pass and take as many classes as you want.

 |  Grab a board and try City Surf Circuits. It’s 50 minute cardio, balance, and strength class. Think jump squats, burpees, wall sits, lunges, sandbag slams, and sometimes even battle ropes are incorporated into the class. Each exercise is broken into 10-15 different stations and you do them for only 30 seconds before moving on to the next one. Try it out: Drop in rate is $22.

Even yogis need to cross train. Check out the High Interval Yoga class. It offers cardio and strength training and ends with a very relaxing cool down period. Try it out: For newcomers, 10 days for $10 or a $15 drop in

| The first indoor cycling studio to introduce a TRX Hybrid Ride. It’s a small class that combines a 25 minute ride followed by strength training with the suspension ropes for a full body workout. Try it out: First two classes are on the house for new clients. $25 drop in if you’re not.

 Grit HIIT is 30-minute-long high-intensity interval training class complete with the use of 6 or 8 pound medicine balls and a killer playlist. Try it out: Get your first week for $10 or $25 drop in.

The Tread55 class offers Intervals to the max. Shorter segments than normal on both the treadmill and the floor will keep your heart rate racing. Six to minute intervals of treadmill sprints/hills/runs, plyometrics, dumbbell work and core-strengthening exercises will render your body tapped out but FIT beyond belief. Try it out: Drop-in classes are $20.

Tsunami and Tsunami 60 are both HIIT classes centered around the IndoRow machine. There are four stations which include rowing, legs, core, and arms. Participants push themselves through up to two minutes of high intensity work with minimal rest as they rotate through stations.  All exercises are low-to-no impact, protecting the joints while challenging the muscles.  The Bike Bands & Balls class is a 55-minute cycling. Participants alternate between intervals of work on the bike and resistance work using BOSU balls, resistance bands, Dynamax balls, and other fitness “toys”. Try it out: For newcomers, Crowbar Cardio offers an unlimited week of classes for $25.

| The core fusion extreme class is a high intensity interval training class that pushes you to your limit. You’ll move through power stations consisting of high intensity work followed by brief moments of active recovery. This hour of power will incorporate gliders, heavy hand weights, a plyo box, suspension training, cardio explosions and intense core work to push you to to your fitness maximum. With a balance of restorative stretches at the finish, this functional, time-savvy, expertly tailored class will take you to the extreme. Exhale also offers core fusion barre, yoga, sport and others under the Core Fusion family. Try it out: Drop-in classes are $25

| At Beyond500, the Pilates inspired interval training class incorporates cardio on their unique Curve treadmills, kettlebells, and controlled movements on a Pilates chair to help you burn at least 500 calories per class. Beyond500 offers different class formats and no class sequence is exactly the same. Try it out: For new clients, try two classes for $25. Drop in rates are $25.

 Sweat offers a variety of different bootcamp and interval classes. Bootcamp uses body weight exercises, strength training, and interval training to push members harder for a full body workout. Try it out: Drop in for a on Saturdays at 9am.

Bodybar’s Bootcamp is a high intensity workout designed to test your strength and stamina as you are led through intervals of strength training coupled with Tabata-style cardio exercises to optimize your workout. The class varies each week and may use the Cardio Chair, Jumpboard, and/or Bosu balance balls. Imagine the fast pace of a bodybar Express class with more equipment, more cardio, and more SWEAT to completely fatigue your muscles and change your body. This 60-minute class is 10 minutes longer than a typical bodybar class, but with the extra time you’ll enjoy a cool down and stretch at the end! However, there is a pre-requisite. You must take 1-2 Reformer or Reformer Jump! classes before you can take the bootcamp classes. Try it out:  For new clients, an intro class is $18 and drop-in rates are $30