Circuit Training Vs Interval Training: What's The Difference?

Circuit training and interval training sounds similar, but they're two different types of workouts entirely. While circuit training means shifting between different exercises throughout your workout — a circuit of pushups, squats, kettlebell swings, box jumps, and crunches, for example — an interval workout isn't focused on what you're doing, but instead, how hard you're doing it (via Shape). 

Circuit workouts are great for boosting your heart rate while strengthening muscles, making them the best of both cardio and strength-training worlds for busy people who struggle to make time for training more than a couple of hours each week. "If you're looking for a full-body workout in 30 minutes or less, circuit training does the trick," Dr. Michael Smith told WebMD. A typical circuit will move between eight and 10 exercises lasting anywhere from 30 seconds to three minutes each, and can be done with equipment at the gym or with bodyweight at home (via Ace Fitness). 

Interval workouts are fairly open-ended. Often, they are more cardio-based and will have a singular focus, like running, cycling, or rowing. Other times, they'll focus on a single exercise, like burpees, and sometimes, they incorporate a circuit-style series of exercises into a set. Typically an interval set is done with body weight exercises for practicality and safety, making it a great option for when you're stuck at home. As long as you're working hard followed by a period of rest and repeating that process, you're doing an interval workout (via the Mayo Clinic).

Because often the two types of workouts are combined in a class — a bootcamp that sets a time goal to get through a series of circuits before taking a break and moving on to the next timed set, for instance — it's not a question of which workout to do, it's a question of how often you should do high-intensity workouts like these. Don't be concerned if sometimes the two workout types are used interchangeably. Some coaches will refer to a circuit-type workout as an interval workout because you're resting between exercises or sets. Always look at what the actual workout is comprised of, rather than focusing on what it's called (via Livestrong). 

But do be concerned if you're doing circuit and interval training at a high intensity more than a couple of times per week. "If you do too much high-intensity training it could cause overtraining, which can cause adrenal fatigue and disrupt the hormone balance in your body," Pete McCall, a personal trainer and spokesperson for the American Council on Exercise, told Shape.