This morning I was listening to someone talk about their friend that goes to Heart Rate-based Group Fitness classes. Their friend regularly brags that they burn 500-600 calories per work out and that they keep burning calories for hours after their work out is finished.
There have been countless studies on the effects of High Intensity Interval Training (HIIT) and Variable Intensity Interval Training (VIIT) on oxygen consumption in the body. The main idea of oxygen consumption is that oxygen demand increases when you start exercising but when you stop exercising there’s a carryover effect called Excess Post-Exercise Oxygen Consumption (EPOC). During EPOC the body is trying to return all of its altered processes to normal homeostasis and it requires energy to do so. The impact of EPOC on weight loss is pretty much nil because the longer term slight elevation in burned calories is so small. In fact, basic strength circuit training has been shown to have very similar effects on EPOC. So, the idea of EPOC is very enticing from a marketing perspective but it is very misleading. When it comes to caloric burn from exercise, only doing the actual work (movement of any kind) causes meaningful calorie expenditure towards weight loss.
The incredible thing about HIIT and VIIT is its effect on body composition. No you won’t necessarily lose weight from doing strictly interval work because the prolonged caloric burn just isn’t there like it is with long duration steady state cardio (like 1.5-2 hours). BUT interval training changes the body by boosting signals for increased muscle growth and fat loss while also drastically boosting your fitness and suppressing your appetite. That means it can potentially help you lose inches, get much fitter, eat less, and be able to work out at higher intensities for even greater caloric burn during other exercise sessions in the long term.
To sum it up, if you just want to burn calories MOVE. If you want to get fitter so that you can burn even more calories and make significant changes in body composition, try interval training! Combined with a solid strength training program, you can transform your body in no time. At The Rack we have many tools for conditioning with interval training like the prowler, our Airdyne fan bike (aka “get me off this thing my legs are on fire”), our rower, as well as tons of options like medicine balls and farmers carry for circuit interval variations. Contact us today for more information on how you can get started!