Don’t do HIIT too often
HIIT, high-intensity interval training, are popular, maximal effort cardiovascular workouts. They are available at boot camps, certain gyms, and classes. What’s great about HIIT, is that it burns a lot of calories in a short period of time, increases endurance, and strengthens the heart.
What’s not-so-great about this type of workout is that it’s extremely taxing on the central nervous system, increases cortisol, increases likelihood of injury and cellular damage (1), and can make some people hungrier so they end up eating more calories than they typically do. Doing cardio has many benefits, and everyone should do some type of cardiovascular exercise.
A lot of people do HIIT classes several days in a row, and/or it’s their only form of exercise. Since these classes have strength elements, they should be spaced out because it takes at least two days for a muscle to repair. If you don’t give your body enough time to rest, you’re not building muscle, you are continually breaking it down. What this means is, two to three days a week is the maximum you should take these classes if they include weights or body weight exercises like push-ups and pull-ups.
If you love HIIT workouts, great, do them, but space them out, and do no more than three a week. If that upsets you because you want to exercise more than that, you can still walk, stretch, practice yoga, and do lighter cardiovascular exercises that bring cortisol down, instead of up. It’s typically not exercise that will make you lose fat, it’s how much you’re eating.
If intense cardiovascular exercises tires you out, causes you to binge, and wears down your immune system, you’re not alone. Some cardio is good, too much of anything yields negative results.
You don’t need HIIT classes to lose fat and be strong, I don’t. I lift weights, practice yoga, and do short bursts of cardio between weight lifting sets every now and then, and I’m lean, fit and strong. Listen to your body, and make health and fitness a priority.
Source: Comana, Fabio. “HIIT, HVIT, or VIIT: Which IT are you doing and do you know the differences?” NASM, 1 January 2018, https://blog.nasm.org/sports-performance/hiit-hvit-viit-know-differences/