This is a question I received from a Brazilian Jiu Jitsu teammate of mine.

He will be wrestling for school this winter and would like to drop weight for competition.

Topic: High Intensity Interval Training (HIIT)

Q: I never did these before but am thinking about starting. I did my first session today and it really kicked my ass. I just ran the long way of the track and walked on the turning curves. Are there any dangers to these? Should I do them only 3 times a week? I want to burn a lot of calories, and I read they are supposed to burn calories even when you do nothing. I feel my chest burning even later. Any risk of heart attacks or such things?

A: Hey, HIIT is probably one of the fastest ways to burn fat. You just have to be careful because you don’t want to burn too much too fast, which is common among people using an isocaloric diet. It’s also very anaerobically demanding so you might not want to do it on a day you do weights. The best way to do it is if you have a heart rate monitor, if you do let me know and I can show you how to design a program that’s best for you. If not I usually recommend people use a 1:2 work to rest ratio. 30 second sprint and 1 minute rest. You can also do this with other exercises like sprawling or breakfalls. Do as many sprawls or breakfalls as you can within :30 and then rest for 1:00 minute. You could even alternate the two exercises if you wanted.

HIIT causes EPOC (excess post-exercise oxygen consumption) for up to 48 hours. So you’ll be burning fat even while you sleep. Just make sure you’re not over training.

As long as you’ve had an up to date physical and your doctor thinks regular exercise is ok I see no problems.