High Intensity Interval Training (HIIT) is a staple in many exercisers routines for a good reason. This form of cardio can help boost your metabolism, improve endurance and scorch major calories in a short amount of time.
HIIT involves repeated intervals of intense work followed by complete rest. HIIT intervals are short. The intense cardio bursts are always less than one minute long, with the ideal time being about 20 seconds. Rest times are longer and can range anywhere from 30 seconds to several minutes.
I personally love (and hate) HIIT. It is time efficient and extremely effective. However, just like with all things in life (Netflix, cookies, wine…) there is such a thing as too much HIIT. In fact, doing HIIT too frequently can become counterproductive.
So, what is the downside of doing too much HIIT? Doing HIIT too often can take a toll on the body. Without proper recovery you will begin to see and feel decreased performance, poor sleep quality, and extra stress. You will also be putting yourself at a greater risk for injury.
But that’s not all. If you do HIIT too frequently, your body will stop feeling so challenged by it. The reason HIIT burns so many calories is the fact that your body is not used to that level of intensity. When you shock your body during a workout you instantly burn more calories and see better results. This is why when you start a new workout routine or new diet you see results quickly… you’ve confused your body into change. HIIT should be used a tool to confuse and challenge the body, but for best results it should be used selectively.
Because HIIT is so intense, you need more time in between sessions. Your body needs that extra rest to work properly. I am not saying you should cease exercising between HIIT sessions though. Try doing 1-2 HIIT sessions a week with low intensity cardio and moderate intensity weight lifting as your main form of exercise. This is the way I structure my MFit Membership program. If you are interested in programming ideas or a complete workout schedule, you should check out the MFit Membership at mollymcnamee.com/programs.
You will likely find that doing fewer HIIT sessions each week will make you stronger and more powerful in the HIIT workouts you do. Working out properly at a lower intensity will help you build the muscle you need to perform well in HIIT. Let me give you a personal example. A couple years ago I injured my wrist. I had been working on squatting heavier for a couple months and suddenly I had to stop. I was upset. But I continued to squat with a lighter weight for more reps while my wrist recovered. During this time I focused on form and proper glute activation. Once I felt comfortable loading more weight on the bar again, I found I was able to lift more than I did before the injury! The lesson here is you can’t train effectively at 100% intensity until you are able to master 70% first. Build your endurance and strength through multiple steady state cardio and resistance training sessions a week and then kill your HIIT session when it comes around every few days.