HIIT Training: How Much Is Too Much?
High intensity interval training, or HIIT, is a workout style people love because it's quick, it's intense, and it's very efficient at burning calories. Tight schedules have made these workouts more popular, but is it possible to do TOO much?
HIIT training is a branding of the circuit workout style that's been long used to shed pounds while creating speed, agility, and power. In fact, the branding of this style is so popular now that it was named 2014's champion in the American College of Sports Medicine's annual list of top fitness trends!
But this is no fad, it's a scientifically-backed training style, and it's been proven to work. When going head to head with low intensity steady-state cardio, it's sometimes possible to burn over 60 percent MORE calories, while only working out for half the amount of time.
Defining HIIT Workouts
HIIT can be done in a variety of different ways, but is very often seen on cardio machines. Here, rounds of higher resistance and effort are followed by a quick cooling off period. The intervals exist because you simply repeat the process. A non-cardio machine HIIT style you may have heard of is the popular Tabata circuit training style. Tabata workouts generally involve strength movements, but at much higher intensity levels (more reps, and faster), along with lower weights. The intent behind Tabata and other circuit HIIT workouts are for fat burning and muscle endurance -- but not particularly for building strength. Building optimal strength would involve a completely different style of training, and often takes quite a bit longer. This contributes to why most people these days are opting for the speedier, more efficient HIIT style.
Dangers of Over-Doing HIIT
How hard you need to work to properly do HIIT lies in its name -- high intensity. Not just enough to make you sweat, but enough to make you sweat A LOT; think of sprints and other quick burst movements. At the end of the workout, you should be spent. And what that means is your body needs recovery, in order to be prepped for whenever the next round may be.
Because this style of training is so intense, it is very taxing on your muscles, joints, and nervous system. If you start going at it for five days a week, you're either not working hard enough, or working way too hard. What you need to to is intersperse lower intensity training, as well as days of rest. This is in order to both switch up the style, and prevent extreme wear and tear on the joints. Exhausting your system can only work for so long before your body starts to get used to it, or starts to shut down due to the intensity levels. Therefore a recovery period of sorts is necessary to help your body get back to full strength -- and the next HIIT workout!
I would recommend only doing two or three HIIT workouts in a week, and no more than 20-30 minutes per HIIT workout. Like with heavy weight training, your body needs to return to full (or near full) strength in order to perform optimally. If you're doing HIIT the right way, it should feel like three workouts in a week is ALL that you can do. In the case that some folks out there are also including a few separate strength workouts in a week, definitely limit the HIIT workouts to two. Strength gains, as well as fat burning, becomes less effective when your body is trying hard to recover.
Definitely work out hard, but be smart about it. If you listen to your body, and make sure to include days of less intense work, and you should get the results you're looking for in no time.