There’s lots to like about the idea of high intensity interval training (HIIT). It’s time efficient, you burn more energy in a shorter period of time and what’s more, you’ll raise your metabolism and keep that burn going. You’ll also increase your cardiovascular fitness faster than with longer less intense workouts.
The basic idea of HIIT is to push yourself at maximal effort for short periods of time with periods of rest in between, keeping the overall workout short – 30 minutes or less.
However, the benefit to risk ratio needs to be taken into account, especially if you’re new to exercise. While ‘maximal effort’ is subjective and dependent on your starting point, if you’re new to exercise pushing yourself to the upper levels of your capability can increase your risk of injury, especially if any mobility, flexibility or technique issues are not addressed before you get started. Spend some time building up your base fitness and technique and use interval training at a lower intensity before an all-out HIIT effort.
If you’re more accustomed to sitting at a desk for 8 hours or more a day, jumping straight into a HIIT session will also raise your risk of injury and the benefits of this sort of workout will not outweigh the effects of sitting for such long periods of time on a daily basis. Consider how you can make movement a more constant part of your day instead.
Consistently pushing yourself at the high intensities that HIIT encourages can lead to overtraining symptoms which not only affects your risk of injury but can also affect your immune system, sleep, appetite and stress responses. Its usually recommended that this kind training is limited to a maximum of 3 times a week to give body adequate recovery time – this is definitely a case where more is not better.
While there’s great benefits to HIIT workouts, remember that achieving optimal health and fitness comes down to listening to your body, exercising at the appropriate level and incorporating variation.