The coach yells “TIME!” and you collapse on the floor in a heap of rubble. With muscles burning and heart thumping you try to stop time, but before you know it the coach is yelling again… “Next round starts in 3,2,1 – GO!”
HIIT (High Intensity Interval Training) has exploded recently as the “Flavor of the Month” within the fitness industry. Whether at a park bootcamp workout, at home with the latest Insanity DVD, or at one of those “gyms” that exclusively offer single-modality sweatfests, fitness enthusiasts are being exposed to repeated bouts of exhaustive effort with timed breaks.
There is nothing inherently wrong with intervals, we use them all the time at Synergy. The only problem is most people are doing HIIT wrong! Intervals should consist of repeatable bouts of work periods and RECOVERY periods. Most people/coaches/trainers, though, typically treat intervals as work periods and “not-work” periods.
The recovery portion of the interval affords you the opportunity to control your breathing, sustainably put forth consistent efforts of output, and continually stress the appropriate energy system. Without this opportunity for transition between activity and recovery, you effectively stay “active” even when “resting”. You can’t put forth consistent efforts in each interval as your physiology gets away from you. Your performance declines as your breathing rate (and therefore your heart rate) spike and your fuel depletes, which nullifies the intended benefits of the intervals.
If you aren’t focused on recovery (and trust me, it takes work) during rest periods of intervals then you’re really just enduring an aggressive sufferfest. And if that tickles your fancy, then have at it. Just don’t call it intervals; or training for that matter, because it’s neither one of those.