| HIIT is a borderline strength training. Consider Tabata protocol. It is supermaximal effort protocol, participants are required to exert maximum effort repeatedly. The duration of active phase of Tabata is 20 seconds, half of approximately 40 seconds after which maximum performance (power output) drops significantly, because body switches to a different energy system. In my experience, Tabata squats are done in range of 16-21 per 20 seconds of active phase. So, basically, Tabata squats are equal to somewhat less than 8 sets of 16-20 repetitions done close to failure. The failure usually come after first active phase, so that's why there are "somewhat less than 8 sets." I personally define failure as breakage of exercise form or exercise pace, and this is what I and others experience in Tabata squats. And you know what? If you go close to failure, muscle mass and strength grow in the range of 5 to 35 repetitions [1]. [1] https://www.youtube.com/watch?v=dN_c4sQwfTI PS Other HIIT protocols are similar. For example, 3 one-minute-active-phase-one-minute-rest supermaximal protocol also leans close to "3 sets of 35 repetitions done to failure" - squats' pace noticeably quickly deteriorate to 1 squat in two seconds. |