While all-out HIIT protocols are very effective, other low-volume HIIT models that consist of relatively intense, but submaximal, constant-load efforts (e.g., 10 x 60 s at a fixed work intensity that elicits ~90% of maximal heart rate, interspersed by 60 s of recovery) have been shown to induce rapid physiological and performance adaptations similar to Wingate-based training.
As little as six sessions of HIIT over 2 wk, using a protocol that entails only 2-3 min of all-out exercise within a training session that lasts ~20 min (i.e., repeated Wingate Tests), can increase skeletal muscle oxidative capacity, reduce non-oxidative energy provision during submaximal exercise and markedly improve performance during tasks that rely mainly on aerobic energy metabolism.While long appreciated by endurance athletes as an integral component of training programs designed to maximize performance, short-term studies lasting up to several weeks in healthy persons of average fitness have established that HIIT per se is a potent stimulus to induce physiological adaptations that resemble changes typically associated with traditional endurance training, despite a lower total exercise volume and reduced training time commitment.High-intensity interval training (HIIT) is generally characterized by repeated sessions of brief, intermittent exercise, typically at intensities that elicit ≥85% of peak oxygen uptake (VO 2peak), and interspersed by periods of rest or low-intensity exercise for recovery.