training
HIIT (High-Intensity Interval Training)
Short bursts of near-maximal effort alternated with recovery — time-efficient for fitness but not magic for fat loss.
High-Intensity Interval Training alternates hard efforts (e.g. 20–40 s near-maximal) with easier recovery periods. It improves VO2 max and insulin sensitivity in less time than steady-state cardio and produces a modest post-exercise "afterburn" (EPOC). For fat loss, though, that afterburn is small and total calorie balance still governs results; HIIT mainly helps by burning calories efficiently and preserving muscle when paired with resistance training. Because it is demanding, 2–3 sessions per week is plenty for most people — excess high-intensity work can elevate cortisol and impair recovery.
Primary Sources
- Wewege M et al. "The effects of high-intensity interval training vs. moderate-intensity continuous training on body composition." Obes Rev. 2017.
- Keating SE et al. "A systematic review and meta-analysis of interval training versus moderate-intensity continuous training on body adiposity." Obes Rev. 2017.