Last updated: 3 October 2026
Reviewed by Jordan Morley, FA Level 2 Football Coach
HIIT alternates intervals of near-maximal effort (80-100% max HR) with recovery periods. Tabata (20s work/10s rest × 8 rounds) is the most researched protocol, originally studied at 170% VO2 max. HIIT produces cardiovascular adaptations comparable to much longer steady-state training in significantly less time. Research shows 20-30 minutes of HIIT 2-3 times per week produces substantial aerobic improvements. Limitations: HIIT requires genuine high effort to be effective; most gym-goers perform 'pretend HIIT' at moderate effort that doesn’t match the research. Also: DOMS and CNS fatigue demand 48h recovery between sessions.
- Alternating maximal effort + recovery
- Tabata: 20s/10s × 8 = 4 minutes
- Matches longer steady-state training in less time
- Requires genuine near-maximal effort
In practice
HIIT alternates short bursts of near-maximal effort with brief recovery periods, producing cardiovascular and metabolic improvements comparable to much longer steady-state sessions in a fraction of the time — but the 'high-intensity' part is non-negotiable; sessions done at only moderate effort lose most of the time-efficiency benefit that makes HIIT valuable in the first place.
FAQ
Is HIIT better than steady-state cardio?
Neither is universally 'better' — HIIT offers time efficiency and strong cardiovascular/metabolic benefits, while steady-state cardio is gentler on recovery and easier to sustain for longer durations; many programmes combine both.
How often should HIIT be done per week?
Most guidelines recommend 2-3 HIIT sessions per week, since the high intensity requires more recovery time than easy steady-state cardio and excessive frequency raises injury and burnout risk.