HIIT how much time to do and rest

HIIT work and rest vary by protocol—from 20 seconds on and 100 seconds off to intervals lasting a few minutes each.

• Two-minute protocol: Do two minutes of hard effort, rest two minutes, then repeat for three rounds. Finish with a cool-down, such as walking slowly until your breathing recovers. 1
• Anaerobic endurance: Start with 2–3 sets of 20 seconds of intense effort followed by 100 seconds of rest; add one or two sets each week as you progress. 2
• 30 seconds on, 10 seconds off: This short-rest pattern can cause movement quality to deteriorate as fatigue builds, increasing injury risk—especially for movements requiring good form. 3
• Aerobic endurance: Run a mile, rest for as long as the mile took, then repeat. 4