HIIT Timer — 5 RoundsFree HIIT timer for 5 rounds. Customizable work/rest intervals for a complete 10-minute high-intensity workout. Start instantly — no download.Frequently asked questionsHow long does a 5-round HIIT workout take?With 40s work and 20s rest, 5 rounds = 5 minutes of exercise. A full session with warm-up and cool-down takes 15–20 minutes. Use the 10-minute preset for a mid-length session.What exercises work best for 5 rounds of HIIT?Compound movements maximize calorie burn: burpees, jump squats, mountain climbers, high knees, and kettlebell swings. Rotate exercises across rounds to avoid fatigue in a single muscle group.Is 5 rounds of HIIT enough for a workout?Yes — 5 rounds at true maximum intensity provides significant cardiovascular and metabolic benefit. Research shows even 4 minutes of true all-out HIIT (Tabata protocol) produces results comparable to much longer moderate-intensity sessions.What is the best work-to-rest ratio for 5 rounds?For conditioning: 40s work / 20s rest. For power: 20s work / 40s rest. For beginners: 30s work / 60s rest. The ratio determines the metabolic demand — shorter rest develops anaerobic capacity, longer rest develops explosive power.How many calories does a 5-round HIIT workout burn?A 10-minute maximum-intensity HIIT session burns approximately 80–150 calories during the workout, plus additional calories through the afterburn effect (EPOC) for up to 24 hours post-exercise.