Free 30 minute HIIT timer for a complete 30-minute high intensity interval training workout. Science-backed duration for maximum fat burning and fitness gains.
30 minutes (5 warm-up + 20 HIIT + 5 cool-down) is considered optimal for most people. It provides enough total work for significant cardiovascular and metabolic benefits while being short enough that intensity can be maintained throughout. Sessions longer than 30 minutes often see declining intensity in later intervals.
Structured 30-min session: 5 min warm-up → 3 rounds of a 5-exercise circuit (each exercise 40s/20s = 5 min per circuit) = 15 min → 5 min finisher (Tabata on one exercise) → 5 min cool-down. This provides variety, prevents boredom, and ensures all major muscle groups are trained.
Varies by body weight and intensity: 150-lb person at high intensity: 350–450 calories. 200-lb person: 450–600 calories. Add 50–100 calories/hour for the next 12 hours (EPOC). Total 24-hour caloric impact: 600–800 calories for a 200-lb person at true high intensity. These estimates are for genuine HIIT, not moderate circuit training.
A 30-minute session allows one extra exercise circuit or a longer cool-down/finisher. You can include more exercise variety across the additional 10 minutes. Focus on starting with the most demanding exercises when energy is highest (rounds 1–2 of any circuit) and progressively lighter exercises toward the end.
3 sessions per week with rest days between is optimal for most people. Monday/Wednesday/Friday is a classic schedule. Beginners: start with 2 per week and add the third in week 3–4. Total weekly HIIT volume: 90 minutes is sufficient for significant fitness improvements when intensity is genuinely high.