Heart Rate Zones Guide: Train Smarter with HR Monitoring

Calculating Max Heart Rate

The simplest formula: 220 minus your age. A 35-year-old has an estimated max HR of 185 bpm. More accurate formulas exist (Tanaka: 208 - 0.7 x age) but the simple method works for most people.

The Five Heart Rate Zones

Zone 1 (50-60% max): Very light effort. Recovery and warm-up. You can easily hold a conversation. Ideal for active recovery days.

Zone 2 (60-70% max): Light effort. The fat-burning zone. You can talk comfortably. Build your aerobic base here — 60-80% of training should be Zone 2.

Zone 3 (70-80% max): Moderate effort. Aerobic endurance. Speaking in sentences becomes harder. Good for tempo runs and steady-state cardio.

Zone 4 (80-90% max): Hard effort. Lactate threshold. Only a few words at a time. Used for intervals and race-pace training.

Zone 5 (90-100% max): Maximum effort. Short bursts only (30 seconds to 3 minutes). Develops speed and VO2max.

Which Zone Burns Most Fat?

Zone 2 burns the highest percentage of calories from fat, but higher zones burn more total calories. For weight loss, total calorie burn matters more than the fat-burning percentage. A mix of Zone 2 (most sessions) and Zone 4-5 (1-2 sessions/week) is optimal.

Heart Rate Monitors

Chest straps are most accurate. Wrist-based optical sensors (smartwatches) are convenient but less reliable during intense exercise. For Zone 2 training, wrist monitors are usually accurate enough.