Training Zones

HR zones use % of max HR (standard 5-zone model). The Karvonen method uses heart rate reserve (HRR = max − rest) for a more personalized result.

Coggan power zones are the industry standard 7-zone model used by most training software. Z4 (threshold) should feel hard but sustainable; Z5 should feel very hard.

Finding max HR: 220 − age is an estimate with ±10–20 bpm error. A field test (warm up, then 3–5 all-out minutes) gives a real number.

Finding FTP: Ride 20 min as hard as you can sustain. FTP ≈ 95% of average power. Or use a formal ramp test.