Why does my watch say I'm in Zone 2 when I'm gasping for breath?

Your zones are probably set wrong because your watch is using an inaccurate estimate of your maximum heart rate. Most devices use the formula 220 minus your age, which can be off by 10+ beats per minute, making all your zones misleading.

Are wrist heart rate monitors accurate enough for training?

They're decent for steady efforts but struggle with rapid changes, cold weather, and arm movement. Wrist sensors often lag behind reality or lock onto your running cadence by mistake, which is why chest straps that measure electrical signals directly are more accurate.

How do I find my actual maximum heart rate?

Warm up thoroughly, find a hill, and run three hard 3-minute efforts with recovery between them, pushing to maximum on the final one. The highest heart rate recorded is close to your true maximum, which you can then manually enter into your watch settings.

Your Watch Has Opinions

Your Watch Doesn't Know How Hard You're Working

Why heart rate zones are useful when set correctly but misleading when based on default formulas, dodgy wrist sensors, and blind faith in numbers over what your body is telling you.

1 November 202610 min read