Power meters, heart rate straps and good old feel. Which should you train with? The answer is all three, for different jobs.
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Feel (RPE)
Rate of perceived exertion: how hard it feels, often on a scale of 1 to 10. Free, always available, and it takes everything into account: fatigue, heat, stress, sleep.
Good for: everyday riding, beginners, and knowing when something is off.
Watch out: it can drift with mood and motivation, and is harder to compare week to week.
Heart rate
Shows how hard your body is working. Cheap and useful for steady efforts.
Good for: easy rides and long steady efforts, and spotting fatigue or illness when it runs high or low.
Watch out: it lags behind effort, so it is poor for short intervals. Heat, caffeine and fatigue shift it too.
Power
Measures what you are actually producing, instantly and precisely.
Good for: intervals, pacing time trials and climbs, and tracking progress.
Watch out: it does not tell you what that power costs you on the day. Power meters cost money.
Use them together
Power tells you what you did. Heart rate tells you what it cost. Feel tells you how you coped. When power is normal but heart rate and feel are high, you are tired. When power is up and feel is easy, you are getting fitter.
Set power zones with our power calculator and see power testing for cyclists.
Use power for cycling intervals, types and zones, heart rate and feel for easy days.
Short efforts: go by power or feel, not heart rate.
Decoupling
One useful trick is to look at how heart rate and power drift apart over a long steady ride. If power stays the same but heart rate keeps rising, your aerobic fitness or fuelling is the limiter. If they stay close together, you are in good shape for that duration. It is a simple way to track endurance without a test.
RPE scale
1 to 2: recovery, very easy.
3 to 4: endurance, conversational.
5 to 6: tempo and sweet spot, short sentences.
7 to 8: threshold to VO2max, a few words.
9 to 10: all out.
When numbers lie
Heat, altitude, illness, poor sleep and caffeine all change heart rate. A power meter can drift if it is not zeroed. Feel catches what both miss. Use all three and trust the pattern.
Train with us
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