CoachingAnswer

SHOULD I TRAIN BY FTP OR HEART RATE?

By Anthony WalshRoadman CyclingUpdated 26 May 2026

ANSWER

Both have a role. Power (FTP) is the more precise tool — it is real-time, unaffected by mood or heat, and directly prescribable. Heart rate tells you how much the effort is costing your body on that specific day. The best approach is to pace sessions by power and use heart rate as a second channel to check whether the physiological cost matches expectation. Use heart rate when you don't have power.

KEY TAKEAWAYS

Power is real-time and precise; heart rate lags by 30–90 seconds and varies with conditions.
High heart rate at your normal FTP target is a warning signal — illness, fatigue, or heat — not a target to ignore.
Heart rate is the better tool for very easy zone 2 where keeping genuinely easy matters most.
RPE alongside either metric gives the most complete picture of daily readiness.

WHO THIS IS FOR

IS THIS YOU?

The power meter owner who ignores heart rate

You train purely to power and occasionally wonder why sessions feel much harder than the numbers suggest.

The heart rate user considering a power meter

You want to understand what power training adds before making the investment.

THE ROADMAN VIEW

Power meters changed training feedback fundamentally — the data is real-time, objective, and immune to the noise that makes heart rate tricky. But the riders who get the most from power data are the ones who also pay attention to heart rate, because HR tells you something power cannot: how much the effort is costing your body today. If your 100% FTP intervals are running at 95% of your max HR when they normally sit at 88%, that's your body flagging something. Ignore it and you're training into fatigue.

Professor Seiler makes an interesting point about zone 2 specifically: HR may actually be the better marker for genuinely easy aerobic riding, because the precision of power matters less and HR gives you a direct physiological signal of how easy the session really is. Power in zone 2 that sits slightly too high produces the exact grey-zone drift he identifies as the most common amateur training problem. Some riders find it easier to stay genuinely easy by looking at heart rate rather than hitting a watt target.

Anthony's practical experience after testing both: use power to prescribe and execute hard sessions, use heart rate as a daily readiness check and zone 2 governor. When power and HR diverge significantly from your baseline — higher HR for the same power than usual — that's a day to back off regardless of what the schedule says.

EXPERT EVIDENCE

WHAT THE EXPERTS SAY

Professor Stephen SeilerExercise physiologist, University of Agder; polarised-training researcher
Heart rate remains a valuable training metric, particularly for monitoring the physiological cost of effort rather than just the mechanical output. The combination of power and heart rate — watching how the two interact over a session and across weeks — gives a richer picture than either metric alone.
Hear it: Secret To Cycling Fast At A Low Heart Rate | Prof Seiler
Joe FrielAuthor of The Cyclist's Training Bible; co-founder of TrainingPeaks
Cyclists who have both power and heart rate should use power as the primary prescription tool and heart rate as a secondary check. A rising decoupling between power and HR across a long session, or a persistently elevated HR at a given power compared to baseline, are actionable signals that power alone doesn't provide.
Hear it: Joe Friel's Cycling Training Plan Structure | Roadman Cycling

PRACTICAL APPLICATION

DO THIS WEEK

Set a morning resting HR baseline and track it weekly
Take your resting HR each morning before getting up. Track it over weeks. A resting HR 5–8 bpm above your 7-day average is a reliable signal of accumulated fatigue or early illness — consider replacing a hard session with easy riding that day.
Use heart rate to govern zone 2, power to govern threshold
For easy rides, keep HR under 75% of max — regardless of what power zone that puts you in. For threshold sessions, use power to hold 95–105% FTP and check HR isn't running anomalously high. Each metric governs the zone it is most reliable for.
Check the power-HR decoupling on long rides
In a 3-hour zone 2 ride, your HR should hold relatively steady as power stays constant. If HR drifts up 10+ bpm over the final hour at the same power (cardiac drift), your aerobic base needs more easy volume or you started the ride dehydrated. TrainingPeaks' Pw:HR metric tracks this automatically.

COMMON MISTAKES

WHAT CYCLISTS GET WRONG

MISTAKEIgnoring HR and pacing solely to power when HR is clearly elevated.
FIXHigh HR at your normal training power means the effort is costing more than usual. Reduce power to keep HR at its normal range — don't fight your body to hit a number.
MISTAKEAbandoning HR entirely because you now have a power meter.
FIXHR is free data that power cannot fully replace. Use both. The interaction between them is often where the most useful training insights live.
MISTAKEUsing a maximum heart rate formula instead of testing actual max HR.
FIX220 minus age is population-level guessing. Find your real max HR through a genuine maximal effort. Using a wrong max HR invalidates your entire HR zone structure.

FAQ

FREQUENTLY ASKED QUESTIONS

Is power or heart rate better for zone 2 training?

Heart rate is often more reliable for zone 2, because the primary goal is keeping the effort physiologically easy — and HR directly measures that. Power in zone 2 can feel very different on a hot day versus a cool one; HR adjusts for those conditions automatically.

What is cardiac decoupling and why does it matter?

Cardiac decoupling is the gradual rise of heart rate relative to power over a long ride. It indicates that your cardiovascular system is working harder to maintain the same output — a sign of fatigue, heat, or aerobic base limitations. High decoupling suggests your aerobic base needs more time before adding intensity.

Can I use heart rate for threshold intervals without power?

Yes. Threshold HR is roughly 90–95% of your max HR. Target this range for 2×20 interval sessions. It's less precise than power — HR lags by up to 90 seconds at the start of each interval — but produces effective threshold training.

Does caffeine affect training with heart rate?

Yes. Caffeine typically raises resting and exercise HR by 3–8 bpm. If you train after a coffee, your HR zones need mental adjustment upward, or you risk training below your intended zone by chasing a number calibrated without caffeine.

Is HRV better than resting HR for training decisions?

HRV (heart rate variability) is more sensitive than resting HR for detecting accumulated fatigue. Apps like HRV4Training or the Whoop band track it automatically. But daily resting HR is a free, accessible alternative with most of the practical value for decision-making.

RELATED EPISODES

HEAR THE CONVERSATIONS

Secret To Cycling Fast At A Low Heart Rate | Prof Seiler

Joe Friel's Cycling Training Plan Structure | Roadman Cycling

80/20 Training to Ride Faster | Dr Stephen Seiler