REF-1431 · Carey et al., 2009 · Journal of Strength and Conditioning Research · Paper · PubMed

Can I use my bike heart-rate zones for running?

Not reliably: in 16 triathletes threshold heart rate averaged only 3 bpm apart (154 bike, 157 run), but the individual error was 12 bpm. Test each sport, or use RPE. Abstract.

Main caveat: Abstract only; no limits of agreement, no individual data, no definition of "total error".
limited evidenceMeasured on trained to highly trained athletes

Carey and colleagues (University of St Thomas, Minnesota) asked whether measurements from one mode of testing can be used to prescribe training in another, as when heart-rate zones from a cycling test are used for running. Sixteen experienced triathletes did VO2max tests on a cycle ergometer and a treadmill and a 30-min time trial on the cycle ergometer.

On average the two modes gave the same VO2max (68.4 ± 11.1 vs 69.0 ± 13.2 mL/kg/min), maximal heart rate (177.1 ± 6.1 vs 178.1 ± 7.4 bpm) and anaerobic-threshold heart rate (153.9 ± 10.5 vs 157.0 ± 9.5 bpm).

But the threshold heart rates of the two modes correlated weakly (r = 0.321), so although the mean gap was 3.1 bpm, the total error was 12.1 bpm — "limited practical application of training zones between modes".

In the time trial, heart rate (159.4 ± 8.9 vs 153.9 ± 10.5 bpm) and respiratory rate (37.8 ± 6.0 vs 32.4 ± 3.2 breaths/min) ran above their threshold values through drift, while power was not different from threshold power (249.1 ± 47.8 vs 240.6 ± 71.1 W).

The respiratory-rate breakpoint gave a threshold heart rate of 158.4 ± 10.0 bpm against 153.9 ± 10.5 from VE/VO2, a total error of 9.0 bpm. The authors recommend sport-specific testing and power rather than heart rate or breathing rate for steady efforts.

Our reading: this is the base's same-athlete answer to "can I use my bike zones for running?" — no, not because the average is far off, but because one athlete's gap can be large in either direction.

Protocol

Participants: n = 16 experienced triathletes (women and men by PubMed indexing; numbers, age and training volume not in the abstract).
Tests: VO2max on a cycle ergometer (CE) and a treadmill (TM); anaerobic threshold (AT) from the ventilatory equivalent for oxygen (VE/VO2) and from the respiratory-rate (RR) breakpoint; a 30-min time trial on the CE.
Agreement: mean difference, correlation coefficient and total error (TE) between modes and methods; the abstract does not define TE or give limits of agreement.
Funding and interests: none listed in the PubMed or Crossref record; no conflict statement in the abstract record.

Key Results

MeasureCycle ergometerTreadmillAgreement
VO2max (mL/kg/min)68.4 ± 11.169.0 ± 13.2not significantly different
HRmax (bpm)177.1 ± 6.1178.1 ± 7.4not significantly different
AT heart rate, VE/VO2 (bpm)153.9 ± 10.5157.0 ± 9.5mean difference 3.1; r = 0.321; total error 12.1
30-min cycling time trial vs cycling ATTime trialAT
Heart rate (bpm)159.4 ± 8.9153.9 ± 10.5 (significantly lower)
Respiratory rate (breaths/min)37.8 ± 6.032.4 ± 3.2 (significantly lower)
Power (W)249.1 ± 47.8240.6 ± 71.1 (not different)
Threshold method: AT heart rate from the respiratory-rate breakpoint 158.4 ± 10.0 vs 153.9 ± 10.5 bpm from VE/VO2, significantly different, total error 9.0 bpm.
Individual error (our arithmetic, not in the abstract): if "total error" is the root-mean-square difference between modes, the SD of the differences is about 11.7 bpm and the 95% limits of agreement would put one athlete's running threshold heart rate anywhere from about 20 bpm below to 26 bpm above their cycling one. The abstract gives no limits of agreement.

Mechanisms

Measured: similar group means for VO2max, HRmax and threshold heart rate across modes, with weak within-athlete agreement for threshold heart rate; upward drift of heart rate and breathing rate during a steady 30-min effort at about threshold power.
Authors' interpretation: zones from one mode should not be applied to the other; incremental tests underestimate steady-state heart rate and breathing rate because both drift, so power is the better guide for steady efforts.
Inference: group means range from 3 bpm to more than 10 bpm between modes, for reasons these studies do not show (the base's other same-athlete numbers: 10 bpm lower on the bike at MLSS in moderately trained men, REF-1432; HR at VT 145 vs 156 bpm in highly trained triathletes, REF-537). A fixed offset fits the average athlete, not the one asking.

Practical Application

Can I use my bike heart-rate zones for running? Not reliably: in 16 triathletes threshold heart rate averaged only 3 bpm apart (154 bike, 157 run), but the individual error was 12 bpm. Test each sport, or use RPE. Abstract.
How much lower is heart rate on the bike? At maximum these triathletes differed by 1 bpm and at threshold by 3 bpm on average; SYNTH-38 passes on Olympiatoppen's "~5% higher running" (about 9 bpm at an HRmax near 180, our arithmetic), while REF-537's review reports cycling HRmax "often" 6-10 bpm lower in triathletes, so the size varies between studies and athletes. Treat any offset as a range with a wide individual spread, not a rule.
Steady efforts: heart rate drifted above threshold heart rate (159.4 vs 153.9 bpm) in a 30-min ride at about threshold power; for threshold work on the bike, power (or RPE) is the steadier guide (PHYS-12).
What it does not show: single-sport athletes, field tests, zones below threshold, or water and swimming (REF-1433, REF-1441).

Limitations

Abstract only; no limits of agreement, no individual data, no definition of "total error".
Triathletes who train both modes; sex split, age and training history not in the abstract.
Laboratory threshold from ventilatory breakpoints; field-derived thresholds were not studied.
Cycling only for the steady-state time trial; no running time trial.
Small sample (n = 16); the correlation of 0.321 has a wide uncertainty.
Funding and interests: not stated in the record.
How this entry was checked and changed
Why this level

(from the abstract) — a test-transfer study of 16 (the rubric's B for test validation studies); the sex split, test order and the definition of "total error" are not in the abstract