Do heart-rate zones transfer between running, rowing, cycling and the SkiErg?

Heart-rate zones are usually calculated from one maximum heart rate, which typically comes from an age formula or from a hard effort on one particular machine, often a run. The same zones then get applied on the rower, the bike and the SkiErg. They transfer reasonably well, but not perfectly. Studies comparing exercise modes find that most people reach a slightly lower maximum heart rate when rowing, cycling or using a ski ergometer than when running, and that heart rate at a given metabolic intensity is also slightly lower on the rower. The typical gap is about 4 to 7 beats per minute on average, which is small, but large enough to move a reading across a zone boundary.

Why the same effort produces a different heart rate

Heart rate is one part of cardiac output, the volume of blood the heart pumps each minute. Cardiac output equals heart rate multiplied by stroke volume, the amount of blood ejected with each beat. When stroke volume is larger, the heart can deliver the same blood flow at a lower rate.

Body position and the muscles involved both influence stroke volume. In a 2002 study of 55 healthy young men, Yoshiga and Higuchi compared progressive tests on a rowing ergometer and a treadmill. Rowing produced a lower heart rate at every matched blood-lactate level and a lower maximum, even though maximal oxygen uptake was slightly higher on the rower. The authors' explanation is that the seated position and the larger working muscle mass of rowing help blood return to the heart, so each beat moves more blood. The study measured oxygen pulse, a proxy for stroke volume, not stroke volume itself.

A second factor is familiarity. A maximal test only reaches a true cardiovascular maximum if the heart and lungs, rather than local muscle fatigue or poor technique, are what end the effort. On an unfamiliar machine, the arms or legs can give out first, and the recorded peak is lower.

How large the differences are

The rowing study also showed the gap below maximum: at a blood lactate of 4 mmol/L, a common reference point for hard sustained work, heart rate was 170 bpm on the rower and 177 on the treadmill.

The SkiErg comparison by Nelson and colleagues found that peak oxygen uptake, time to exhaustion and maximal perceived exertion were all lower on the ski ergometer. This fits the familiarity explanation, although the study did not test why the values differed. It included only women of average fitness, so the size of the gap may not apply to trained hybrid athletes.

For cycling, a 2009 review by Millet, Vleck and Bentley concluded that heart rate differs between cycling and running at both maximal and submaximal intensities, and that maximal oxygen uptake is specific to the mode a person trains in: runners usually score higher on a treadmill, while cyclists and triathletes score similarly on both. Basset and Boulay tested trained runners, cyclists and triathletes on both machines and found that heart rate at a given percentage of each mode's own maximal oxygen uptake was closely related between tests. Their conclusion was that one test can supply reference heart rates for both activities in trained endurance athletes. The sample was small, and the result may not hold for people with little cycling experience.

All of these figures are group averages. In the rowing study, individual values were spread by roughly 10 bpm on either side of the mean, and none of the studies reports how much each person's own gap varied. One athlete's difference between machines can be smaller or larger than the average.

A worked example on five zones

Pulz8 uses five zones based on percentage of maximum heart rate: below 60% is Zone 1, then 60–69%, 70–79%, 80–89%, and 90% and above for Zone 5. As an illustration, take a stored maximum of 190 bpm from running, and assume this person's true peaks are 186 on the rower and 183 on the SkiErg, in line with the average gaps above. The table shows the heart rate at the same relative effort on each machine and how the board classifies it against the stored 190:

In the middle of a zone the difference changes nothing. Near a boundary, the same relative effort on the rower or SkiErg shows one colour lower than it would on the run. An effort at 90% of SkiErg maximum appears orange rather than red.

This is an example, not a correction factor. The individual gap could be smaller, larger or absent, and percentage-based zones are themselves an approximation. A review of intensity prescription methods by Mann and colleagues notes that the same percentage of maximum heart rate can place different people above or below their metabolic thresholds. A zone colour is a useful label for heart rate, not a measurement of lactate or of how close someone is to their limit.

Using one zone set across several machines

A mixed class that moves between running, rowing and the SkiErg can still use one set of zones, provided everyone knows the likely direction of the error. On the live board, a member who reads orange on the SkiErg while breathing as hard as they do in red on the run is most likely seeing this mode effect, not a failure to work hard enough. Perceived effort, breathing, pace or wattage, and the stated goal of the station should carry more weight than an exact colour target.

The stored maximum matters more than any adjustment. If it comes from an age formula, the formula's error is often larger than the mode effect. If it comes from a recorded hard effort, it helps to know which machine produced it. A maximum recorded on the rower and then applied to running will push running readings slightly higher, into the next zone near boundaries.

For athletes who train mostly on one machine, setting the maximum from that machine gives the most accurate colours where they spend most of their time. Recording the highest credible reading on each machine during normal hard sessions builds a clearer picture without adding extra all-out tests.

Key points

1. Note which machine produced the stored maximum, because that is the mode where the zones fit best.
2. Expect slightly lower readings on the rower, bike and SkiErg than on the run, typically a few beats per minute, with wide individual variation.
3. Read colours near a boundary with care, since a mode difference of 4 to 7 bpm can shift a reading by one zone.
4. Coach by effort and output alongside heart rate when stations switch between machines, rather than asking for the same colour everywhere.
5. Collect peak readings per machine during regular sessions before deciding whether the stored maximum needs to change.

Sources

• Yoshiga CC, Higuchi M. Heart rate is lower during ergometer rowing than during treadmill running. European Journal of Applied Physiology, 2002.
• Nelson H et al. Comparison of peak aerobic capacity between the treadmill and a skiing ergometer. Journal of Exercise and Nutrition, 2021.
• Millet GP, Vleck VE, Bentley DJ. Physiological differences between cycling and running: lessons from triathletes. Sports Medicine, 2009.
• Basset FA, Boulay MR. Specificity of treadmill and cycle ergometer tests in triathletes, runners and cyclists. European Journal of Applied Physiology, 2000.
• Mann T, Lamberts RP, Lambert MI. Methods of prescribing relative exercise intensity: physiological and practical considerations. Sports Medicine, 2013.

Heart rate is a training signal, not medical advice. The examples above illustrate general principles rather than an individual training prescription.