Stroke Rate and Power: The Trade-Off Is Not About Efficiency

The question behind the question

A rower finishes a piece, looks at the monitor, and sees a number: 500-metre split, stroke rate, watts. The natural next thought is that the machine has just explained the performance. It has not. It has reported three derived quantities, and the relationship between them is where most of the confusion about rate comes from.

The specific confusion worth naming is this. Raise your stroke rate, and your watts go up. The usual inference is that you have become more efficient, that the faster cadence is somehow extracting more from each stroke. That inference is not supported, and it is not a small error, because it changes what you should do next. If rate made you more efficient, you would want to raise it whenever you could. If it does not, then raising it always costs something, and the only question is whether the thing you bought with the watts is worth the thing you paid.

Before any of that, it is worth being clear about what the rate is for, since the manufacturer sets this out plainly: stroke rate is a descriptor of cadence, reported by the monitor stroke by stroke, and its use is to describe or to constrain a target rather than to be improved in itself ([46] Concept2).

This article works through what the measured literature actually supports about that exchange, and it is more specific than the usual advice in both directions. There is a real, well-measured effect of stroke rate on power, and it is not an efficiency effect. There is a real cost, and it shows up in technique rather than in the energy ledger. And there is a defensible way to pick a rate for a given piece, which follows from the physiology rather than from habit.

What the arithmetic actually says

The relationship everyone starts from is the right one: power equals stroke rate multiplied by work per stroke. One stroke is one drive plus one recovery, and the rate counts both halves. This is genuinely all the arithmetic, and it is enough to explain the most common observation about rate, which is that at a fixed effort, raising the rate usually lowers the work available in each individual stroke.

What the arithmetic cannot do is tell you anything about efficiency, because efficiency is not in the equation. Two rowers can produce identical average watts at completely different rates, and the equation is satisfied in both cases. The two strokes are not equivalent, and the difference between them is where the interesting content of this article lives.

It is worth being precise about the units, because the units are where the confusion usually starts. Power is watts. The split is the time to cover 500 metres at the current average power ([50] Concept2), so faster splits mean more watts, and the two are inversely related. Most rate guidance is actually a statement about a split, expressed in a different variable, and the conversion between them is a piece of arithmetic that the manufacturer publishes precisely because it is not obvious ([57] Concept2). The watts figures quoted throughout this article come from that same conversion ([58] Concept2). The unit a rower thinks in is the split; the unit the rower is being advised in is the rate. Those are not the same question.

What stroke rate changes: the distribution of power inside the stroke

The most useful piece of research on this question is Hofmijster's 2007 power-flow analysis, because it does something the simple arithmetic cannot: it decomposes the stroke rather than summarising it ([1] Hofmijster et al.). The approach treats the handle as a point whose velocity changes over the drive, and partitions the mechanical work into a propelling fraction, where the rower is doing useful work against the flywheel, a compensating fraction, where the rower is absorbing energy back out of the flywheel, and a lost fraction, which is energy gone into rotating the handle and the chain.

The finding that matters here is subtle. As stroke rate rises, the propelling fraction of the stroke does not grow in proportion to the total. The rate changes when the power is delivered across the stroke and how the three fractions are weighted, not simply how much of each there is. The consequence for a rower is that raising your rate does not deliver a uniformly larger push. It redistributes the push, and the redistribution is not free — the part of the stroke where you are decelerating the handle becomes a smaller fraction of a faster cycle, which is precisely the phase where a rushed rower starts losing the handle.

This is also why "row longer and harder" and "row shorter and faster" are not interchangeable routes to the same place. Baudouin and Hawkins' biomechanical review lays out the underlying determinants of a rowing stroke, and the takeaway is that the stroke has a structure that a given rate and a given load can exploit differently ([3] Baudouin and Hawkins). The force you can apply, how long you can keep it applied, and how quickly the handle can be turned around are three separate things, and a rate target moves the last one without touching the others.

Held and colleagues tested this directly, varying stroke rate and gearing to see how mechanical power output responds ([4] Held et al.). Their contribution is to show that rate and gearing are genuinely independent levers on the ergometer, which matters for the next section: you can change how hard each stroke feels without changing how often you do it, and vice versa.

What stroke rate does not change: efficiency

Here is the result the rest of the article depends on. Hofmijster, Van Soest and De Koning measured gross efficiency during ergometer rowing across a range of stroke rates, and found it was not affected by stroke rate ([2] Hofmijster et al.). Gross efficiency here is mechanical work output divided by metabolic input, and it held at roughly eighteen to twenty percent across the rates tested.

This is a null result, and null results are easy to overlook, which is part of why it has been so widely misreported. Its force comes from what it rules out. If efficiency rose with rate, then faster rowing would be doubly good: more strokes and better conversion. It does not. The denominator moves with the numerator. A faster rower burns proportionally more energy to produce the same ratio of work to effort, which is the definition of a higher absolute cost at the same efficiency.

For a rower the practical consequence is precise. If you want more watts, you can get them by raising the rate, and you will pay for them in energy expenditure. You cannot get them by becoming more efficient, because efficiency is not available as a variable at a different rate. Anything that seems to suggest otherwise — a piece that goes faster, an interval that feels smoother — is showing you a different stroke at a different intensity, not a more efficient one.

The metabolic cost, and why duration decides

If efficiency is flat and absolute cost rises, the question becomes how large the cost is and when it becomes unaffordable. This is where duration enters, and it is why a single rate recommendation cannot be correct for all rowing.

The mechanism is the fatigue-threshold account of critical power, which treats the difference between your maximal sustainable power and the power you are currently producing as a finite fatigue budget that depletes at a rate proportional to how hard you are working ([28] Poole et al.). Raise your rate and you raise power, so you raise the depletion rate. For a two-minute piece the budget does not have time to matter. For a ninety-minute piece it is the whole story, and a rate that is sustainable for two minutes may be unsustainable for ninety.

The energy-system framing says the same thing more slowly. During a maximal effort, aerobic and anaerobic contribution both matter and their relative weight depends on how long the effort lasts ([27] Gastin). A short maximal piece is dominated by systems you cannot train away within the piece; a long piece is dominated by oxidative supply, which is exactly the supply that scales with duration rather than with rate.

The racing data make the practical version concrete. Ingham and colleagues analysed the determinants of 2000 m ergometer performance in elite rowers and found that the strongest determinants are physiological capacities, not technique variables ([22] Ingham et al.). A rower who raises the rate on a long aerobic piece is spending a physiological reserve that was not the limiting factor, in order to buy something that was not the constraint.

The 1500 m comparison makes the duration-dependence explicit. Astridge and colleagues compared energetic contribution and pacing between maximal 2000 m and 1500 m efforts, and the two distances do not want the same distribution of effort ([25] Astridge et al.). Their companion analysis of the power profiles behind those distances points the same way ([26] Astridge et al.). If a single rate were optimal for both, the pacing profiles would match; they do not.

Higgins and Hofmijster make the same argument for the shortest of these distances, showing how duration changes the energy budget in the shift from 2000 m to 1500 m ([42] Higgins and Hofmijster). This is the current state of the question from the group whose work underlies most of the rest of this article, and it is worth noting that the mechanism is still being actively refined rather than settled.

Concept2 makes the practical version of this case directly, arguing for lower rates in longer pieces and framing rate as something to be chosen for the duration of the work rather than maximised ([48] Concept2). That is the correct reading of the physiology, and it is close to the opposite of the folk advice that a higher rate is always a better rate.

The cost the usual advice omits: technique degrades with rate

Here is the part of the story that the efficiency argument alone does not reach, and it is the strongest practical reason to be careful with rate.

Duchene and colleagues measured performance, technique and core stability across stroke rates on the ergometer, and found that the rate influences technique and core stability, not just output ([5] Duchene et al.). That is the finding that turns rate from a free dial into a trade-off. Ettema and colleagues separated the effect of rate from the effect of intensity, which is the necessary methodological step: if technique only degrades when you go fast and hard, then a rate increase within a submaximal piece is harmless ([6] Ettema et al.). It is not harmless.

The mechanism shows up at every level of the body. Pakravan and colleagues found that lower-limb intra-joint coordination becomes more variable as stroke rate rises, in experienced and novice rowers alike ([7] Pakravan et al.). More variable coordination is a less repeatable stroke, and a less repeatable stroke is a stroke whose peak force varies from one attempt to the next — which means the watts you saw last time are not the watts you will get this time.

Gao and colleagues approached the same question by treating the whole stroke as a signal and measuring how regular it becomes, finding that technique becomes less regular as rate climbs ([9] Gao et al.). Engstrom and colleagues showed that rate effects compound with equipment setup, so the same rate is not the same stroke on two machines set up differently ([8] Engstrom et al.). Penichet-Tomas and colleagues compared classic sweep mechanics with conventional ergometer technique across rates, which is a useful corrective if you learned your stroke in a boat and now spend your time on a machine ([10] Penichet-Tomas et al.).

The upper body tells the same story. Giustino and Zangla measured cervical spine kinematics across stroke rates and found they shift with rate ([11] Giustino and Zangla), which is directly relevant to the neck and upper-back complaints that rowers report when they push their rate. Li and colleagues documented what elite trunk and shoulder kinematics actually look like ([12] Li et al.), and that is the honest benchmark: a rate target is an approximation of an elite movement, and the closer you push to the rate, the closer you need your trunk to be to that benchmark.

There is a constructive side to all this. Simon and colleagues showed that technical and core stability parameters predict ergometer performance, which means the technique that degrades at high rate is also the technique worth training ([32] Simon et al.). Legge and colleagues frame movement competency as the thing that makes a stroke effective, rather than something that emerges from going faster ([44] Legge and colleagues). And van Nieuwburg and colleagues demonstrated a performance gain from adjusting blade geometry rather than simply raising the rate ([45] van Nieuwburg et al.), which is the alternative when the rate dial is already as high as your technique can support.

The asymmetry case matters here too. Buckeridge and colleagues found left-right kinematic asymmetries on the ergometer ([31] Buckeridge et al.), and a rate increase under fatigue is when asymmetry tends to express itself. If your rate target depends on a specific sequencing that only holds when you are fresh, the target is conditional on freshness, and conditioning a training plan on that is worth stating explicitly.

Rate in a crew is a group decision

Everything above is about a single rower on a machine. On the water, the rate is not yours to set.

de Brouwer and colleagues showed how coordination between rowers in a crew affects the boat, and Cuijpers and colleagues tracked how that coordination changes as stroke rates rise ([35] de Brouwer et al.; [36] Cuijpers et al.). The finding that matters for coaching is that coordination degrades with rate in the same way technique does, so a crew's sustainable rate is bounded by its least consistent rower, not its best.

Holt and colleagues documented the technical determinants of on-water rowing performance, and they are not the same as the ergometer's ([33] Holt et al.). Lamb's foundational comparison of ergometer and on-water kinematics remains the cleanest statement of the gap ([34] Lamb): a rate that is comfortable on the erg is not automatically comfortable in the boat, because the boat asks you to do the same thing on an unstable platform. Ergometer rate targets are a training tool, and they transfer to the water as a range rather than a number.

The damper is a different dial, and this is the most common mix-up

If you take one thing from this article, take this. The damper setting and the stroke rate are independent variables, and the number everyone quotes — "high damper for strong, low damper for fast" — conflates them.

The damper controls how much air the flywheel has to push through, which sets the resistance each stroke has to work against. The rate controls how often you do that work. The manufacturer's own guidance is explicit that damper setting, stroke rate and intensity are three separate things, and it publishes an article specifically to debunk the conflation ([47] Concept2). It also explains what the lever physically does ([53] Concept2), and gives practical setting guidance framed correctly as an intensity control ([49] Concept2).

The experimental literature agrees and adds a warning. Kane and Jensen measured the effect of drag factor on physiological aspects of rowing directly, and found effects that are not simply a function of the effort you feel ([15] Kane and Jensen). Kane and Mackenzie showed that stroke resistance affects rowing economy in trained club rowers after a season, which means the setting you finish a season on is not a neutral choice ([16] Kane and Mackenzie).

Vogler and Rice compared physiological responses across different models of the Concept II ergometer, which is the right way to answer a question about whether the machine's specification is trustworthy ([17] Vogler and Rice). Lu and colleagues did the same comparison between ergometer types more recently, and found they are not interchangeable for physiological purposes ([38] Lu and colleagues). If you moved machines, or if you compare a rate on a Concept2 with a rate on something else, that is a comparison across two different experiments.

Kane and Jensen's paper is also the reason to distrust the intuition that a high damper is a beginner crutch. Concept2's own account of what Olympians set is a useful corrective to that ([51] Concept2) — elites tend to row in a middle-to-high range, because the damper is an intensity control and elite rowing is high intensity.

Why the rate is not a pure power question: force-velocity

There is a reason rate and load are not interchangeable, and it is the force-velocity relationship. Sprague and Martin characterised force-velocity and power-velocity behaviour during maximal short-term rowing ergometry, and the standard shape of that relationship applies in rowing as it does elsewhere: heavier loads produce more force and less velocity, lighter loads produce less force and more velocity ([19] Sprague and Martin).

This is the physiological reason the damper and the rate are separate dials, viewed from the other end. If you want more force, you can raise the rate so that each stroke is lighter, or you can raise the damper so that each stroke is heavier, or both. Those are different interventions with different physiological costs, and the force-velocity profile says the difference is real rather than notional.

Nordez and colleagues measured force-velocity and power-velocity relationships in on-water rowing, and the on-water relationship is not identical to the ergometer one ([20] Nordez et al.) — another reason the ergometer is a training tool rather than a simulator. Jacobs and Schumann found that individual load-velocity characteristics are associated with 2000 m performance, which is the modern and more useful version of this question: rather than prescribing everyone the same rate, measure what your own profile does ([21] Jacobs and Schumann). Kleshnev's current modelling of blade efficiency is a further reminder that the machine a rower is on determines what the numbers mean ([43] Kleshnev).

What the monitor can and cannot tell you

The PM5 is a genuinely good piece of engineering, and it is worth knowing what it computes, because a lot of confident interpretation of monitor fields is really interpretation of the monitor's internal model.

Concept2's technical description of the monitor is the authoritative source: it explains what the PM5 computes and how the displayed fields relate to one another ([52] Concept2). The force-curve display is the most direct view of how power is distributed through a stroke ([55] Concept2), and it is the field that makes the distribution argument from the first section visible to a rower rather than merely asserted. The list of available monitor fields is short and worth knowing before attempting analysis ([54] Concept2).

The limits are worth stating plainly. Hofmijster and colleagues showed that mechanical power output in rowing should not be determined from oar forces and oar motion alone ([13] Hofmijster et al.), which is a direct warning against inferring power from handle force data alone. Hofmijster and colleagues also showed that the same nominal stroke produces different power depending on the rower's skill, because skilled rowers lose less of the stroke ([14] Hofmijster et al.). The practical implication is that a stroke rate is not a prescription: "row at 30" means different things for a rower whose 30 is clean and a rower whose 30 is a rush.

Mentz and colleagues built an independent test rig for wind-braked ergometers and validated it, which is the right reference point for anyone treating monitor-derived power as a measurement rather than an estimate ([37] Mentz et al.). Borges and Veiga's systematic review of how ergometer performance is evaluated is worth reading if you want to know where the field's methods disagree with each other ([18] Borges and Veiga). Cerne and colleagues provide the reference point for what distinguishes skilled from untrained rowing in the kinematic and kinetic numbers ([30] Cerne et al.), which is what any rate target is implicitly approximating.

Choosing a rate: a decision procedure

Everything above reduces to something you can actually do.

Start from the split, not the rate. Rate advice is usually expressed in the wrong unit. The unit you care about is a 500 m split, and the conversion between split, watts and rate is published arithmetic you can do once and then stop thinking about ([57] Concept2). Concept2's own route from a recent benchmark to a training pace is the version of this that most people should start from ([56] Concept2).

Pick rate from duration, using the direction of the evidence. Long aerobic work wants a lower rate; short maximal work tolerates and benefits from a higher one ([48] Concept2). This is not a style preference, it follows from the fact that efficiency does not change with rate while metabolic cost does ([2] Hofmijster et al.), and from how duration changes which energy system is limiting ([27] Gastin; [28] Poole et al.; [42] Higgins and Hofmijster).

For a maximal 2K, treat rate as a pacing instrument, not a target. The determinants of 2K performance are physiological ([22] Ingham et al.), so the rate decisions that matter are the ones that keep you on an even split when you want to go out fast. Consistency of pacing and metabolic response across repeated attempts is measurable ([23] Gee et al.), and pacing strategy has documented effects on physiological and kinetic variables, not just on finish time ([24] Dimakopoulou et al.). The energy-flow model that most fast-start advice descends from is de Koning's ([29] de Koning et al.).

Test the rate you intend to use, not a comfortable one. Technique quality is rate-dependent ([5] Duchene et al.; [6] Ettema et al.), coordination gets more variable as rate climbs ([7] Pakravan et al.; [9] Gao et al.), and your neck and trunk have opinions about it too ([11] Giustino and Zangla; [12] Li et al.). If the target rate is only achievable when fresh, plan around that rather than discovering it in a race.

Change the load before you change the rate. If you need more watts and you are already at the top of the rate range your technique supports, the damper and the equipment are the remaining levers ([15] Kane and Jensen; [45] van Nieuwburg et al.). Rowing harder per stroke is not the same intervention as rowing more often, and the force-velocity relationship says so ([19] Sprague and Martin).

Know what actually predicts your 2K, because it is probably not cadence. It is aerobic capacity, short maximal power, and technical consistency ([39] Cerasola et al.; [40] Lanigan et al.; [41] DeLeo et al.). If you are deciding where to spend limited training time, this is the evidence to spend it on.

What is still unsettled

Three things are genuinely open, and it is worth knowing which claims in this article are firm and which are provisional.

The mechanism by which rate degrades technique is well established as an observation and less well established as a model. We can say with confidence that technique quality is rate-dependent and worsens as rate climbs ([5] Duchene et al.; [7] Pakravan et al.; [9] Gao et al.). We can say less confidently where in the stroke the loss occurs and whether it is recoverable with training. The constructive work on technical and core stability predictors ([32] Simon et al.) and on movement competency ([44] Legge et al.) points at the answer without having arrived at it.

Ergometer-to-water transfer is bounded and the bounds are not well mapped. Lamb established the gap decades ago ([34] Lamb); Holt documented that boat technique has its own determinants ([33] Holt et al.); Nordez found on-water force-velocity differs from ergometer force-velocity ([20] Nordez et al.). What remains open is a quantitative rule for translating an ergometer rate target into a boat one.

And the duration question keeps moving, because the race distances themselves are moving. The 1500 m analysis ([42] Higgins and Hofmijster) and the 2000-versus-1500 comparisons ([25] Astridge et al.; [26] Astridge et al.) are recent enough that the practical guidance has not fully caught up with the physiology.

One thing that is not open: the efficiency result. Gross efficiency on the ergometer does not move with stroke rate ([2] Hofmijster et al.), and that finding is old enough, replicated enough, and specific enough to be treated as settled. It is also, in my reading, the most useful thing in this article, because it removes the main reason people think a higher rate is a better rate.

What to do tomorrow

Pick your next steady piece and count your rate. Then look up what the equivalent on-water rate would be, using a crew video rather than a guess. The gap between the two is the most useful thing most rowers can learn this week.

Then, on a 20-minute piece, hold the split and drop the rate by three. If the piece gets harder rather than easier at the same split, your rate was doing work your technique was paying for, and now it is not. That single comparison is the most direct test of the argument in this article, and it costs you one session.