At the end of a training session, after a hundred or so arrows, every archer wonders at some point whether the last ends are worth as much as the first. The shoulder starts to make itself felt, aiming seems to take longer, and the number that goes round every club is exactly that one: beyond a hundred arrows you are shooting tired. The question I am asked most often has two parts, and they are best kept apart. The first is from which arrow fatigue sets in; the second is whether that fatigue shows in the score.
Studies have measured four different things: the shoulder muscles, the sway of the bow while aiming, the tiredness archers report and the score. What makes the picture interesting is that the four do not move together. Signs of fatigue turn up in the body and in the bow, though less cleanly than people tend to say, while in trained archers a consistent drop in score has not been seen so far. At the end of the article the section "How we came to know it" lists the studies year by year; here I start from the results and from how firm they are.
What it costs to hold the bow at full draw
To see where fatigue comes from, it helps to start with the effort of a single shot. The only direct measurement comes from seven university archers who held the shooting position until exhaustion: according to the authors the effort corresponded to about 40 to 50% of maximal push-pull force, measured on an ergometer, and the hold lasted 52 seconds on average. In all seven the electrical signal of the posterior deltoid slid towards lower frequencies, by 0.72% a second on average, which is the classic way electromyography records a muscle that is tiring. The registry classes as reported the claim that holding the shooting position demands between 40 and 50% of maximal force, because there is a single small sample and the way the share was worked out is not described in detail.
That figure also has to be read for what it does not say. A shot lasts a few seconds, not a minute, so a hold to exhaustion measures the reserve rather than the cost of a single arrow. In four elite archers, moreover, electromyography of the posterior deltoid in the second before the clicker reaches 84 to 87% of the maximal signal, although that is the amplitude of an electrical signal and not a force. Taken together, the two results say that on every arrow some shoulder muscles work for a few seconds at a high share of their capacity, and this is where the idea comes from that a long session, adding up many short holds, ends up tiring the shoulder.
A hundred arrows and the shoulder
The shoulder has been measured at a hundred arrows only recently, and in a single group. Twenty Polish club archers who shoot traditional bows were followed with electromyography of six shoulder muscles at rest, after fifty and after a hundred arrows. Between the fiftieth and the hundredth arrow, the string-arm infraspinatus falls both in amplitude, from 162.0 to 113.2 microvolts, and in median frequency, from 60.7 to 49.3 hertz, and the lower trapezius produces a lower peak. At the same time the deltoids and the upper trapezius raise their activation, which is how the body compensates for a muscle that is delivering less.
The picture is not uniform, though. In the three parts of the trapezius and in the middle deltoid the frequency does not change, and in the posterior deltoid it rises, which runs opposite to fatigue; the article's abstract reports a decline after a hundred arrows, but in the tables the decline is in two muscles out of six. The same research group later measured the same twenty archers again with a myotonometer, which reads the tone, stiffness and elasticity of a muscle at rest: in six muscles none of these properties changes significantly after a hundred arrows, and the stiffness of the posterior deltoid goes from 293.5 to 301.3 newtons per metre. Both papers also report a detail that changes how everything else reads, because those archers shoot 111 arrows per session on average: for them a hundred arrows are not an unusual load but an ordinary training session.
The same group has published three papers on these twenty archers, and the registry counts them as a single sample, since the people are the same. The claim that beyond 100 arrows in a session the shoulder muscles fatigue is contested: the same group of archers gives results pointing two ways, and the score was never counted. The same data also raised the question of whether men and women respond in the same way. The authors say they do, but their own tables find a difference in the middle trapezius precisely after the hundred arrows, with the peak going from 320 to 982 microvolts in the six women and from 406 to 464 in the fourteen men. With six women and a text that does not match the results, the claim that after a hundred arrows the shoulder muscles of men and women respond in the same way is contested as well.
From the shoulder to the bow
Two different studies have measured, in two steps, how muscle fatigue reaches the bow. In the first, the one with the seven university archers, the tremor that arises in the posterior deltoid between 8 and 12 hertz shows up in the oscillation of the bow limb, with a coherence between 0.81 and 0.96: a trembling muscle makes the bow tremble. In the second, twelve intermediate and high-level archers from the Italian federation did six sets of ten 20-second holds at full draw; afterwards the sideways sway of the bow while aiming had increased in all twelve, by 6 to 39% and 20% on average, while the centre of pressure under the feet had not shifted.
These are two small studies, neither with a control group, and fatigue was induced with holds rather than shots: that is why the claim that muscle fatigue increases bow sway while aiming is reported and not corroborated. There is also a detail that matters to anyone watching their own aiming. The same signal contains a slower oscillation, between 2 and 5 hertz, which the effort does not change and which, according to the authors, probably depends on movement control; on the target the two add up, and the eye cannot tell them apart. The rest of the story on movement while aiming is in the article on bow-arm tremor.
The score across a session
When it comes to the score, the picture changes. In the study of the twelve Italian archers, each one shot ten arrows at twelve metres before and after the sixty holds: the bow swayed 20% more on average, and nobody's score changed significantly. Ten arrows at twelve metres are a coarse measure, and an imposed isometric load is not a session, but the result points the same way as what was later seen in trained archers.
The only drop measured over a sequence of arrows comes from people who had never shot before: sixteen adults, eighty arrows each, and a score that fell by 8% on average from one block to the next, sooner and further with the more tiring grip. For many of them it was the first session of their lives, so tiredness is mixed up with learning. No such measurement exists for trained archers, so the claim that the score drops as the session goes on is transferred: it rests on people who were learning, not on people who train.
The measurements on competitive archers look at competition rather than training, and they tell a different story. In ten Brazilian archers with competition experience, over a simulated 60-arrow indoor round at 18 m, reported tiredness went from 2.3 before shooting to 3.8 at halfway and 5.8 at the end, on a scale of 0 to 10, while the two halves of the round were worth 218.8 and 216.0 points on average. In twelve Turkish university archers the score did not change from the first to the last end of a 30-arrow test, and in a single Malaysian archer, over seventy-two arrows at thirty metres, electromyography showed fatigue building while the second half finished on 318 points against 307, although within each set the lowest ends came towards the finish, by a few points and with no test to confirm it. At the only real competition read this way, a 2023 Arab championship, half of the 42 archers scored less in the second 70 m half, by 1 to 18 points, and half did not, in a reading of the results table with no test. The registry classes as reported the claim that in the second half of a competition the score does not drop, even though tiredness grows.
The gap between what archers feel and what they write on the scorecard has clear limits: short rounds, nearly all simulated, small samples, the only real competition read without a test, and a break at halfway in more than one study. Nobody has yet followed the score arrow by arrow through an actual training session of trained archers, which is exactly the situation the question comes from.
Skill level and fatigue
The idea that stronger archers cope better with fatigue is often heard, and three studies of archers point that way without being enough. Among the twelve Italian archers, bow sway rose less the higher the FITA score (r = -0.65), and the weaker archers raised biceps activity more; in the same study, though, the change in the centre of pressure did not depend on level, and two archers from the same group reacted very differently. In twenty young Swedish archers the better ones reported lower exertion, 9.5 against 12.9 on the Borg scale, but after twelve arrows. In a simulated 72-arrow round at 70 m a novice lost 10.8% of grip strength while an archer from the Brazilian national team stayed stable: that is two people. This is why the claim that higher-level archers cope better with the fatigue of shooting is reported, and nobody has yet shown that fatigue costs weaker archers more points.
The same comparison comes back when one asks how heavy a whole competition is. Eight archers from the Brazilian national team, after a simulated 144-arrow round, rated the day as tiring as a rest day, lost no grip strength and kept their lactate below 3 millimoles per litre. Each shooting block taken on its own, however, felt more tiring than the matching moment of the rest day, and cortisol rose after every distance, from the effort or from the tension of being assessed. The claim that shooting a full competition puts little physical strain on a trained archer is therefore contested, and in the data available the cost seems to depend more on the archer's level than on the format of the competition.
End of the session: still shooting, but how
Many archers describe the end of a long session in the same way: the arrows still go, but the shot is no longer the one they had at the start. The only data that asks exactly this question is a questionnaire given to university students who practise kyudo. Of 59 replies, 58% say that at the end of training they could still shoot but not with good form, 41% that they could do so with good form, and one person could no longer draw the bow. Alongside this impression there is the Malaysian archer, who named aiming as the hardest phase at the end of the session and towards the end of each set had to let down and repeat the shot several times. The registry classes as reported the claim that at the end of a training session archers can still shoot, but not with good form, with a clear limit: it is self-assessment, it comes from kyudo alone, and what gives way in the form, and after how many arrows, nobody has measured during an actual session.
Training to resist fatigue
That leaves the practical question of whether you can train to cope better. The closest study randomly split forty sub-elite Indonesian archers, aged 14 to 20, into four groups for twelve weeks: three shot at 20, 50 or 70 m under a fixed protocol of 108 arrows a session and no more than ten seconds per arrow, while the fourth kept to its usual training, also at 70 m. The fatigue index in a repeated-sprint test fell at 50 m, from 3.29 to 1.68, and at 70 m, from 4.84 to 2.95, but not significantly at 20 m or in the usual-training group, which also shot at 70 m, nor did the three protocol distances differ significantly. Distance alone is therefore not enough, and the claim that training at the longer distances improves resistance to fatigue is contested; a running sprint, after all, is not the ability to hold a score over the last ends. The strength work behind the hold has an article of its own, on specific strength for archers.
What I take from this to the shooting line
To the question I started from, from which arrow you are shooting tired, research today gives no number. A hundred arrows is a threshold that circulates, and the only group measured there shot them as an ordinary session, with results pointing two ways. What keeps recurring in the data is a gap: signs of fatigue appear in the shoulder and in the bow, tiredness is felt, while the score of trained archers, in simulated rounds, holds. I take three things from this, bearing in mind that none of them has been tested in an experiment on the score.
The first is to count. Writing down the number of arrows and the score of every end through the session, for a few weeks, gives an archer the measurement the studies do not yet have: their own curve, arrow after arrow. If the score does not drop, the tiredness felt at the end of the session is not yet costing points; if it always drops from the same point onwards, that is a personal figure more useful than any general threshold. For deciding the week's volume there is the article on how many arrows to shoot a week.
The second is to watch the shot before the target. The signs that turn up in the studies are aiming that takes longer, arrows let down and repeated, and a bow that sways more, and they are easy to pick up in a video filmed at the start and at the end of the same session, even when the scorecard has not moved yet. The third concerns the point of the last arrows. If the shot at the end of the session is no longer the one you want to train, as more than half of the kyudo practitioners questioned say, stopping or switching to other work is a reasonable training choice; it is not a research finding, because on this research has not yet measured anything.
What is missing
What is missing is a second sample, independent of the twenty Polish archers on whom the whole hundred-arrow question rests today, and archers of different levels followed through sessions of different length, with muscle activity, sway while aiming and score measured together. It would also help to compare levels under a load scaled to each archer's strength. Until those measurements arrive, fatigue in archery remains something that shows in the body and in the bow, and that has not yet shown up as a consistent drop in the score of trained archers.