Concentration and archery accuracy: Nurida 2026 study

Forty-five junior archers of the Indonesian national division, all the Perpani members of the Boyolali district, measured once in April 2026 on three things: concentration, arm endurance and score.

Concentration with the grid test: one hundred cells with two-digit numbers from 00 to 99, to be joined from smallest to largest in sixty seconds, the score being how many are found in order. Arm endurance with push-ups: how many are done in sixty seconds without pausing, with the women performing them resting on their knees. The score with thirty-six arrows at thirty metres.

The numbers. Concentration between 14 and 29, mean 21.82 ± 4.16. Push-ups between 19 and 38, mean 27.89 ± 4.94. Mean score 315.11 ± 13.89 out of 360, that is 8.75 points per arrow.

The three measures relate to one another. Concentration with the score gives r equal to 0.702 at p below 0.001; push-ups with the score r equal to 0.633, also below 0.001. Put together in a multiple correlation they give R equal to 0.762 and R squared 0.581, with F equal to 29.086: the two measures account for 58.1 per cent of the differences in score among these forty-five archers. The two predictors partly overlap with each other, with a tolerance of 0.698 and a variance inflation factor of 1.432, which corresponds to a correlation of about 0.55 between concentration and push-ups.

The article's arithmetic is internally consistent, and this deserves saying because it is not the rule in this literature. Starting from the two simple correlations and the overlap between the predictors, R squared comes back at 0.5805 against the 0.581 stated, R at 0.762 against 0.762, and F at 29.06 against 29.09. The preliminary checks are reported and they hold: normality of the three variables, linearity of both relationships and no excessive collinearity.

A survey with a correlational approach and data collected on a single occasion, from 3 to 5 April 2026, on the field of the Kebogiro stadium in the Boyolali district. The sample coincides with the population: forty-five junior archers of the national division, all of them taken, by total sampling. Nothing is reported about the participants beyond this: no age, no composition by sex, no years of practice, no draw weight.

The grid test for concentration comes from a secondary source, and the article credits it to Harris and Harris and to Marten giving the years 1894 and 1933, which are a century away from that instrument's date. The reliability reported, r equal to 0.79 on a retest, is taken from the same source and not measured here. The grid has one hundred cells with two-digit numbers from 00 to 99; they are crossed off in ascending order for sixty seconds, seated, and those found in sequence are counted. The test was done once. The article also gives the judgement bands: twenty-one and above excellent, sixteen to twenty good, eleven to fifteen adequate, six to ten poor, five and below very poor.

The push-ups follow a protocol cited from another source: sixty seconds, hands shoulder-width apart, arms extended, descent to ninety degrees, return to extended arms, without pausing, counting the repetitions. For the women the protocol is modified with the knees resting and a start from the mat.

The score comes from an instrument cited with a validity of 0.922 and a reliability of 0.738: thirty-six arrows at thirty metres, with each archer's own bow, a target, a backstop and a scoring sheet.

The analysis is in SPSS 25: Shapiro and Wilk test for normality, which passes on all three variables with significance values of 0.749, 0.091 and 0.156; a linearity test on the deviation from linearity, which passes with 0.915 and 0.114; a collinearity test with tolerance and variance inflation factor; then a simple Pearson correlation for each predictor and a multiple correlation for the two together.

Here the problem is not in the arithmetic, which holds, but in what was measured.

Arm endurance is measured with push-ups, that is with a push, while drawing a bow is a pull. The same article's introduction lists the muscles needed to draw and hold, namely fingers, trapezius, biceps, rhomboid, deltoid and triceps, and then the measure chosen is the number of push-ups in a minute, where the work is done by the pectoral, the anterior deltoid and the triceps in pressing. Between what the article describes as necessary and what it measures there is a difference of movement, and the study does not reveal whether the association concerns the endurance useful for shooting or general physical condition.

The same measure, moreover, is not the same for everyone. The women perform the push-ups with their knees resting, the men with arms and legs extended: these are two different tests whose results end up in a single variable. How many women and how many men there were is not reported, and sex does not enter the analysis. If the boys did more push-ups and also shot higher scores, which is plausible in a junior category where draw weight depends on build, part of that 0.633 would be the difference between the sexes rather than a link between endurance and accuracy.

Nothing else is known about the participants. No age, no years of practice, no draw weight: in a group of juniors from a single district, those training longer tend to have better scores, more push-up repetitions and more familiarity with a grid test to be done in a minute. Both predictors may therefore be partly measures of the same thing, how far along someone is, and the correlation of about 0.55 between them is consistent with that reading. The study has no variable with which to allow for it.

The design is cross-sectional, one measurement each across three days, and the language of the conclusions is not. The abstract says the two measures contributed 58.1 per cent to accuracy, the discussion says that more endurance brings more accuracy, and the conclusions ask coaches to build physical and mental programmes. From a correlation measured once it does not follow that training concentration or push-ups raises the score: what follows is that in this group the three things go together.

On the measurement of concentration, a grid test done once for sixty seconds is a noisy snapshot: the reliability cited, 0.79, comes from another study, and here no repetition allows it to be estimated. Someone more used to paper tests, besides, finds more numbers at the same ability to concentrate on shooting.

The sample coincides with the population of a single district, so the study describes Boyolali rather than Indonesian juniors, and the score is at thirty metres on the large face, that is in the easiest format: a mean of 8.75 points per arrow does not compare with scores at seventy metres.

Incidental imprecisions remain that a reader notices: the grid test credited to 1894 and 1933, a bibliographic reference in which the author reads Sports Science et al., another carrying the title inside the author's name, and in the collinearity table the heading VIVID instead of VIF. In the text extracted from the PDFs the minimum and maximum of the score do not appear, while the registry has them as 281 and 345: an earlier session read them, so the table contains them and the extraction lost them.

What remains from this study is an order of magnitude for how much of the variation in score, within a group of juniors, goes together with two things measurable in half an hour: a paper concentration test and the number of push-ups in a minute. Together they sit with 58 per cent of the differences, and separately with r of 0.70 and 0.63. These are high numbers for this literature, and the article's arithmetic is consistent, which in this batch is not the rule.

What cannot be drawn from it is that training those two things raises the score. The measurement is a single snapshot: it says that in that group those scoring more points also tend to find more numbers in the grid and do more push-ups, not that doing more push-ups scores more. The article, instead, writes that the two measures contributed to accuracy and asks coaches for programmes, which is a step beyond what the design allows.

There is then something an archer notices at once: push-ups are a push, and drawing a bow is a pull. The article itself, in its introduction, lists fingers, trapezius, biceps and rhomboid among the muscles needed, and then measures a movement in which those do not work. Anyone wanting to use this result to choose an exercise would be looking in the least suitable place. It remains plausible that push-ups here work as an indicator of general physical condition, and that it is that which goes together with the score.

Finally the detail that weighs most on the reading: the women did the push-ups on their knees and the men with legs extended, the two results sit in the same variable, and how many of each there were is not written. In a junior category, where build also decides draw weight, that correlation may contain the difference between boys and girls.

The registry keeps this work as the largest cross-sectional measurement on the side supporting a link between arms and accuracy, with the reservation that endurance is measured with a pushing movement and with two different protocols according to sex, and for the mean score per arrow at thirty metres.