Grip strength training and archery accuracy: Sezer 2017

Thirty male archers aged 18 to 20 from the youth team in Elazığ, Turkey, were split into two groups of 15. One group followed a 12-week strength programme, one hour three times a week; the other did not. At the end the trained group squeezed harder on the dynamometer: from 63.21 to 75.12 kg with the right hand and from 58.21 to 69.12 kg with the left, while the control group stayed where it was (64.70 to 64.23 and 60.55 to 60.23 kg). Sit-ups, pull-ups and push-ups in 30 seconds also went up, and the heart rate counted straight after exercise fell by about 4 beats a minute.

In the shooting test, 12 arrows at 18 metres on a 40 cm face, the trained group went from an average of 68.10 to 89.71 points, a gain of 21.61 points out of a possible 120; the controls went from 64.42 to 67.66, a difference that was not significant (p=0.481). Before the programme no strength measure was related to score. Afterwards, and only in the trained group, grip strength was (r=0.729 right, 0.731 left), along with height, which had a negative sign (r=-0.762). From this the author concludes that grip strength, and training it, improves shooting accuracy.

The participants were volunteers from the team; the paper does not say how they were allocated to the two groups, nor whether the controls carried on shooting as before. The programme was not limited to grip work: besides a spring hand gripper and a forearm twister it included shoulder presses, leg extensions, chest presses, dips, lat pull-downs, biceps curls, triceps extensions and abdominal work, all in 3 sets of 6 repetitions, with intensity set at 80% of heart rate reserve (the Karvonen formula). Sessions lasted 40 minutes at the start and grew by 10 minutes in the fifth and ninth weeks.

Grip strength was measured with a Jamar hydraulic dynamometer, standing with the arm straight, keeping the best of three attempts for each hand. Heart rate was counted with a stethoscope over 15 seconds. The shooting test followed the indoor rules: 4 ends of 3 arrows, with 124 seconds per end; the type of bow is not stated. The analysis compares before and after within each group, with the test described in different places as a t test, ANOVA or Kruskal-Wallis, and then relates strength to score with simple regressions on 15 people.

The finding on score is weak. Twelve arrows are a very small sample for judging an archer's level, and an average jump from 68 to 90 points in three months, from about 5.7 to 7.5 per arrow, is far more than a general strength programme could reasonably be expected to deliver; we do not know how much either group shot in the meantime, and the two groups are never compared directly after the programme. The groups already differed in height at the start (1.67 against 1.75 m) and the allocation is not described. Correlations on 15 people are unstable: the one with height moves from -0.458 to -0.762 although nobody's height changed.

The text also has internal inconsistencies. The abstract gives the shooting scores as 58.21 and 69.12, which in the table are the left-hand grip values; the table gives the scores as 68.10 and 89.71. The p value for the controls' resting heart rate is 0.070 in the table and 0.970 in the text. Grip values above 60 kg in 19-year-olds are much higher than the figures the paper itself quotes for boxers, wrestlers and fencers. The journal is flagged in the registry for questionable editorial standards.

For anyone who shoots, the study does not allow us to say that training grip raises scores. The programme was whole-body strength work, and the gain of more than 21 points over 12 arrows cannot be separated from everything else those young archers did in three months. The solid part is the predictable one: three strength sessions a week for 12 weeks raise grip strength and bodyweight test results in young archers.

There is also a point about technique. The study starts from the idea that an archer has to grip the bow and arrow hard; in modern recurve shooting the bow hand pushes into the grip without squeezing it, and the fingers hold the string only as firmly as they need to until the release, so it is not obvious that a higher maximum grip matters to the shot. The study measures none of this, neither how the string is held nor stability while aiming. In the registry it stands as an example of a striking result from a weak design, to be read with caution.