Tai Chi before archery shooting: Li 2019 study

In 19 experienced archers in Hong Kong (13 women and 6 men, mean age 26 and 7.4 years of shooting), the authors compared 10 minutes of Tai Chi with 10 minutes of stretching as a warm-up before a shot under pressure: a single arrow at 18 metres, as in a shoot-off. The two conditions did not differ in heart rate variability (the ratio of low to high frequencies), in the attention and relaxation indices from an EEG headband, or in the arrow's distance from the centre.

With Tai Chi the mean distance from the centre fell from 5.58 to 4.49 cm, a significant change in the before and after comparison (p = 0.021); with stretching it went from 4.01 to 4.49 cm. The finding the authors stress most, though, is a different one: heart rate and EEG can be recorded during a simulated competition, and the archers said the equipment did not interfere with their shooting.

The study is a randomised crossover trial: each archer did both conditions, in an order decided by tossing a coin, at least a week apart, always in the evening at an indoor sports centre. Archers shot in pairs, matched by the coach on ability, with their own equipment. After two warm-up ends and sight adjustment they had 2 minutes of waiting on the shooting line and 15 seconds to shoot one arrow, whose distance from the centre was measured. Then came 10 minutes' rest, the exercise led by a video (seven Tai Chi forms repeated twice, or six arm and trunk stretches held for 15 seconds three times) and, within 5 minutes, a second arrow under the same conditions.

Heart rate was recorded with a Polar RS800CX monitor, brain activity with a NeuroSky MindWave headband, which outputs two indices from 0 to 100 labelled attention and meditation. None of the participants had done Tai Chi before.

Each shooting measure is a single arrow per condition and time point, and the distance of one arrow from the centre varies a great deal from shot to shot, as standard deviations of around 3 cm on means of 4 to 5 cm show. The improvement with Tai Chi has to be read knowing that in that condition the first arrow was further out (5.58 cm against 4.01) and that after the exercise both conditions ended at the same mean, 4.49 cm: this is the typical pattern of regression towards the mean rather than of an effect. The interaction between condition and time, the test that actually compares the two conditions, was not significant.

Bow type is not reported, the NeuroSky headband is a consumer device with unpublished algorithms, and the archers were learning Tai Chi on the spot, which the authors themselves think may have added tension rather than reduced it. It is a pilot study with 19 people, presented as groundwork for a larger trial.

For an archer, the upshot is that ten minutes of Tai Chi done for the first time did not measurably change heart rate variability, attention indices or the accuracy of the shoot-off arrow compared with ten minutes of stretching. The improvement with Tai Chi is easy to quote but, with a single arrow and a worse starting point, it does not hold up as evidence of a benefit.

The most useful part concerns method: heart rate and brain activity can be recorded on the shooting line, in a situation close to competition, without the archers feeling disturbed. For anyone who already uses Tai Chi or a slow warm-up before shooting, the study offers no evidence either way about the shoot-off.