Diaphragmatic breathing outside archery: Ma 2017

The study is not about archery: it is an eight-week trial of diaphragmatic breathing in employees of an IT company in Beijing, healthy adults with no experience of yoga, tai chi, qigong or other mind-body practices. Of the 40 participants, 20 had 20 sessions led by an instructor, with a sensor that recorded their breathing, and the other 20 only took the tests.

In the trained group the rate of slow breathing fell from 9.95 breaths per minute in the first session to 3.45 in the twentieth, while resting breathing stayed between 14.82 and 19.73. At the end of the eight weeks the trained group's negative affect score on the PANAS was 2.55 points lower, with no change in positive affect; in the control group negative affect did not move. On the sustained attention test, which involves crossing out target digits on sheets of 200 digits, both groups improved: the trained group by 6.728 points and the controls by 4.19. Salivary cortisol, collected between 11:00 and 12:00, was lower at the end in the trained group and did not change in the controls.

Participants were allocated by alternating the order in which they registered, with 10 women and 10 men per group. Each session, held on alternate weekdays, lasted 30 minutes: 15 of normal breathing with eyes closed and 15 of diaphragmatic breathing, inhaling deeply as the abdomen expands and exhaling as slowly as possible, with spoken guidance from the instructor and a sensor on the chest or abdomen that recorded the breathing curve, which the assistants followed on screen (participants kept their eyes closed). If the rate stayed above 6 breaths per minute after 2 minutes, the instructor stepped in. The control group received only an introduction to breathing, and their breathing was recorded on the first and last days.

Before and after the programme everyone completed the PANAS, a 20-item scale on mood over the past week, and the Number Cancellation Test, four one-minute sheets on which participants cross out the 9s that carry certain symbols. Salivary cortisol was measured before and after a session of diaphragmatic breathing at the start and end of the study. Sessions and tests took place in a meeting room at the company, so that participants did not have to travel to a laboratory.

The paper presents itself as a randomised trial, but allocation was by alternating registration order, which is not randomisation. The control group did nothing: there is no comparison activity with the same time, the same attention from an instructor and the same break from work, so the effect of the breathing cannot be separated from that of half an hour of guided calm two or three times a week. Participants were told the purpose only at the end, but those in training knew they were training.

Several figures do not add up. For negative affect the group-by-time interaction is only close to significance (p = 0.07), and the rest rests on within-group comparisons. For attention both groups improved, the trained group slightly more, the text calls a group effect with F = 0.01 and p = 0.93 significant, and a figure caption announces a difference between the groups that it then says was not found. The analysis of breathing rate has degrees of freedom consistent with eight people, and the tables list 19 participants in the trained group rather than 20, without explanation. Means and standard deviations for the psychological tests appear only in the figures, and the sample consists of healthy office workers, not athletes.

For an archer this study matters only indirectly, as evidence about a technique many people use before shooting. It shows that healthy adults trained for eight weeks with an instructor and their breathing recorded learn to breathe at 3 to 4 breaths per minute, and at the end report slightly less negative mood and have lower late-morning salivary cortisol than people who did nothing. The attention result is weak: the trained group improved slightly more, but the group that did not train improved too.

It says nothing about competition, performance anxiety, heart rate while shooting or score, and breathing this slow is not what archers do on the shooting line between arrows. It should be read as a study of office workers' wellbeing, not as evidence for breathing techniques in archery.