Table 3

Meta-analysis for each outcome measure

Outcome	Comparisons (n)	Meta-analysis of each outcome			Test of heterogeneity
Outcome	Comparisons (n)	SDM	CI	P value	I² (%)	P value
Aerobic performance	60	0.051	−0.020 to 0.122	0.156	0	0.893
Physical performance	53	0.047	−0.028 to 0.121	0.218	0	0.778
VO_2max	28	−0.013	−0118 to 0.092	0.809	0	0.999
Time trial	17	0.059	−0.064 to 0.182	0.345	0	0.999
To exhaustion	36	0.043	−0.059 to 0.144	0.411	26	0.260

Aerobic performance: maximal physical performance lasting more than 1 min.
Physical performance: time to exhaustion, distance covered in a preset time, time to cover a distance/amount of work or contractions to task failure. If a study reported both VO_2max/peak and physical performance, physical performance was included in aerobic performance. If only VO_2max/peak was reported, VO_2max/peak was included in aerobic performance.
Time trial: closed-ended tests.
To exhaustion: open-ended tests.
I²: the proportion of variance that is due to real differences in effect size.
SDM, standardised difference in mean; VO_2max/peak, maximal oxygen consumption.