Table 4.

Certainty of evidence for each outcome

Outcome	No. of studies	No. of participants	Estimated effect (as SMD)	Certainty of evidence (GRADE)
Fat-free mass	8	418	0.48	⨁⨁⨁◯ moderated
Tendon morphology	4	114	0.67	⨁◯◯◯ very lowb,c,d
Tendon mechanical properties	4	111	0.05	⨁◯◯◯ very lowa,c,d,e
Muscle architecture	5	161	0.39	⨁⨁◯◯ lowc,d
Maximal strength	11	511	0.19	⨁⨁◯◯ lowc,d
Recovery maximal strength post	3	98	0.15	⨁⨁◯◯ lowc,d
Recovery maximal strength 24 h	4	113	0.26	⨁⨁◯◯ lowc,d
Recovery maximal strength 48 h	4	113	0.31	⨁⨁◯◯ lowc,d
Recovery reactive strength 24 h	3	91	0.41	⨁⨁◯◯ lowc,d
Recovery reactive strength 48 h	3	91	0.43	⨁⨁◯◯ lowc,d
Recovery muscle soreness post	4	121	− 0.21	⨁⨁◯◯ lowc,d
Recovery muscle soreness 24 h	4	127	− 0.05	⨁⨁◯◯ lowc,d
Recovery muscle soreness 48 h	5	135	0.09	⨁⨁◯◯ lowc,d

Reasons for downgrades: a = risk of bias, b = inconsistency/heterogeneity, c = participants and/or interventions differed (training history, duration, study design), d = imprecision/ wide confidence intervals, e = publication bias (detected via Egger’s test)

SMD standardized mean difference