Table 1.

Risk of bias in individual studies

Study	1. Was the group allocation randomized?	2. Do baseline characteristics suggest a successful randomization?	3. Were participants blinded to their group allocation?	4. Were investigators blinded to participants’ group allocation?	5. Were gold-standard methods used to measure outcomes?	6. Were the methods used to measure outcomes appropriate?	7. Was an appropriate statistical analysis used?	8. Were data for outcomes available for most participants?	9. Were missing data similar between groups?	10. Were data for all outcomes reported?	11. Was a statistical correction for multiple outcomes performed?	12. Was an appropriate sample size calculation performed?	13. Was the study registered beforehand?	Overall risk of bias
Alizadeh et al. [49]	Yes	Yes	No	No	No	Yes	Yes	No	No	Yes	Yes	Yes	No	High (6)
Blonc et al. [50]a	Yes	Yes	No	No	No	Yes	Yes	Yes	NA	Yes	No	No	No	High (7)
Boussetta et al. [51]	Yes	Yes	No	No	No	No	Yes	Yes	NA	Yes	No	No	No	High (8)
Brito et al. [52, 53]	Yes	Yes	No	No	Yes	Yes	Yes	Yes	NA	Yes	Yes	No	Yes	Moderate (4)
Brooker et al. [54]	Yes	Yes	No	No	Yes	Yes	NA	Yes	NA	Yes	NA	No	Yes	High (6)
Brooker et al. [55]	Yes	Yes	No	No	Yes	Yes	Yes	Yes	NA	Yes	No	No	Yes	Moderate (4)
Chiang et al. [56]	Yes	Yes	No	No	No	No	Yes	Yes	NA	Yes	Yes	No	Yes	High (6)
Chtourou et al. [57]ª	Yes	Yes	No	No	No	No	Yes	Yes	NA	Yes	No	No	No	High (8)
Chtourou et al. [58]ª	Yes	Yes	No	No	No	Yes	Yes	Yes	NA	Yes	No	No	No	High (7)
Chtourou et al. [59]ª	Yes	Yes	No	No	No	Yes	Yes	Yes	NA	Yes	No	No	No	High (7)
Ferchichi et al. [60]	Yes	Yes	No	No	No	Yes	Yes	Yes	NA	Yes	No	No	No	High (7)
Gueldich et al. [61]	Yes	Yes	No	No	No	Yes	Yes	Yes	NA	Yes	No	No	No	High (7)
Krčmárová et al. [62]	Yes	Yes	No	No	No	No	Yes	Yes	NA	Yes	No	No	No	High (8)
Saidi et al. [63]	Yes	Yes	No	No	No	No	No	Yes	NA	Yes	No	No	No	High (8)
Savikj et al. [64]	Yes	Yes	No	No	No	No	Yes	Yes	NA	Yes	Yes	No	No	High (7)
Sedliak et al. [65–67]ª	Yes	Yes	No	No	No	Yes	Yes	No	Yes	Yes	No	No	No	High (7)
Sedliak et al. [68]	Yes	Yes	No	No	Yes	Yes	Yes	No	No	Yes	No	No	No	High (7)
Silva et al. [69]	Yes	Yes	No	No	No	No	Yes	Yes	NA	Yes	Yes	No	No	High (7)
Souissi et al. [70]ª	Yes	Yes	No	No	Yes	Yes	Yes	Yes	NA	Yes	No	No	No	High (6)
Souissi et al. [71]	Yes	Yes	No	No	No	Yes	Yes	Yes	NA	Yes	No	No	No	High (7)
Teo et al. [72, 73]	Yes	Yes	No	No	No	Yes	Yes	Yes	NA	Yes	Yes	Yes	Yes	Moderate (4)
Zbidi et al. [74]ª	Yes	Yes	No	No	No	Yes	Yes	Yes	NA	Yes	No	No	No	High (7)

Description indicating when a criterion has been answered with "yes": 5. gold-standard declarations: body composition = dual-energy x-ray absorptiometry, magnetic resonance tomography; jump height = force plate, infrared system; strength = isokinetic dynamometer, isometric dynamometer; glucose control = glucose clamp technique, intravenous glucose tolerance test. 6. appropriate methods in addition to the gold standard: body composition = bioelectrical impedance analysis, skinfold thickness; jump height = jump meter; strength = strain gauge, acceleration sensor; glucose control = oral glucose tolerance test, HbA1c (if exercise intervention is longer than 2 months). 8. cutoff: drop-out rate > 20%. 11. performing a statistical correction for multiple outcomes: definition of a primary outcome, valid sample size calculation for one outcome, trial registration with primary outcome. 12. performing an appropriate sample size calculation: precise sample size calculation with preliminary evidence for effect size. Overall risk of bias assessment: number of questions not answered with yes, 0–2 = low risk of bias, 3–5 moderate risk of bias, 6–8 high risk of bias, 9–11 very high risk of bias, 12–13 not included in this review due to inclusion criteria

ªIntervention studies included in the meta-analysis