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Table 1 Risk of bias in individual studies

From: Best Time of Day for Strength and Endurance Training to Improve Health and Performance? A Systematic Review with Meta-analysis

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

Yes

Yes

No

No

No

No

Yes

Yes

NA

Yes

No

No

No

High (8)

Chtourou et al. [58

Yes

Yes

No

No

No

Yes

Yes

Yes

NA

Yes

No

No

No

High (7)

Chtourou et al. [59

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. [65,66,67

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

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

Yes

Yes

No

No

No

Yes

Yes

Yes

NA

Yes

No

No

No

High (7)

  1. 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
  2. ªIntervention studies included in the meta-analysis