Nie 2004.
| Methods | Randomised controlled trial (parallel design) | |
| Participants | Setting: laboratory; China n = 16 male junior basketball players (8 in each group) Mean age vitamin C group 16.7 (SD 0.3) years Mean age placebo group 16.5 (SD 0.2) years Inclusion/exclusion criteria Participants completed 4 to 5 training sessions a week with an average weekly training of 12.3 (SD 1.3) hours |
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| Interventions |
Intervention 800 mg of vitamin C Placebo No details provided other than it was identical in appearance Duration Vitamin C taken 3 hours before exercise and 31 hours after exercise and outcomes measured for up to 2 days post‐exercise |
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| Outcomes |
PRIMARY Delayed onset muscle soreness was evaluated in the leg extensors using a 10 cm visual analogue scale where 0 is "complete absence of pain" and 10 is "extremely sore with noticeable pain and stiffness at all times and the muscle and leg are difficult to use". Perceived soreness was done during quadriceps extension. |
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| Exercise type | 10 sets of 15 full‐squat jumps with 10 kg weight imposed at the waist | |
| Sources of funding | None | |
| Notes | No detail on how the supplements were administered or whether it was a drink or capsule | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | No details in manuscript Authors were contacted via email on 26 May 2016 and responded on 27 May 2016: "distribute subjects by lot" |
| Allocation concealment (selection bias) | Unclear risk | No details in manuscript Authors were contacted via email on 26 May 2016 and responded on 27 May 2016 but did not understand the query |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Double‐blind |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Double‐blind |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | No details in manuscript Authors were contacted via email on 26 May 2016 and responded to say that all participants completed the study |
| Selective reporting (reporting bias) | High risk | No published protocol available All outcomes reported at all time points Adverse effects of antioxidant supplementation were not reported |
| Other bias | Unclear risk | Diet was controlled 2 days before testing, however no details were provided on whether participants were instructed to avoid other supplements or anti‐inflammatory drugs during the study |