Close 2006.
| Methods | Randomised controlled trial (parallel design) | |
| Participants | Setting: laboratory; UK n = 20 physically active males naive to downhill running Placebo group mean age 22.1 (SEM 0.4) years (n = 10) Vitamin C group mean age 24.2 (SEM 1.5) years (n = 10) Inclusion/exclusion criteria All participants were non‐smokers and free from any known illness as ascertained by questionnaire Participants taking any form of vitamin supplementation were excluded |
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| Interventions |
Intervention 1 g of vitamin C supplementation Placebo Lactose placebo Duration 14 days |
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| Outcomes |
PRIMARY Delayed onset muscle soreness was measured at the gastrocnemius, anterior tibialis, hamstrings, quadriceps, gluteals (both sides) and lower back muscles using a 10‐point visual analogue scale where 0 is "no pain" and 10 is "extreme pain" SECONDARY Muscle function was performed an isokinetic dynamometer. The test involved concentric quadriceps muscle torque assessment at 1.06 and 5.20 rad/second as well as eccentric quadriceps assessment at 2.6 rad/second Muscle tenderness was measurement using pressure algometry at the gastrocnemius, anterior tibialis, hamstrings, quadriceps, gluteals (both sides) and lower back muscles |
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| Exercise type | 30 minutes of downhill running on a treadmill at a grade of ‐15% at 60% VO2max | |
| Sources of funding | None | |
| Notes | No details on whether supplement was administered as a drink or a capsule or a powder Authors were contacted to request raw data for PPT, delayed onset muscle soreness and maximal voluntary isometric contraction on 3 October 2013 and responded on 3 December 2013 |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | No details in manuscript Authors were contacted via email 17 May 2016 Author response: "A random number generator to allocate into groups and from memory they were block randomised according to their VO2max" |
| Allocation concealment (selection bias) | Low risk | No details in manuscript Authors were contacted via email 17 May 2016 Author response: "All supplements were given in visually identical capsules double blind" |
| 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 | All participants completed the study with no adverse effects |
| 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 | Low risk | Participants were asked to refrain from using anti‐inflammatory medication and other supplements for the duration of the study as well as any form of therapeutic intervention such as massage and ice |