Lynn 2015.

Methods	Randomised controlled trial (single‐blind, parallel design)
Participants	Setting: field; UK n = 21 (experimental group of 11, placebo group of 10; 2 participants were excluded from the bilberry group as they failed to report to the lab to provide follow‐up data), recreationally trained runners, age range 18 to 55 years Inclusion/exclusion criteria Individuals with cardiovascular disease, diabetes, hypertension, gastrointestinal problems, renal disease, musculoskeletal problems, regular antioxidant or NSAIDs use, and any food allergies were excluded from the study
Interventions	Intervention 2 x 200 mL of bilberry juice daily for 5 days before completing the Sheffield Half Marathon, on race day and for 2 days post‐race Total phenol content per 200 mL serving was 744.14 ± 81.75 mg (n = 3). and 80.04 ± 3.51 mg (n = 3) of total anthocyanins Placebo Energy matched control drink Duration 8 days
Outcomes	PRIMARY Delayed onset muscle soreness, 200 mm visual analogue scale, rated after a squat to a 90 angle and returning to a standing position: 0 "complete absence of pain" to 200 "indicating extreme soreness with noticeable pain and stiffness at all times"
Exercise type	Sheffield half marathon
Sources of funding	The study was funded by Sheffield Hallam University
Notes	2 x 200 mL of bilberry juice was consumed 5 days before the race, on the day of, and up to 48 hours post race
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	No details in published abstract Authors confirmed via email on 3 February 2017 that a "random numbers generator" was employed
Allocation concealment (selection bias)	Unclear risk	No details in published abstract Authors described via email on 3 February 2017 that the "Study was single blind so investigators knew which drink each participant got" and "drinks were given in non‐labelled container" Adequate safeguards not reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	No details in published abstract Authors described via email on 3 February 2017 that the "Study was single blind so investigators knew which drink each participant got" and "drinks were given in non‐labelled container" Not blinded
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Participants may have remained blinded but this is not confirmed
Incomplete outcome data (attrition bias) All outcomes	High risk	No details in published abstract Authors confirmed via email on 3 February 2017 that "Of the 21 participants, we missed getting data from 2, one missed the post race sample, and on the last day one other person was missed ‐ both were in the bilberry group"
Selective reporting (reporting bias)	Low risk	No published protocol All data available at all time points Personal communication: "None of the participants reported any adverse effects from consuming the Bilberry juice or the placebo"
Other bias	Low risk	Participants were asked to complete a food diary and were asked to refrain from using anti‐inflammatory drugs or other supplements that could reduce soreness