Meamarbashi 2011.

Methods	Randomised controlled trial (parallel design)
Participants	Setting: laboratory, Iran n = 20 male non‐athletic university students mean age 18.2 (SD 0.4) years Inclusion/exclusion criteria Participants were selected based on fitness and health screening tests and recruited in a double‐blind trial. Participants with history of any type of muscle injury, chronic inflammation, coagulation disorders, immune system impairment and cardiovascular problems were excluded. Participants were also excluded if they regularly participated in vigorous exercise in the previous 3 months.
Interventions	Intervention Purslane extract 1200 mg given as 2 x 600 mg capsules per day Placebo Lactose powder placebo capsules Duration 5 days
Outcomes	PRIMARY A general rating of muscle soreness was assessed using a 0‐ to 6‐point scale where 0 corresponded to "no pain" and 6 to "unbearably painful". Participants were requested to rate the discomfort in only the quadriceps and calf regions of the right leg. SECONDARY Knee range of motion ‐ participants laid prone on an examination table with both knees fully extended. The knee joint angle was determined by using a goniometer and universal landmarks to ensure alignment. Knee flexion range was determined when the participant maximally and voluntary flexed the knee. Maximal knee extension isometric force was evaluated using a computerised dynamometer attached to an adjustable steel chain. Participant was seated on a special chair with knee flexed at an angle of 90 degrees then the ankle was fixed by a special belt connected to a force transducer. During a 5‐second test, force‐time data were recorded on a memory card.
Exercise type	7 sets of 5 minutes of continuous bench stepping exercise with 1 minute rest; 50 cm bench height
Sources of funding	Financial support was received from the university postgraduate grant (no 11‐4‐899). University of Mohaghegh Ardabil, Iran
Notes	2 capsules daily
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	No details in the manuscript Authors were contacted by email on 25 May 2016 Response: "two groups had selection criteria's and randomly selected by online program from a bigger group of volunteers"
Allocation concealment (selection bias)	Low risk	No details in the manuscript Authors were contacted by email on 25 May 2016 Response: "placebo and purslane were capsulated"
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
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 any supplements and anti‐inflammatory drugs or other treatment that could reduce soreness. Diet not controlled.