Cobley 2011.

Methods	Randomised controlled trial (parallel design)
Participants	Setting: Laboratory and Field; UK n = 14 recreationally trained males mean age 24.7 (SD 4.2) years (6 in each group) 2 participants dropped out for personal reasons Inclusion/exclusion criteria Recreationally trained was defined as participating in physical activity of an intermittent nature at least 3 times per week for at least 12 months. Prospective participants were excluded if they smoked or engaged in any course of supplementation or medication (e.g. antioxidant supplementation) that may have interfered with the study's results.
Interventions	Intervention N‐acetylcysteine supplementation 50 mg/kg Placebo Water and cordial Duration 6 days
Outcomes	PRIMARY Delayed onset muscle soreness was assessed by a 12‐point visual analogue scale where 0 is "no pain" and 12 is "intolerable pain". Participants were required to mark a point on the VAS that corresponded to their perception of total muscle soreness after performing a 90 degree squat. SECONDARY Absolute muscle torque was determined in the dominant limb concentric quadriceps using a Isokinetic Dynamomter (Biodex Medical Systems, Shirely, NY). Concentric quadriceps torque was determined at 60, 180 and 300 rad/second. 3 maximal repetitions were performed at each speed with the greatest value attained being recorded. Yo‐Yo Intermittent Recovery Test Level 1. Involves the performance of consecutive 2 x 20 m shuttles separated by 10 seconds recovery intervals. Running velocity is dictated by audio beeps and increased by 0.5 km/hour throughout the test until volitional exhaustion ensues. Loughborough intermittent Shuttle Test was completed in a well‐ventilated indoor runway. This consists of successive cycles of cruising at 95% VO2max (60 m), jogging at 55% VO2max (60 m), walking (60 m) and maximally sprinting (20 m) between 2 pairs of timing lights placed 20 m apart in time with audio beeps for 15 minutes Side effects on a scale of 0 to 10
Exercise type	Loughborough intermittent Shuttle Test and Yo‐Yo Intermittent Recovery Test Level 1
Sources of funding	None
Notes	N‐acetylcysteine and placebo supplementation mixed in water Authors were contacted to request raw data for delayed onset muscle soreness, maximal voluntary isometric contraction and performance data on 3 December 2013 and responded on 5 December 2013
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Pair‐matched based on performance on the baseline test
Allocation concealment (selection bias)	Low risk	Not specified in manuscript Authors were contacted on 21 February 2017 and replied "treatment allocation was done in sealed opaque containers"
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	2 participants dropped out for personal reasons Attrition rate: 14.3%
Selective reporting (reporting bias)	Low risk	No published protocol available All outcomes reported at all time points
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