Kerksick 2009.

Methods	Randomised controlled trial (parallel design)
Participants	Setting: laboratory; USA n = 30 healthy non‐resistance trained men mean age 20 (SD 1.8) years Inclusion/exclusion criteria Non‐resistance trained men defined as less than 1 workout per month over the last 6 months. All participants were classified as low risk for cardiovascular disease with no contraindications to exercise according to the American College of Sports Medicine. No nutritional supplements (including multivitamins) were consumed at least 3 months prior to the study
Interventions	Interventions 1. 1800 mg N‐acetyl‐cysteine (NAC) 2. 1800 mg epigallocatechin gallate (EGCG) Placebo 1000 mg glucomannan Supplements were taken in the morning on an empty stomach and compliance was monitored by making phone calls and participants bringing back empty bottles during next visit Duration 14 days
Outcomes	PRIMARY Delayed onset muscle soreness was assessed at the quadriceps along a 10 cm visual analogue scale where 0 is "no soreness" and 10 is "extreme soreness" SECONDARY Peak isometric torque was assessed using a Biodex System‐3 isokinetic dynamometer 9 Biodex Medical Systems, Inc, NY, USA). Prior to testing participants warmed up on a cycle ergometer for 10 minutes. Changes in dynamic strength of the knee extensors was assessed by having participants complete 10 maximal repetitions in a concentric and eccentric fashion. Peak dynamic torque was measured in the dominant knee extensors, a total of 3 maximal voluntary contractions over 5 seconds duration were completed with 60 seconds rest in between each repetition. Participants were verbally encouraged to produce maximal effort throughout the entire 5‐second period. The peak torque exerted throughout all 3 repetitions was regarded as peak isometric torque. All isometric repetitions were completed at an angle of 90 degrees flexion.
Exercise type	10 sets of 10 repetitions at an isokinetic dynamometer; 1 minute rest between sets
Sources of funding	Partial funding for the study was provided by the National Strength and Conditioning Association through GNC Nutritional Research Grant, a Baylor University Faculty Research Award for Darryn Willoughby, PhD and HHPR a graduate student research award and indirect costs provided by grants awarded to Richard Kreider, PhD through the Exercise and Sports Nutrition Laboratory while at Baylor university
Notes	Authors were contacted on 2 November 2013 to request raw data for delayed onset muscle soreness and maximal voluntary isometric contraction and responded on 3 December 2013
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Participants were matched in clusters according to age and body weight for assignment
Allocation concealment (selection bias)	Low risk	Clear capsules provided
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	A total of 3 participants did not complete the study; 2 participants withdrew from the study and 1 was excluded due to non‐compliance Attrition rate: 10%
Selective reporting (reporting bias)	Low risk	No published protocol available All outcomes reported at all time points "No adverse outcomes were reported to the supplementation protocol"
Other bias	Low risk	Food records were obtained, participants were instructed to minimise foods high in quercetin and were asked to refrain from taking any other supplements or anti‐inflammatory medication or to engage in any other modality that could enhance recovery