Sellwood 2007a.

Methods	Randomised controlled trial
Participants	N = 40 healthy adults, mean age 21.3 (SD 4.3), 11 male / 29 female
Interventions	Cold‐water immersion (n = 20): Immersion in water at 5°C, 1 minute x 3 sets. Warm‐water immersion (n = 20): Immersion in water at 24°C, 1 minute x 3 sets Both groups: Immersion to anterior superior iliac spine, participants rested out of the bath for 60 seconds between sets
Outcomes	Pain Pain during: sit‐stand, passive stretch, hopping, running, isometric contraction (100 mm visual analogue scale, "no pain" to "worst pain possible") Tenderness Pain (100 mm visual analogue scale) when pressure applied at two points on the thigh, pressure standardised at 6 lb/cm2 using an algometer) Strength Isometric knee extension (isokinetic dynamometer, 60° flexion, Nm) Power Hop for distance (tape measure, m) Swelling Thigh circumference (use of tape measure?, mm) Biomarker Muscle damage (CK, IU/L) (Follow‐up: 24, 48 and 72 hours after exercise)
Exercise type / intensity	5 sets of 10 repetitions of eccentric quadriceps exercise at 120% of 1 repetition maximum, leg extension machine, 1 minute rest between sets
Time between completing exercise and initiating intervention	Immediate
Participants' fitness level	No eccentric quadriceps exercise within past 3 months
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Generated using a random numbers table" (Methods, randomisation and masking, pg. 393)
Allocation concealment (selection bias)	Low risk	"Sequentially numbered opaque sealed envelopes held at a central location" (Methods, randomisation and masking, pg. 393)
Blinding (performance bias and detection bias) Participants	High risk	Difficult due to nature of intervention, however participants were not informed as to which intervention was considered therapeutic (Methods, randomisation and masking, pg. 393)
Blinding (performance bias and detection bias) Personnel	High risk	No details
Blinding (performance bias and detection bias) Outcome assessors	Low risk	"Investigator responsible for outcome assessments was blinded to group allocation, and participants advised not to reveal their allocation" (Methods, randomisation and masking, pg. 393)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data analysis (pg. 395) states that analysis was based on ITT, with imputation using Last Observation Carried Forward (LOCF) in the event of missing data drop outs/missing data is not reported in text however Table 5 which states that n = 20 were followed up in each group; therefore likely that imputation (LOCF) was not required
Selective reporting (reporting bias)	Low risk	No published protocol available Outcomes and follow‐ups stated in methods Means and SD (or median and IQ range) presented by intervention group for all outcomes, at all follow‐ups
Other bias	Unclear risk	Exercise protocol clearly described No details on co‐interventions