2.2. Study Design
muscle damage, pain
CONTRACTIONS
This was a randomised, double-blind, placebo-controlled, cross-over intervention study. Eligible participants attended a familiarisation session at least one week prior to commencing the study. In this session, they were instructed on how to perform the bench-stepping exercise that they would be required to complete on their exercise trial day and the muscle function assessments on an isokinetic dynamometer (Biodex Medical Systems Inc., New York, NY, USA) that they would be required to undergo during their exercise trial and recovery days.All participants underwent a six-week dietary washout period where they omitted foods containing New Zealand GSM and supplements and foods high in omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Participants were randomised into either the PernaUltra GSM powder or placebo intervention group for the study’s first arm and asked to consume their allocated intervention daily for four weeks. Participants arrived on location within 24 h of their final supplementation day to complete their exercise trial day.Participants avoided strenuous exercise 48 h prior to their scheduled trial day. Upon arrival at the laboratory, participants completed the short-form McGill pain questionnaire (SF-MPQ) [Participants returned to the facility 24, 48 and 72 h post exercise for recovery assessments. On each visit, participants completed the SF-MPQ before donating a venous blood sample. After completing a five-minute warmup on a cycle ergometer, muscle function was assessed with the Biodex isokinetic dynamometer as well as perceived pain during the first eccentric and isometric contractions. During the 72 h recovery period, participants avoided strenuous exercise and continued to omit New Zealand GSM and foods and supplements that contained high concentrations of EPA and DHA from their diet.Before the beginning of the second trial arm, participants underwent another six-week dietary washout period. In the second trial arm, participants were supplemented with the dietary intervention that they were not allocated to during the first trial arm. Participants underwent the same muscle damage and recovery protocols but with the opposite leg to the one that had undergone eccentric muscle damage during the first trial arm. The participants’ progress through the phases of this randomised, cross-over study is illustrated in the Consolidated Standards of Reporting Trials (CONSORT) flow diagram (