The effects of sex and flexibility on indirect markers of muscle damage following a bout of eccentric exercise

Hodgson, Sarah Ann (2014) The effects of sex and flexibility on indirect markers of muscle damage following a bout of eccentric exercise. Masters by Research thesis (MSc), Manchester Metropolitan University.

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Abstract

Aim: This study examined the effects of sex and flexibility on differences in serum Creatine Kinase (CK), muscle strength and muscle soreness following a bout of maximal eccentric exercise. Method: 10 males and 10 females were recruited for this study, none of which had performed regular resistance or flexibility training within the last year. All participants performed three baseline flexibility measures (sit and reach, standing range of motion and supine range of motion) of the knee flexors to determine levels of flexibility. Participants then performed sixty maximal eccentric contractions of their non-dominant knee flexors. Markers of muscle damage were documented by changes in maximal voluntary contraction (MVC), CK levels and muscle soreness of the knee flexor muscle group. Muscle damage markers were recorded pre (before), post (1 hour after), two, four and seven days following the eccentric exercise. Results: Analysis revealed a significant main effect of time on markers of muscle damage (relative knee flexor MVC torque, CK levels and muscle soreness) in both males and females following a bout of eccentric exercise. No significant main effect of sex was observed on markers of muscle damage (relative knee flexor MVC torque, CK levels and muscle soreness) following a bout of eccentric exercise. No significant association was observed between knee flexor flexibility and indirect markers of muscle damage at any time point following eccentric exercise, even when the cohort was pooled. Conclusion: In response to eccentric exercise there is no effect of sex or knee flexor flexibility on markers of muscle damage. The findings indicate that natural differences in flexibility, such as that seen between the sexes, has no attenuation effect on functional parameters following eccentric exercise. Further research should focus on the differences in stress/strain between the sexes and its effect on markers of muscle damage.