The influence of set-repetition configuration in eccentric exercise on muscle damage and repeated bout effect

It is well known that maximal eccentric exercise induces muscle damage, especially when it is performed for the first time. However, muscle damage is attenuated in subsequent bouts of the same or similar exercise, which is known as the repeated bout effect. One of the factors affecting the magnitude of muscle damage and the repeated bout effect is the number of eccentric contractions; however, it is unknown if different set-repetition configurations with the same number of eccentric contractions would result in different magnitudes of muscle damage and adaptation. This study investigated changes in muscle strength, range of motion (ROM), muscle cross sectional area (CSA), muscle soreness and plasma creatine kinase (CK) activity following an initial bout of maximal eccentric contractions with the same total number of contractions but different set-repetition configurations (e.g. 3 sets of 10 reps vs. 10 sets of 3 reps) and a second bout (20 sets of 3 repetitions) separated by four weeks. Since the present study was the first to use the ultrasound extended field of view (EFOV) technique to quantify bicep brachii CSA for an indication of muscle swelling, the reliability and validity of the technique were assessed in a separate study using 6 men (27.5 ± 1.9 y). In the main study, 10 non-resistance trained men (26.1 ± 4.1 y) performed two bouts of eccentric exercise of the elbow flexors for each arm (4 bouts in total). One arm performed 3 sets of 10 maximal eccentric contractions (3x10) followed 4 weeks later by 20 sets of 3 maximal eccentric contractions (20x3). The contralateral arm performed 10 sets of 3 maximal eccentric contractions (10x3) followed 4 weeks later by 20x3. The order of the exercise (3x10, 10x3) and the use of arm (dominant, non-dominant) were counterbalanced amongst subjects. Changes in the criterion measures over time and peak torque were compared among the initial bouts (3x10 vs. 10x3) and the repeated bouts (20x3 vs. 20x3) by a factorial repeatedmeasures analysis of variance (ANOVA) with two factors. Significance level was set at P

Grantor dc:publisher

Edith Cowan University, Research Online, Perth, Western Australia

Year dc:date

2011

Author dc:creator

• Chan, Roy Y.H.

• maximal voluntary contraction strength
• creatine kinase
• muscle soreness
• ultrasound extended field of view
• cross sectional area
• biceps brachii
• Sports Sciences

Repository record dc:identifier

https://ro.ecu.edu.au/theses/382

OAI identifier oai:identifier

oai:ro.ecu.edu.au:theses-1382