Muscle Volume Gain Following 20 Training Sessions on an Eccentric Arm-Crank Ergometer

Eccentric resistance training is a promising strategy for achieving physiological benefits at lower cardiovascular and metabolic costs compared to traditional concentric training. Whereas lower-body eccentric training has been studied extensively, only little is known regarding upper-body eccentric strength training. This study assessed the impact of an eccentric arm-crank training on arm muscle volume. A total of 20 eccentric arm-crank training sessions were completed over a maximum of 12 weeks (2-3 trainings/wk). A training progression from 20 to 50% of the individual peak power and a duration from 8 to 14 minutes was applied. Before ("pretest") and after the training intervention phase ("posttest"), volume measurements using magnetic resonance imaging and circumference measurements of the upper arm were performed. Differences between pretest and posttest measurements were evaluated. Twelve healthy and physically active participants (median [Q1-Q3] age 28 [27-30] yr, nine females, three males) were included in the analysis. Relative muscle volume (+5.7%, <i>p</i>=0.002) and arm circumference (+3.2%, <i>p</i>=0.003) increased after the training intervention. Twenty eccentric arm-crank training sessions increased the muscle volume of the upper arm. Because eccentric training is associated with lower cardiovascular and metabolic demands, it is an attractive approach to improve upper-body strength. This training approach is especially interesting for individuals who rely on their upper body for daily activities, including wheelchair users. In the next step, the training protocol could be evaluated in this population across both rehabilitation and athletic settings.