Peak oxygen uptake during running and arm cranking normalized to total and regional skeletal muscle mass measured by magnetic resonance imaging

The purposes of our study were to determine the peak oxygen uptake (V(.) >O(2peak)) per total or regional skeletal muscle (SM) mass using magnetic resonance imaging (MRI) and to investigate the relationships between SM mass and V(.) >O(2peak) during running and arm cranking. Eight male college swimmers aged 18-22 years [mean (SD) age 20.0 (1.3) years] were recruited to participate in this study. V(.) >O(2) during running and arm cranking were measured using an automated breath-by-breath mass spectrometry system. Contiguous MRI slices were obtained from the first vertebra cervicale to the malleolus lateralis (1.0-cm slice thickness, 0-cm inter-slice gap), resulting in a total of approximately 156 images for each subject. The absolute V(.) O(2peak) and the V(.) O(2peak) per body mass during running and arm cranking were 3.6 (0.6) l.min(-1), 54.4 (5.9) ml.min(-1).kg(-1) and 2.5 (0.5) l.min(-1), 36.9 (5.3) ml.min(-1).kg(-1), respectively. The absolute V(.) O(2peak) was higher ( P