The Muscle Morphology of Elite Sprint Running

Abstract

ABSTRACT The influence of muscle morphology and strength characteristics on sprint running performance, especially at elite level, is unclear. Purpose This study aimed to investigate the differences in muscle volumes and strength between male elite sprinters, sub-elite sprinters, and untrained controls and to assess the relationships of muscle volumes and strength with sprint performance. Methods Five elite sprinters (100-m season’s best equivalent [SBE 100 ], 10.10 ± 0.07 s), 26 sub-elite sprinters (SBE 100 , 10.80 ± 0.30 s), and 11 untrained control participants underwent 1) 3-T magnetic resonance imaging scans to determine the volume of 23 individual lower limb muscles/compartments and 5 functional muscle groups and 2) isometric strength assessment of lower body muscle groups. Results Total lower body muscularity was distinct between the groups (controls < sub-elite +20% < elite +48%). The hip extensors exhibited the largest muscle group differences/relationships (elite, +32% absolute and +15% relative [per kg] volume, vs sub-elite explaining 31%–48% of the variability in SBE 100 ), whereas the plantarflexors showed no differences between sprint groups. Individual muscle differences showed pronounced anatomical specificity (elite vs sub-elite absolute volume range, +57% to −9%). Three hip muscles were consistently larger in elite vs sub-elite (tensor fasciae latae, sartorius, and gluteus maximus; absolute, +45%–57%; relative volume, +25%–37%), and gluteus maximus volume alone explained 34%–44% of the variance in SBE 100 . The isometric strength of several muscle groups was greater in both sprint groups than controls but similar for the sprint groups and not related to SBE 100 . Conclusions These findings demonstrate the pronounced inhomogeneity and anatomically specific muscularity required for fast sprinting and provides novel, robust evidence that greater hip extensor and gluteus maximus volumes discriminate between elite and sub-elite sprinters and are strongly associated with sprinting performance.