The Muscle Morphology of Elite Sprint Running

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 assess the relationships of muscle volumes and strength with sprint performance. Methods: Five elite sprinters (100 m seasons best [SBE100]: 10.10 ± 0.07 s), 26 sub-elite sprinters (SBE100: 10.80 ± 0.30s) and 11 untrained control participants underwent: 3T magnetic resonance imaging scans to determine the volume of 23 individual lower limb muscles/compartments and 5 functional muscle groups; and 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 SBE100), 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 (TFL, sartorius, gluteus maximus; absolute +45-57% and relative volume +25-37%), and gluteus maximus volume alone explained 34-44% of the variance in SBE100. Isometric strength of several muscle groups was greater in both sprint groups than controls, but similar for the sprint groups and not related to SBE100. 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.

Muscle size of individual hip extensors in sprint runners: Its relation to spatiotemporal variables and sprint velocity during maximal velocity sprinting

“…This result disagrees with previous findings [ 12 , 13 ] that GM volume was negatively correlated with 100 m sprint time. The reasons for the discrepancy between the present and previous results are not clear at this moment, but may be related to the difference in range of participants’ sprint performance: 10.35–11.33 s (present study) vs. 10.23–11.71 s (Sugisaki et al [ 12 ]) and 10.03–11.50 s (Miller et al [ 13 ]). In the previous study [ 13 ], GM volume was larger in the elite sprinters (sprint time: 10.03–10.21 s) than in the sub-elite sprinters (sprint time: 10.36–11.50 s).…”

“…The reasons for the discrepancy between the present and previous results are not clear at this moment, but may be related to the difference in range of participants’ sprint performance: 10.35–11.33 s (present study) vs. 10.23–11.71 s (Sugisaki et al [ 12 ]) and 10.03–11.50 s (Miller et al [ 13 ]). In the previous study [ 13 ], GM volume was larger in the elite sprinters (sprint time: 10.03–10.21 s) than in the sub-elite sprinters (sprint time: 10.36–11.50 s). Thus, GM size may be important for achieving shorter sprint time than that of the present participants.…”

“…Therefore, it is speculated that size of muscle(s) which contribute greatly to sprinting is related to sprint performance, whereas that of the other hip extensors is not. In this regard, several studies demonstrated that the sizes of GM [ 12 , 13 ], thigh adductors [ 14 – 16 ], and hamstrings [ 12 , 15 ], relative to body mass were significantly correlated with sprint velocities (or times). However, previous studies [ 12 , 15 ] evaluated the size of hamstring muscle group as a whole, although the group is actually comprised of three muscles (but delineated by four names: the semitendinosus [ST], the semimembranosus [SM], the biceps femoris long head [BFlh], and the biceps femoris short head [BFsh]).…”

“…Therefore, the contributions of the individual hamstring muscles to sprint performance may be variable among them. For example, ST volume was larger in sprinters than in non-sprinters [ 11 , 13 ], and the magnitude of the difference (54%) was substantially greater than those in the other hamstrings (20–26%) [ 11 ]. Furthermore, mechanisms underlying the relationship between the hip extensor size and sprint velocity remain unknown.…”

“…The purpose of the present study was to examine the relationships between the sizes of individual hip extensors, the spatiotemporal variables, and sprint velocity during maximal velocity sprinting. It was reported that GM volume was correlated with sprint time [ 12 , 13 ]. Among the hamstrings, the ST displayed the longest fiber length [ 17 ], which is a determinant of the maximal shortening velocity of the muscle [ 18 ] and affects the force-velocity relationship [ 19 ].…”