Objective: Training has different adaptive effects on muscle architecture and body types in the long term. The purpose of this study was to compare rectus femoris architecture and somatotypes of well-trained bodybuilders and soccer players.
Material and Methods: A total of thirty male athletes (15 bodybuilders and 15 soccer players, with at least 5 years of training experience) were included in the study. The thickness of the rectus femoris muscle (MT), pennation angle (PA), and fascicle length (FL) were measured using B-mode ultrasound and somatotyping has been performed by the Heath-Carter method.
Results: PA (19.1%, p=0.007) and MT (11.5%, p=0.039) were greater in bodybuilders than soccer players, while FL was similar (5%, p=0.220) between athletes. A moderate effect size (ES) was found at MT (ES = 1.06; 95% CI) and a large ES at PA (ES = 1.55; 95% CI). Somatotyping has revealed that bodybuilders were endomorphic mesomorph (3.01-5.74-2.05) and soccer players were mesomorph-ectomorph (2.52-3.58-3.80).
Conclusion: Training affects muscle morphology and somatotype of athletes with regard to sport specific training patterns in long term. Revealing the adaptive characteristics of muscle architecture and somatotypes may help sports scientists and coaches in train planning and modification.