Relationship between somatotype components and muscle fiber type

Abstract

Background and Study Aim. It is stated that genetic factors, lifestyle and demographic components affect the morphological properties of the muscle; moreover, there is a relationship between adiposity indicators and skeletal muscle. The aim of this study is to examine the relationship between the somatotype components and obesity markers and the percentage of the fast twitch fibril type of skeletal muscle.
 Material and Methods. Nine male students of sports sciences voluntarily participated in the study (age = 22 ± 3.24 years). By applying the isokinetic fatigue test protocol, which is a non-invasive method, the percentage of fast twitch fibril of the vastus lateralis muscle was estimated. Body fat ratio and somatotype body types of the participants were determined as indicators of obesity.
 Results. There was a high positive linear correlation between the obesity indicators (endomorphy and body fat ratio) and the percentage of fast twitch fibril (r=0.738; r=0.809, p<0.01 respectively). The variance between the endomorphy and body fat ratio expressing fatness and the fast twitch fibril percentage were found to be acceptable (54-65% explained variance). A moderate negative linear correlation was found between the ectomorphy and percentage of fast-twitch fibril (r= -0.674, p<0.05). Finally, a moderate positive but statistically insignificant linear correlation was found between the mesomorphy and the percentage of fast twitch fibril (r=0.623, p>0.05).
 Conclusion. The findings show that the total fatness level of the body and the percentage of fast twitch fibril are not independent parameters and have a positive effect on each other.