Fiber Type Composition and Rate of Force Development in Endurance- and Resistance-Trained Individuals. Issue 9 (September 2019)

• Record Type: Journal Article
• Authors: Methenitis, Spyridon; Spengos, Konstantinos; Zaras, Nikolaos; Stasinaki, Angeliki-Nikoletta; Papadimas, Giorgos; Karampatsos, Giorgos; Arnaoutis, Giannis; Terzis, Gerasimos
• Is Part Of: Journal of strength and conditioning research. Volume 33:Issue 9(2019)
• Publication Date: 2019-09
• Subjects: skeletal muscle morphology -- muscle power -- resistance training -- endurance runners; Physical education and training -- Periodicals; Weight training -- Physiological aspects -- Periodicals; Physical fitness -- Periodicals; 613.7
• DOI: 10.1519/JSC.0000000000002150
• Languages: English
• ISSNs: 1064-8011

Abstract

Abstract : Abstract: Methenitis, S, Spengos, K, Zaras, N, Stasinaki, A-N, Papadimas, G, Karampatsos, G, Arnaoutis, G, and Terzis, G. Fiber type composition and rate of force development in endurance- and resistance-trained individuals. J Strength Cond Res 33(9): 2388–2397, 2019—The purpose of the study was to investigate the relationship between muscle fiber composition and the rate of force development (RFD) in well-trained individuals with different training background. Thirty-eight young men with different training background participated: 9 endurance runners, 10 power-trained individuals, 9 strength-trained individuals, and 10 sedentary individuals. They performed maximal isometric leg press for the measurement of RFD. Body composition (dual x-ray absorptiometry) and vastus lateralis fiber type composition were also evaluated. When all participants were examined as a group, moderate correlations were found between the percent of type II muscle fibers and RFD between 100 and 600 milliseconds ( r = 0.321–0.497; p ⩽ 0.05). The correlation coefficients were higher for the cross-sectional area (CSA) and the %CSA of type II and IIx muscle fibers ( r = 0.599–0.847; p < 0.001). For the power group, RFD up to 250 milliseconds highly correlated with % type IIx muscle fibers and type IIx fiber CSA ( r = 0.670–0.826; p ⩽ 0.05), as well as with %CSA of type IIx fibers ( r = 0.714–0.975; p ⩽ 0.05). Significant correlations were found between the relative RFD (·kg −1 lower extremities lean mass) and CSA-%CSA of type II and IIx fibers for the power group ( r = 0.676–0.903; p ⩽ 0.05). No significant correlations were found between muscle morphology and RFD for the other groups. In conclusion, the present data suggest that there is a strong link between the type IIx muscle fibers and early RFD and relative RFD in power-trained participants. Type II fibers seem to be moderately linked with RFD in non–power-trained individuals.