Abstract details
| Abstract-ID: | 1936 |
| Title of the paper: | The rate of force development as a determinant of maximal theoretical velocity in the force-velocity relationship |
| Authors: | Boccia, G.1,2, Brustio, P.R.1,2, Salvaggio, F.3, Pintore, A.1,2, Grossio, L.1, Calcagno, E.1, Rainoldi, A.2,4, Samozino, P.5 |
| Institution: | 1 Neuromuscular Function research group, School of Exercise and Sport Science, University of Turin, Italy 2 Department of Clinical and Biological Sciences, University of Turin, Italy 3 Department of N |
| Department: | Department of Clinical and Biological Sciences, University of Turin |
| Country: | Italy |
| Abstract text | INTRODUCTION: Rate of Force development (RFD) calculated at 50 and 100 ms represents the capacity to quickly produce force starting from a relaxed state during isometric contractions. The theoretical maximal velocity obtained from force-velocity (FV) relationship (V0) represents the capacity to produce force at high velocity during dynamic contractions. While these two capacities are intuitively close, their association has not been studied so far. We thus investigated the role of RFD and maximal voluntary force (MVF) on the theoretical maximal velocity (V0) and force (F0) of the knee extensors. METHODS: Single-leg knee extensors were tested under isometric and dynamic conditions in 44 young adults (15 females). Participants performed two 5-s maximal isometric contractions to calculate MVF and 10 isometric burst-like contractions to compute RFD at 50, 100, and 150 ms and at peak. Then, a set of incremental-load knee extension maximal efforts were performed on a modified knee-extension isoinertial ergometer. Force and velocity were continuously measured and averaged over 80-to-140° knee angles to determine individual hyperbolic FV relationships. RESULTS: FV relationships were well fitted by hyperbolic regression (r˛ from 0.983 to 0.993). Stepwise linear regression showed that isometric RFDpeak normalized to MVF was the main determinant of V0 (R2 = 0.157, P = 0.006) while MVF was the main determinant of F0 (R2 = 0.362, P < 0.001). Correlation analysis showed that RFD at 50ms (R = 0.418, P = 0.003) and RFD at 100 ms (R = 0.313, P = 0.028) correlated with V0, while RFD 150 ms correlate with F0 (R = 0.583, P < 0.001). The curvature of the FV relationship did not correlate with any RFD or MVF indexes. CONCLUSION: When obtained from averaged values over knee extension, V0 (and not F0) is partially explained by muscle contraction quickness (i.e.“explosive” force capacity). So, the capacity to produce force at high velocity partly depends on the capacity to rise quickly the force in the early phase of the contraction, suggesting that some underlying determinants of RFD would also affect V0. |
| Topic: | Training and Testing |
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