Multivariate analysis in the maximum strength performance

Autor: André Yui Aihara, Valmor Tricoli, E. O. de Souza, Anderson Caetano Paulo, Manoel Neves, Carlos Ugrinowitsch, Carla Silva-Batista, Gilberto Cândido Laurentino, Ronaldo Kobal Cardoso, A. V. N. Bacurau, Patricia Chakur Brum
Rok vydání: 2012
Předmět:
Zdroj: International journal of sports medicine. 33(12)
ISSN: 1439-3964
Popis: This study performed an exploratory analysis of the anthropometrical and morphological muscle variables related to the one-repetition maximum (1RM) performance. In addition, the capacity of these variables to predict the force production was analyzed. 50 active males were submitted to the experimental procedures: vastus lateralis muscle biopsy, quadriceps magnetic resonance imaging, body mass assessment and 1RM test in the leg-press exercise. K-means cluster analysis was performed after obtaining the body mass, sum of the left and right quadriceps muscle cross-sectional area (∑CSA), percentage of the type II fibers and the 1RM performance. The number of clusters was defined a priori and then were labeled as high strength performance (HSP 1RM ) group and low strength performance (LSP 1RM ) group. Stepwise multiple regressions were performed by means of body mass, ∑CSA, percentage of the type II fibers and clusters as predictors’ variables and 1RM performance as response variable. The clusters mean±SD were: 292.8±52.1 kg, 84.7±17.9 kg, 19 249.7±1 645.5 mm 2 and 50.8±7.2% for the HSP 1RM and 254.0±51.1 kg, 69.2±8.1 kg, 15 483.1±1 104.8 mm 2 and 51.7±6.2%, for the LSP 1RM in the 1RM, body mass, ∑CSA and muscle fiber type II percentage, respectively. The most important variable in the clusters division was the ∑CSA. In addition, the ∑CSA and muscle fiber type II percentage explained the variance in the 1RM performance (Adj R 2 =0.35, p=0.0001) for all participants and for the LSP 1RM (Adj R 2 =0.25, p=0.002). For the HSP 1RM , only the ∑CSA was entered in the model and showed the highest capacity to explain the variance in the 1RM performance (Adj R 2 =0.38, p=0.01). As a conclusion, the muscle CSA was the most relevant variable to predict force production in individuals with no strength training background.
Databáze: OpenAIRE