Normalmente nós sempre ouvidos dizer, falamos e aprendemos que o processo de aumento de força, nas primeiras semanas de treino, se dá em função dos ajustes neurais. Nesse sentido, a hipertrofia muscular só passaria a ser manifestada depois de 8 semanas de treinamento.
Acaba de sair um estudo que trás evidências diferentes:
Defreitas JM, Beck TW, Stock MS, Dillon MA, Kasishke PR 2nd. An examination of the time course of training-induced skeletal muscle hypertrophy. Eur J Appl Physiol. 2011 Mar 16. [Epub ahead of print]
Skeletal muscle hypertrophy is typically considered to be a slow process. However, this is partly because the time course for hypertrophy has not been
thoroughly examined. The purpose of this study was to use weekly testing to determine a precise time course of skeletal muscle hypertrophy during a
resistance training program. Twenty-five healthy, sedentary men performed 8 weeks of high-intensity resistance training. Whole muscle cross-sectional area (CSA) of the dominant thigh was assessed using a peripheral quantitative computed tomography scanner during each week of training (W1-W8). Isometric maximum voluntary contractions (MVC) were also measured each week. After only two training sessions (W1), the mean thigh muscle CSA increased by 5.0 cm(2) (3.46%; p < 0.05) from the pre-testing (P1) and continued to increase with each testing session. It is possible that muscular edema may have influenced the early CSA results. To adjust for this possibility, with edema assumedly at its highest at W1, the next significant increase from W1 was at W3. W4 was the first significant increase of MVC over P1. Therefore, significant skeletal muscle hypertrophy likely occurred around weeks 3-4. Overall, from the pre-testing to W8, there was an increase of 13.9 cm(2) (9.60%). These findings suggested that training-induced skeletal muscle hypertrophy may occur early in a training program.