Abstract
Recent data, especially related to the molecular structure of muscle tissue and the neurophysiological processes that control muscular speed and force have questioned the benefits of stretching exercises performed prior to dynamic physical activities such as sprinting or jumping. On the other hand strength exercises with various types of muscle contraction and different training loads have proven effective in developing running speed and jumping performance. The present work attempted to verify the hypothesis concerning the detrimental influence of stretching on running speed and anaerobic power of lower limbs, while confirming the benefits of strength exercises on these motor abilities. The main objective of the study was to evaluate the short-term effects of stretching and strength exercises on running speed and jumping performance in competitive basketball players. The results showed significant changes in all of six variables used to evaluate lower limb power and running speed. Vertical jump performance showed increased tendencies in a microcycle without stretching, yet with strength exercises focused on lower limb extensors and flexors. Take-off speed, maximal jump height, work output and power during this microcycle were significantly higher in comparison to a weekly cycle were stretching was incorporated in the warm-up and prior to testing. In the case of running speed, the 3 treatments revealed significant differences, yet once again strength exercises compared to stretching allowed reaching of faster times for the 5 and 20 m sprint, respectively.