BACKGROUND: Muscular stretching is frequently used in sports practice with the aim to increase muscular flexibility and joint range of motion as well as to reduce injury risks and to improve athletic performance. AIM: To analyze the acute effect of stretching with different times in the dynamic strength performance of lower and upper extremities in young men. METHODS: The sample was composed by 14 healthy male volunteers aged 23 ± 2 years, weight of 84 ± 10 Kg , height of 178 ± 7 cm, BMI of 26 ± 2 Kg/m2 and body fat of 11 ± 3 %. They were evaluated in a 10-maximum repetition test (10-RM) in three situations: no stretching (NS); after an 8-minute session of static stretching followed by specific warm-up (SS-8); and after 16-minute and specific warm-up before 10 RM test (SS-16). Tests were performed in bench press and 45º leg press exercises, and stretching was selected as to reach the musculature required in these exercises. RESULTS: There was significant reduction (p<0.001) of dynamic muscular strength of upper extremities in comparison to NS with SS-16 (9.2%) and between SS-8 (4.2%) and SS-16 (14.3%) to lower extremities. This difference was found in all tested conditions. CONCLUSION: Static stretching sessions before activities involving dynamic strength are able to negatively change performance in longer stretching periods.
stretching time; muscular strength; physical exercise
