The objective of this study was to investigate the relation between the number of series and duration of shoulder stretching exercises on the immediate and late acute effects on flexibility. Seventy individuals with ages ranging from 20 and 30 years with no previous flexibility training participated in this study. Randomly, 10 subjects composed the control group (CG) and the others were equally divided into three groups according to the duration of the stimulus, namely: 10 seconds (G10), 60 seconds (G60) and 120 seconds (G120). Later, each group was subdivided in relation to the number of series, namely: one (G10A, G60A, G120A) and three series (G10B, G60B, G120B). Flexibility was measured through an universal goniometer and the observations occurred shortly after, 90 minutes after and 24 hours after stimulation. The analysis of variance ANOVA identified significant association between the time of stimulus and the other variables (p = 0.042). No differences of flexibility were verified between experimental groups, but all groups exhibited values higher than CG. The temporal comparison of absolute values of flexibility for groups submitted to the same stimulus duration and number of series revealed significant differences only for G120A, G60B and G120B, between the first observation and 24 hours after. On the other hand, the analysis of the percentile values showed that the stimulation time and the number of series were associated with the duration of the flexibility acute increment. In this case, no differences between groups were verified, except between G60A and G60B in the observation after 24 hours. One concludes that stimulus duration may provide higher initial flexibility, regardless the number of series. However, the immediate gains of flexibility could not be maintained after 24 hours. No one knows, however, if progressive long-duration stimuli would provide long-term higher amplitude if compared with stretching exercises performed in shorter periods of time.
Training; Exercise; Physical fitness; Mobility; Joint
