The pre-event preparation routine: The role of stretching
It is well known that both recreational and competitive athletes frequently perform some type of stretching exercise as part of their pre-event preparation routine. The rationale for stretching prior to the commencement of strenuous physical activity is most commonly related to perceptions of decreased injury risk and psychological based feelings of well being associated with undertaking a habitual routine. However, not only is the relationship between pre-event stretching, injury and/or athlete psychology yet to be scientifically established, this justification fails to consider the effect that the stretching may have on aspects of athletic performance. This is surprising, especially considering that optimum performance is generally the primary objective of most competitive sporting events. The notion that more thought should be given to the influence of pre-event stretching on subsequent athletic ability is further highlighted by the findings of recent research, which have suggested that static stretching, although historically the most common type of pre-event stretching, may actually be detrimental to performance by impairing the mechanical and/or neural function of the musculotendinous-unit (MTU). However, the practical application of these studies is limited due to the methodologies employed, which have frequently lacked relevance to most sporting events. Furthermore, the suggested benefits of an alternative method of pre-event stretching, known as dynamic stretching, remain anecdotal. Therefore, the purpose of this study was to examine the acute effects (magnitude and time-course) of sport-specific static and dynamic pre-event stretching protocols in order to determine their effect on measures of functional performance. Eighteen male subjects of an athletic background volunteered to participate in this research. The study involved a repeated measures design with the subjects performing each intervention in a randomised order on different days. The three different interventions were: 1) warm-up only (WUP), involving five-minutes of treadmill jogging; 2) warm-up plus static stretching (SS), involving five-minutes of treadmill jogging followed by eight-minutes of static stretching; and 3) warm-up plus dynamic stretching (DS), involving five-minutes of treadmill jogging followed by eight-minutes of dynamic stretching. A force-plate was used to measure subjects counter-movement jump (CMJ) height and drop jump (DJ) reactivity co-efficient immediately post-intervention (P0), and following a five-minute seated rest period (P5). No significant differences (P<0.05) in percent change scores were found between SS and WUP for either CMJ at P(-0.32%; ±5.35; P=0.82) and P0 5 (1.32%; ±7.04; P=0.47), or DJ at P(-0.62%; ±12.82; P=0.85) and P0 5 (3.04%; ±12.74; P=0.355). However, when differences between DS and WUP were compared, DS was observed to result in superior CMJ performance at P(3.71%; ±8.63; P=0.09) and P0 5 (3.69%; ±6.86; P=0.04), and DJ performance at P(7.68% ±16.87, P=0.08) and P0 5 (6.12% ±14.65, P=0.10). With regards to the time-course of the effects, no significant difference was observed between SS or DS after the five-minute rest period. Additional analysis also revealed a large ‘between-subject’ variation in response, indicating that the effect of pre-event stretching may vary substantially between individuals. While the non-significant effect of SS reported in the present study contradicts the majority of existing research, this finding provides evidence to suggest that the intensity and/or duration of sport-specific bouts of SS may be insufficient to induce any impairment in MTU function. Furthermore, the superior performance changes observed as a result of DS suggests that DS may represent a more appropriate form of preparation than that provided by traditional static stretching methods.