The Relationship Between Lower-Body Flexibility and Running Performance in a Half Marathon Downhill Running Event.

Although previous studies examining treadmill or relatively flat overground running events have found relationships for running performance and flexibility, no study has examined these outcomes during downhill events, including between sexes. Therefore, the purpose of this study was to determine if a relationship exists between lower body flexibility and running performance in recreational adult male and female distance runners competing in a downhill half marathon race. Recreational (n=11 male, n=19 female) adult distance runners completed this study. On the day prior to the race, participants performed a standardized warm-up, followed by determining their sit-and-reach flexibility. The next day, individuals ran their race and their performance scores were recorded using the race organizers website. Pearson correlation coefficients (r) were determined between race time and flexibility. Sex differences were determined using independent t-tests, with significance set at p<0.05. A significant relationship was observed across all participants for race performance and flexibility (r=0.42, p=0.01), but was not when separating out male (r=0.53, p=0.10) and female (r=0.32, p=0.19). Sex differences were observed for performance times (male: 6692.0±920.1 vs female: 7613.3±1073.5 sec., p=0.021, d=0.84), but not flexibility (male: 28.1±8.4 vs female: 32.9±10.8 cm, p=0.19, d=0.47). Flexibility is an important component of running performance, but may have less predictive ability by sex in downhill running performance in recreational runners.