Master's Student Texas A&M University College Station, Texas, United States
Purpose: The purpose of this study was to investigate the relationship between sprint momentum and time at different distances with playing time across different position groups. Methods: Subjects were participants in a NCAA Division 1 Power 5 football team over a 5-year period (n=266, 1.79± 0.22m, body mass= 102.4 ± 18.47kg, age=18.54 ± 1.72 years). Participants completed the 40-yard (40yd) dash as a part of standard testing procedures with the 10-yard (10yd) time being taken from the first 10-yards of the sprint. The sprint began in a three-point stance when the thumb was no longer in contact with the pad. The athlete ran 36.6m (40yards) and times were taken when the athlete crossed the 9.14m and 36.6m marks by a photocell optical laser. Momentum was then calculated by converting the sprint time into a velocity (36.6m/time) and then multiplied by the athletes’ body mass in kg. Athletes were grouped by position based on different physical requirements. Athletes were then analyzed further by classification of starter or non-starter for that season. Results: Repeated measures ANOVA found a statistically significant effect of change in momentum over time and playing time for both 10yd, F (2,5)=77.3, p(< .001) η²=.774 and 40yd, F(2,23)=143.279, p(< .001), η²= .626. A univariate ANOVA found that all three positions showed significant difference between starters and non-starters, see figure below. Conclusions: The 10yd and 40yd dash proved to have statistically significant differences between starters and non-starters for all three positions and similar effect sizes between the 10 and 40yd effect sizes. Effect sizes were larger in big and mid positions than in skill positions across both 10 and 40yd momentums. Practical Applications: With the similarity in effect size for the 10 and 40yd dash for both time and momentum, they could be used interchangeably at the coach’s discretion. The research team would recommend the use of the 10yd dash over the 40yd dash due to the lower number of gait cycles and lack of max velocity that could increase the risk of injury in the 40yd dash compared to the 10yd dash. The use of momentum tracking would also be recommended as the effect size was larger between the starters and non-starters than the effect size for the 10 and 40yd dash times. Acknowledgements: None
