Males and Females Pace Differently in High School Cross-Country Races.

Deaner, RO and Lowen, A. Males and females pace differently in high school cross-country races. J Strength Cond Res 30(11): 2991-2997, 2016-Previous studies have demonstrated that men are more likely than women to slow in the marathon, but it is unknown whether the sex difference in pacing occurs for other race distances. This study addressed this question by analyzing the 5-km Virginia State Championship high school cross-country race for the years 2010, 2012, 2013, and 2014, which encompassed 3,948 performances. The pacing measure was percentage change in speed from mile 1 to mile 2. Across all runners, women (9.1%) slowed significantly (p = 0.002) more than men (8.7%), although the magnitude of the difference was trivial (effect size [ES] = -0.10). However, when women and men in physiologically equated finishing time groups (e.g., <17:00 for men; <19:03 for women) were compared, men slowed significantly more (p < 0.001) in all 4 groups, and the differences were nontrivial (ESs range 0.27-0.92). Because glycogen depletion is irrelevant for 5 km performances, these results challenge the hypothesis that the sex difference in pacing is due to males' greater susceptibility to glycogen depletion. These results instead support the hypothesis that the sex difference in pacing partly reflects a sex difference in some aspect of decision making, such as overconfidence, risk perception, or willingness to tolerate discomfort. Coaches and athletes are advised to consider individual variation in these characteristics when planning training and racing.