The sex difference in marathon running is increased with lower participation of women than men, but whether this occurs for ultramarathon running is not known. The study purpose was to determine whether the sex difference in performance widens among lower-placed runners and the association between the sex difference in running speed and participation rates. The top-10 ultramarathon running times, age at performance date, and the number of men and women finishers were analyzed from 20 races (45–160 km) in the US Track and Field Ultra Running Grand Prix. Men were faster than women for all events (18.7% ± 5.8%, P < .001). The sex difference in speed was the least for 100 km (14.9% ± 4.2%) and greatest for 45–50 km (19.3% ± 5.8%). The top-10 men were younger than the top-10 women (37.7 ± 3.2 and 39.0 ± 3.1 y, respectively, P < .001). The sex difference in speed increased with finishing place (1st place 15.6% ± 6.6% vs 10th 20.8% ± 5.6%, P < .001). Association analysis showed that the sex difference in speed was largest when there were fewer women than men finishers in a race; the strength of the association was greatest for the 80-km distance and least for the 160-km. Lower participation rates of women than men in the lower-distance ultramarathons and less depth among lower-placed women runners inflate the sex difference in ultramarathon performance.
Jonathon Senefeld, Carolyn Smith and Sandra K. Hunter
Sandra K. Hunter, Martin W. Thompson and Roger D. Adams
The purposes of this study were to investigate the rate of change with age of simple lower-limb reaction time (RT) in women and determine the relationship among RT. strength, and physical activity. Independent, community-dwelling women aged 20–89 years (N = 217) were assessed for knee-extension RT, maximal voluntary isometric contractions of the knee extensors (KE), and physical activity level. Trend analysis by ANOVA and regression analysis on RT were performed. Lower-limb RT increased and KE strength and physical activity level decreased linearly across age groups (p < .001). Active women had faster RTs than those of inactive women of the same age (p < .01). From multiple-regression analysis on RT, only 1 predictor variable. KE strength, emerged. Stronger women had faster RTs than those of weaker women (p < .0001), regardless of age and physical activity. Although RT was slower in older women, higher levels of strength and physical activity were associated with faster RTs in this group.