Men are more likely than women to slow in the marathon

Abstract

Studies on nonelite distance runners suggest that men are more likely than women to slow their pace in a marathon.

Purpose: This study determined the reliability of the sex difference in pacing across many marathons and after adjusting women's performances by 12% to address men's greater maximal oxygen uptake and also incorporating information on racing experience.

Methods: Data were acquired from 14 US marathons in 2011 and encompassed 91,929 performances. For 2929 runners, we obtained experience data from a race-aggregating Web site. We operationalized pace maintenance as the percentage change in pace observed in the second half of the marathon relative to the first half. Pace maintenance was analyzed as a continuous variable and as two categorical variables, as follows: "maintain the pace," defined as slowing <10%, and "marked slowing," defined as slowing ≥30%.

Results: The mean change in pace was 15.6% and 11.7% for men and women, respectively (P < 0.0001). This sex difference was significant for all 14 marathons. The odds for women were 1.46 (95% confidence interval, 1.41-1.50; P < 0.0001) times higher than men to maintain the pace and 0.36 (95% confidence interval, 0.34-0.38; P < 0.0001) times that of men to exhibit marked slowing. Slower finishing times were associated with greater slowing, especially in men (interaction, P < 0.0001). However, the sex difference in pacing occurred across age and finishing time groups. Making the 12% adjustment to women's performances lessened the magnitude of the sex difference in pacing but not its occurrence. Although greater experience was associated with less slowing, controlling for the experience variables did not eliminate the sex difference in pacing.

Conclusions: The sex difference in pacing is robust. It may reflect sex differences in physiology, decision making, or both.

Figure 1. Odd Ratios of Maintaining Pace and Marked Slowing

Forest plot for the odds of maintaining the pace (< 10% change in pace) (A) and marked slowing (≥ 30% change in pace) (B) for women relative to men. The error bars are 95% confidence intervals. The common estimate is the pooled odds ratio as estimated by the Mantel-Haenszel estimator. ‘Favors women’ indicates that women were less likely to slow than men. Conversely, ‘favors men’ means that men were less likely to slow than women.

Figure 2. Odd Ratios of Maintaining Pace

Forest plot for the odds of maintaining the pace (< 10% change in pace) for women relative to men with stratification for finishing time group and age group. The error bars are 95% confidence intervals. The common estimate is the pooled odds ratio as estimated by the Mantel-Haenszel estimator. The empirical logit estimator for the odds ratio was used when at least one sex category had no (or all) events (e.g., all men and women in the < 3 hour marathon finishing time group).

Figure 3. Odd Ratios of Marked Slowing

Forest plot for the odds of marked slowing (≥ 30% change in pace) for women relative to men with stratification for finishing time group and age group. The error bars are 95% confidence intervals. The common estimate is the pooled odds ratio as estimated by the Mantel-Haenszel estimator. The empirical logit estimator for the odds ratio was used when at least one sex category had no (or all) events (e.g., all men and women in the < 3 hour marathon finishing time group).

Figure 4. Percentage Change in Pace as a function of Finishing Time for Men and Women

A. LOESS smoothed curves modeling the relationship of percentage change in pace as a function of finishing times and for men and women who finished under 6 hours (n = 84,277). The points plotted are a random sample of 5000 finishers to provide context to the LOESS fitted lines. Women’s finishing times have been divided by 1.12 to account for VO_2max differences. B. LOESS smoothed curves modeling the relationship of percentage change in pace as a function of finishing times under 6 hours (n = 84,277) that are unadjusted and adjusted for physiological sex differences. Women, 10% adjustment indicates that women’s finishing times were divided by 1.10; Women, 16% adjustment indicates that women’s finishing times were divided by 1.16.