Sex Differences in Endurance Running

Abstract

In recent years, there has been a significant expansion in female participation in endurance (road and trail) running. The often reported sex differences in maximal oxygen uptake (VO 2max ) are not the only differences between sexes during prolonged running. The aim of this narrative review was thus to discuss sex differences in running biomechanics, economy (both in fatigue and non-fatigue conditions), substrate utilization, muscle tissue characteristics (including ultrastructural muscle damage), neuromuscular fatigue, thermoregulation and pacing strategies. Although males and females do not differ in terms of running economy or endurance (i.e. percentage VO 2max sustained), sex-specificities exist in running biomechanics (e.g. females have greater non-sagittal hip and knee joint motion compared to males) that can be partly explained by anatomical (e.g. wider pelvis, larger femur-tibia angle, shorter lower limb length relative to total height in females) differences. Compared to males, females also show greater proportional area of type I fibres, are more able to use fatty acids and preserve carbo-hydrates during prolonged exercise, demonstrate a more even pacing strategy and less fatigue following endurance running exercise. These differences confer an advantage to females in ultra-endurance performance, but other factors (e.g. lower O 2 carrying capacity, greater body fat percentage) counterbalance these potential advantages, making females outperforming males a rare exception. The present literature review also highlights the lack of sex comparison in studies investigating run-ning biomechanics in fatigue conditions and during the recovery process.

Modeling lactate threshold in young squad athletes: influence of sex, maximal oxygen uptake, and cost of running

“…Therefore, especially in heterogeneous samples as in the present study, endurance performance is strongly related to VO 2 peak . Likewise, the lower values observed in the young female compared to the male athletes are in accordance with previous studies and are likely related to body composition (i.e., greater percentage of body fat) and oxygen carrying capacity (i.e., lower hematocrit levels) (Besson et al 2022).…”

“…Further, female athletes showed lower C R values independent of the determination method. This is an interesting finding which contributes to the debate whether or not there are sex differences regarding C R (Besson et al 2022). While some authors argue that sex differences in C R disappear when expressed as relative intensities (i.e., as percentage of VO 2 peak or lactate threshold) (Fletcher et al 2013;Helgerud et al 1990), our data indicate that, at least in young athletes, females exhibit lower values whether expressed as absolute (C R fix) or relative (C R 80% Fig.…”

“…However, it must first be investigated whether the model is dependent on age, since only adult athletes have been studied so far (Støa et al 2020;Støren et al 2014). Further, potential differences between sexes need to be considered, as sex specific prerequisites such as body composition could influence physiological characteristics such as aerobic capacity (Besson et al 2022). In addition, the influence of the methods used to calculate C (model predictor) and LT2 (criterion) are unknown.…”

Gender and Age Differences in Performance of Over 70,000 Chinese Finishers in the Half- and Full-Marathon Events

“…This is the difference between men and women in gene expression in human skeletal muscle [40]. Furthermore, male athletes exhibit higher maximal oxygen uptake (VO 2 max) and anaerobic thresholds than females in long-distance running [41]; there is a positive correlation between VO 2 max and thermoregulatory ability [42]. Some articles have pointed out that in the non-competition training phase, men have longer training distances than women and have more weekly training sessions, so the running experience of male runners is higher than that of women [43]; the same goes for training differences for a half marathon [3].…”

Sex influence on muscle synergies in a ballistic force-velocity test during the delayed recovery phase after a graded endurance run

“…Surprisingly, only a few studies have investigated the endurance running-induced fatigue effects in women [ 14 ]. Compared to male runners in the acute recovery phase, females showed attenuated peripheral plantar flexor fatigue and a smaller decrease in maximal voluntary contraction (MVC) of knee extensors after ultra-endurance races [ 15 , 16 ].…”