Vascular adaptation in elite female and male rowers across a competitive season

The 'athlete's artery' phenotype describes exercise-induced vascular adaptation whereby athletes have enlarged conduit arteries resulting from chronic endurance exercise. However, studies remain limited to males, with few evaluating changes in response to training. This study aimed to compare upper and lower limb adaptations across a 21-week competitive season between elite female and male rowers. Twenty-one athletes (females n = 10) were assessed at three timepoints across a 21-week season: early- (ES), mid- (MS), and late-season (LS). High-resolution duplex ultrasonography assessed brachial and femoral artery diameter, flow-mediated dilation (FMD%), and ischaemic hand-grip exercise (vasodilatory capacity, VD%). Data was analysed using Bayesian repeated measures ANOVA (training × sex). The time-course for peak brachial diameter differed for sex with largest diameter for females at LS (4.3 ± 0.3 cm) compared to MS for males (5.1 ± 0.3 cm). Similarly, brachial FMD% differed by sex with training where females had largest FMD% at LS and males at MS. However, shear-normalised brachial FMD% showed no effect of training or sex. No changes in VD% were observed. Femoral artery diameter was larger in males, while no sex or training effects were evidence for femoral FMD%. In the upper limb, brachial diameter increased with training which differed by sex, suggesting a sex-specific response. While brachial FMD% also improved with training in each sex, normalising for shear rate removed all apparent differences, suggesting a shear-mediated response. Lower limb vasculature was less impacted by training, with a moderate effect for sex.