Arterial Compliance Decreases Following Ultra-Endurance Competition

Abstract

Listen

Translate article

It is well established that habitual aerobic exercise training is associated with an increase in arterial compliance. A small number of studies have examined the effects of an acute bout of aerobic exercise on measures of arterial compliance, with the conclusion that short duration exercise leads to an increased compliance. However, the response to prolonged ultra-endurance exercise is currently unclear. PURPOSE: To assess the change in arterial compliance following prolonged endurance exercise in healthy athletes with normal baseline measures. METHODS: Arterial compliance was measured non-invasively using applanation tonometery (CR-3000, HDI) at least 1 day prior to competition and approximately 30 min after completion of an ultra-endurance (120 km or 195 km) mountain trail running race. Radial arterial waveforms were collected from the right arm in conjunction with automated blood pressure on the left arm, allowing estimation of both large (capacitive arterial compliance) and small (oscillatory or reflective) artery compliance. Measures of pre- and post-race weight, seated blood pressure (BP) and heart rate were also recorded. Comparisons were made using paired t-tests and ANOVA to examine whether race distance or gender affected outcomes. Associations between race time (pace) and pre-post changes were examined using Pearson correlation. RESULTS: Race completion took approximately 25.8 ± 3.5 hr and 37.4 ±4.3 hr to complete the 120 and 195 km courses respectively with no significant difference in average pace between distances. Mean systolic and diastolic BP were maintained pre- to post-race, despite a significant decrease (4.6 ± 15.9 kg) in weight, likely reflecting fluid loss. A moderate relationship (r = 0.49, p = 0.027) existed between decreases in systolic BP and increasing age. There was no significant change in small artery compliance; however, large artery compliance decreased from 16.1 ± 4.4 to 13.6 ± 3.8 mL/mmHg × 10. CONCLUSION: Participation in prolonged ultra-endurance running led to acute decreases in arterial compliance. Further research is required to determine the effects of these changes on cardiovascular function and health.