Predictors of Performance during a 161 km Mountain Footrace

Training volume and cardiovascular dynamics influence endurance performance. However, there is limited information on the interplay between training volume, cardiovascular dynamics, and performance in ultra-marathon athletes. PURPOSE: We aimed to determine predictors of performance in finishers of the 2023 Western States Endurance Run (WSER). METHODS: Sixty participants who finished the race (49 males/11 females; mean age: 44.7 ± 9.6 y, range: 26–66 y; BMI: 22.7 ± 2.2 kg/m2) completed pre-race surveys including average training volume (AV) and peak training volume (PV), as well as resting cardiovascular measures including resting heart rate (RHR) and augmentation index (AIx), a measure of wave reflection characteristics. Based on WSER completion time, we calculated average running velocity (RV). We assessed associations among 22 variables using bivariate correlation analysis (Pearson’s Correlation for normally distributed data and Spearman’s Rank Correlation if normality was not met). Within our listed variables, normality was met in age and AV. Additionally, we completed multiple regression analyses for predictors. We present descriptive data as mean ± SD. RESULTS: Participants had an average RV of 6.33 ± 0.97 km/h (3.93 ± 0.6 mph), and reported an AV of 91.9 ± 24.5 km/wk (57.1 ± 15.2 miles/wk) and a PV of 141.0 ± 47.2 km/wk (87.6 ± 29.3 miles/wk). We observed significant associations between RV and age (r(58) = -0.57, p r(58) = 0.41, p r(58) = 0.34, p R2 = 0.37; F(3,56) = 12.4, pb1 = 0.013; t(56) = 2.57, p = 0.013), resulting in a 0.33 km/h increase in RV for every 25-km increase in AV. Last, significant relations existed between RV and AIx (r(58) = -0.30, p = 0.022); and RHR (r(58) = -0.26, p = 0.046). CONCLUSION: We found that (1) average weekly training volume is a significant predictor of performance in elite ultra-marathon athletes and (2) race performance was inversely associated with resting arterial wave reflection characteristics and heart rate

AGING IS NOT ASSOCIATED WITH DECREASED KIDNEY VASCULAR CONDUCTANCE IN ULTRA-MARATHON RUNNERS

BACKGROUND: Vascular conductance refers to the ease with which blood flows through arteries. Vascular conductance is reduced with aging due to impairments of vascular structure (i.e., arterial stiffness and wall thickening) and function. Reduction in renal blood flow demonstrates an increase in blood pressure (BP) which contributes to the pathogenesis of hypertension. Habitual exercise reduces age-related declines in vascular function. Whether chronic ultra-endurance training offsets age-associated reductions in vascular conductance is largely unexplored. Therefore, we evaluated associations between age and kidney vascular conductance in ultra-marathon runners aged 22-66 years. METHODS: Thirty-nine ultra-marathon runners competing in the 2023 Western States 100-mile Endurance Run were included in this analysis (33 M/6 F, 41 ± 10 years, BMI: 23 ± 2 kg/m2; mean ± SD). Kidney blood velocity in the renal and segmental arteries was measured in the decubitus position using a GE Logiq e ultrasound (3 - 5 mHz). We measured supine brachial and central blood pressure using SphygmoCor XCEL. Renal and segmental artery conductance were calculated as blood velocity divided by central mean BP (cm●s-1/mmHg). All data were normally distributed (Shapiro-Wilk test, ps \u3e 0.05). We conducted Pearson’s r correlations between age and kidney vascular conductance and kidney blood velocity with α set at ≤ 0.05. RESULTS: Central mean BP in our sample was 92 ± 8 mmHg. Age was not associated with renal (0.58 ± 0.13 cm●s-1/mmHg; r = -0.243, p = 0.137) or segmental (0.35 ± 0.08 cm●s-1/mmHg; r = -0.239, p = 0.160) artery vascular conductance. Similarly, when central BP was not accounted for, age was not associated with renal (53 ± 12 cm●s-1; r = -0.086, p = 0.603) or segmental (32 ± 7 cm●s-1; r = -0.055, p = 0.748) artery velocity. CONCLUSIONS: While additional data in a larger sample size and age-matched control participants are needed, our data indicate that age is not associated with reduced resting kidney vascular conductance or blood velocity in ultra-marathon runners

AGE-RELATED CARDIOVASCULAR HEALTH AMONG ELITE ULTRA-ENDURANCE ATHLETES

BACKGROUND: Aging is associated with increased cardiovascular (CV) disease risk which is partly attributable to increased blood pressure (BP) and central arterial stiffness. Regular exercise is recommended to slow CV aging, but it is unclear whether “extreme exercise”, such as ultra-endurance running (\u3e42.2 km), elicits the same CV benefits as lower-volume training. Therefore, the purpose of this investigation was to test the hypothesis that ultra-endurance running preserves CV health across the lifespan. METHODS: We measured supine BP with an automated brachial cuff and arterial stiffness (carotid-to-femoral pulse wave velocity [cfPWV]) with applanation tonometry (SphygmoCor XCEL, AtCor Medical) among 72 athletes (16F/56M; BMI: 22.6 ± 1.8 kg/m2) 1-3 days before they competed in the 161-km Western States Endurance Race (WSER) (Olympic Valley, CA; elevation: 1890 m). We present data as mean ± SD and confirmed normality using Shapiro-Wilk tests (α ≥ 0.05). We used simple linear regression to assess the relationship between age and systolic BP (SBP), diastolic BP (DBP), and cfPWV. We compared individual cfPWV outcomes to available normative data. RESULTS: Among 72 WSER athletes, age (46 ± 10 years; range: 26-69 yrs), SBP (129 ± 9 mmHg), DBP (78 ± 7 mmHg), and cfPWV (n = 70; 6.5 ± 1.0 m/s) were normally distributed (Ws ≥ 0.97, Ps ≥ 0.06). Approximately 60% (43/72) of the athletes presented with hypertension (≥130mmHg SBP and/or \u3e80 mmHg DBP) but age was not associated with SBP (R2 = 0.02, P = 0.23) or DBP (R2 = 0.05, P = 0.06). Age was positively associated with cfPWV (R2 = 0.25, P \u3c 0.001) but 84% (59/70) of participants had cfPWV values below their age-predicted value (mean difference: -0.9 m/s). CONCLUSIONS: Among these WSER athletes, a majority were hypertensive, but there was not a meaningful relationship between age and BP. Moreover, in this sample, the increase in SBP per decade (1.3 mmHg/decade) was much lower compared to previously reported increases among the general population (6.5 mmHg/decade). Despite an age-related increase in cfPWV, 84% of athletes had cfPWV values below their age-predicted value. These findings suggest that ultra-endurance training is associated with preserved CV health across the lifespan via attenuated age-related increases in BP and cfPWV values below age-predicted norms