Newswise — San Diego (April 3, 2016)—Between changes in elevation, terrain and weather, athletes who compete in mountain ultra-marathons can expect an extreme test of endurance and grit while running these 50-kilometer (~31 miles) races. But is there a way to predict the type of athlete that will post the best finishing time? New research presented today at the Experimental Biology 2016 meeting in San Diego suggests that a runner’s pre-race anaerobic fitness capacity may be a key factor in determining who will have the fastest finishing times.

Researchers at Simon Frasier University (SFU) in British Columbia observed two measures of fitness among the mountain marathoners: aerobic and anaerobic capacity. Aerobic fitness refers to how the body uses energy when there is enough oxygen, such as the energy burn that occurs when running at a comfortable pace. Anaerobic fitness refers to the body’s ability to exercise when there’s not enough oxygen, such as during a sprint to the finish line at the end of a race.

The research team assessed 10 healthy male mountain marathon competitors of similar age, weight and height. Aerobic capacity was measured by having the subjects run to the point of exhaustion on a treadmill, while anaerobic capacity was assessed through seated cycling ergometer.

“All our participants finished the race. The regression results indicated that those with higher anaerobic capacity were predicted to have a faster finishing time. This prediction of race finishing time was significant at a 5 percent level and explained 54 percent of the variance in finishing times,” said Michael Rogers, a member of the SFU research team. However, he added that the findings suggest the need for further research to explain the remaining 46 percent variance in finishing results.

The results suggest that these runners should aim to increase their anaerobic capacity in addition to their aerobic capacity, which is an established predictor of mountain ultra-marathon performance. “Typically, anaerobic capacity can be improved with high-intensity, shorter-duration training, such as in repetitive uphill sprint training,” Rogers said. The team also made a new observation: High-intensity efforts at greater than about 80 to 85 percent of maximal age-predicted heart rates can be being maintained for several hours in these mountain ultra-marathons. This is novel because “these are races that are typically thought to be performed at considerably lower exercise intensities,” he added.

Rogers, a graduate student at Simon Fraser University, will present “Prediction of Mountain Marathon Performance with Anaerobic Capacity” as part of the poster session “Acute Exercise Responses” Sunday, April 3, from 12:45 to 3 p.m. PDT in Exhibit Halls A-D of the San Diego Convention Center.

NOTE TO JOURNALISTS: To schedule an interview with a member of the research team, please contact Stacy Brooks at [email protected] or (301) 634-7209.

Full Abstract

PURPOSE: Anaerobic capacity, aerobic capacity and morphology were assessed for their potential effects on race performance during a 50 km mountain ultramarathon. HYPOTHESIS: It was hypothesized that anaerobic and aerobic capacities would be the best predictors of finishing times in this ultramarathon. METHODS: Ten healthy males were recruited to participate in this study. Their average height was 1.76±0.09 m, body mass was 70.75±8.04 kg, Body Mass Index was 22.9±1.85 kg·m2, body fat percentage was 21.98±4.75 %, and age was 47.6±11.0 years. The office of research ethics at SFU approved the study and each volunteer gave a signed consent prior to participation. Each volunteer’s anaerobic capacity was evaluated using a Wingate test on a seated cycle ergometer and aerobic capacity was assessed by indirect calorimetry with a breath-by-breath metabolic cart during an incremental test from rest to the point of exhaustion on a treadmill. Predictions of race finishing times were assessed using both stepwise multiple linear regression as well as ANCOVA with body mass as the covariate. The independent variables included mean power, peak power, minimum power, time to peak power, time to fatigue, body fat percentage, body mass, lean body mass and maximal oxygen consumption (VO2MAX). RESULTS: During the Wingate test mean power was 531.70±88.92 W, peak power was 854.30±193.97 W, time to peak power was 3.25±2.44 s and rate to fatigue was 18.01±4.93 s. During the incremental treadmill test VO2MAX_ABS was 4.01±0.65 L·min1 and VO2MAX_REL was 56.70±6.24 L·min1·kg body mass1. The stepwise multiple linear regression indicated that peak power (R2=0.59, p<0.05) or residuals from peak power plotted as a function of body mass (R2=0.54, p<0.05) were significant predictors of race performance in this mountain marathon. CONCLUSION: These preliminary results support that in a mountain ultramarathon a significant fraction of the variance in performance is predicted by peak power as determined in a Wingate anaerobic test.

About Experimental Biology 2016Experimental Biology is an annual meeting comprised of more than 14,000 scientists and exhibitors from six sponsoring societies and multiple guest societies. With a mission to share the newest scientific concepts and research findings shaping clinical advances, the meeting offers an unparalleled opportunity for exchange among scientists from across the United States and the world who represent dozens of scientific areas, from laboratory to translational to clinical research.

About the American Physiological Society (APS)APS is a nonprofit organization devoted to fostering education, scientific research and dissemination of information in the physiological sciences. The Society was founded in 1887 and today represents more than 11,000 members and publishes 14 peer-reviewed journals.