Fat Use and Optimal Running Speed Study for Ultramarathons
This study, led by Christos Katsanos, PhD from Arizona State University, along with honors Kinesiology students Nathan Coury and John Kline (serving as their honors theses), aims to determine 1) If there is an optimal running speed where fat is the primary substrate used for energy and 2) If this optimal running speed is a better predictor of performance than VO2max. By measuring the ratio of fat versus carbohydrates used at a given speed either running or walking, we hope to determine the highest speed that a runner can travel at over a given distance while still using primarily fat as his or her main fuel source. We would like to recruit 15 male runners for this study, mainly to avoid complications with menstrual cycles, but future studies may include female subjects as well. Potential participants must also have completed a 50 mile or longer run in the past 5 years and be in a healthy condition.
The study will be conducted both in the lab and in the field. For the lab portion, subjects will be asked to come in on 4 separate occasions to the Clinical Research Unit exercise laboratory at Arizona State University Tempe campus. One session will be used to determine optimal walking speed (a sub-maximal test) and VO2max (a maximal test), and the other three days will be used to determine optimal running speed (a sub-maximal test), all performed on the treadmill. Lab tests will all be completed in the mornings, save special circumstances, but definitely between the hours of 8am-5pm Monday through Friday. For the field portion, subjects will participate in a 50 mile race on a flat 500-meter dirt track as a test of performance to validate lab findings. The race will take place in Buckeye, Arizona on November 20th starting at 7am. Free race entry will be given to all study participants. During both the lab and field tests, participants will eat an individually-determined standardized breakfast before each lab session and on race morning, use a heart rate monitor, use an accelerometer, a Rate of Perceived Exertion scale, and a non-invasive scale used to measure Body Mass Index (BMI). We will be taking an inventory of all food and fluid intake during the race, as well as assessing each subjects medical condition and rate of perceived exertion in 5 mile intervals.
Participation is voluntary and each subject is free to withdraw from the study at any time. There are no costs associated with participation. The risks associated with participation in this trial do not exceed the risks normally associated with participating in a 50 mile ultramarathon race. Your participation will help the ultra endurance running community at large by determining what the optimal speed to run ultramarathon races in order to maximize fat use and thus help runners to achieve their personal best performances, and to minimize problems associated with incorrect pacing. If we find that this optimal running speed is also a better indicator of performance in ultramarathon races than VO2max, this could mean hope for those who do not perform as well in shorter races because they may still be able to do well in longer ultramarathon events.
If you are interested in a chance to become a participant in this study, please send an email with “Ultramarathon Study” in the subject line to Nathan.Coury@asu.edu to receive more information.