director of endurance study
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David Swanson, Exercise Physiology,
director of endurance study |
The Heart of the Matter
Student-centered research is at its best when it generates future research questions for other graduate students. This has certainly been the case for our pycnogenol study. Pycnogenol is a broad-based antioxident extracted from the bark of a pine tree in southern France. Our hypothesis, based on the work of Michael Ried, associate professor of medicine, Baylor College of Medicine, began with the concept that strenuous exercise oxidants accumulate in muscle tissue and accelerate the fatigue process. We hypothesized that pycnogenol could enhance an athlete's endurance by functioning as an anti-oxident.
Barking up the Wrong Tree?
Doug Tirado, a graduate student in exercise physiology, Paul Pavlovic, an internist from Paradise, and I designed a double-blind, placebo-controlled, crossover study to see if pycnogenol would enhance exercise endurance. (Tirado recruited the subjects, carried out the protocol, collected the data, and is writing the study up for his master's thesis.) Two groups of recreational athletes were put on either pycnogenol or a placebo for thirty days and then crossed over to either placebo or pycnogenol for another thirty days. Endurance time to exhaustion at 85 percent of their maximum workload was measured at base line, at thirty days, and at sixty days. Overall, there was a 21 percent increase in endurance when the subjects were on pycnogenol.
Since January, graduate students David Almo and Tom Ruthven and I have been investigating how the laboratory apparatus (metabolic cart, blood drawing kit, etc.) connected to the subjects may account for variability in their response and, thus, may enhance a placebo response. It may be that if all this apparatus is removed, the placebo response will be minimized.
Out on a Limb
Although the results of our pilot study were not significant, we did see an effect of pycnogenol. Calculations indicate that if that effect is real (i.e., did not happen by chance) then a new study with a larger sample size should have sufficient power to identify pycnogenol's effects. We are now designing a new study that will minimize all of the inherent problems detected in our pilot study. Other studies will also extend into the exercise response at altitude (next summer's Olympic Games held in part at Park City, Utah, an altitude of 1,800 meters).
These future studies will present opportunities for other students to develop their research skills. Ruthven is now initiating his own study in older adults where he is looking for possible oxidative damage under moderate exercise bouts. Tirado is also initiating his own study investigating grape seed extract and its possible effect on fat absorption.
Our exercise physiology classes are involved in the data analysis and experimental design. Our epidemiology class (PHED 186) has considered the discrete variable analysis. Our graduate statistics class (PHED 301) has looked at the continuous variable analysis and the sample size design. Our environmental physiology class (PHED 380) has considered the experimental variability problem and the nature of the placebo effect.
KM