Effect of Pre-Exercise Nutrition on Human Skeletal Muscle UCP3 Expression

Authors

Elisa Morales, Baylor UniversityFollow
Jeffrey S. Forsse, Baylor UniversityFollow
Thomas Andre, Baylor UniversityFollow
Sarah K. McKinley, Baylor UniversityFollow
Paul Hwang, Baylor UniversityFollow
Grant Tinsley, Baylor UniversityFollow
John Davis, Baylor UniversityFollow
Mike Spillane, University of South AlabamaFollow
Peter GrandjeanFollow
Darryn Willoughby PhD, Baylor UniversityFollow

Abstract

BACKGROUND: Increased UCP3 expression in skeletal muscle after exercise may be attributed to elevated free fatty acids (FFA) that are known to directly activate UCP3 expression. Pre-exercise glucose consumption has shown to blunt UCP3 expression in response to exercise. Since glucose ingestion before and during exercise is typically not a common practice, the goal of the present study was to assess the effect of a multi-macronutrient meal (drinkable shake) in the pre-exercise period towards human skeletal muscle UCP3 expression. METHODS: Using a crossover design, untrained participants performed an endurance exercise session (350 kcal at 70% of their VO₂max) after two experimental conditions 1) consumption of a multi-macronutrient meal and 2) a fasting period of 8 h. Blood samples were taken at baseline, pre-exercise, post-exercise, 1h, and 4h post-exercise, while muscle biopsies were taken at the last four time points. RESULTS: A significant increase in FFA was observed in the fasting condition (p= 0.046) as well as a significant increase in UCP3 mRNA and protein expression at post-exercise (p= 0.042) and 4 h post-exercise (p= 0.036) respectively, in the multi-macronutrient meal condition. DISCUSSION: Variables showed a total opposite response to what has been reported after the consumption of pure glucose before an exercise session. Instead of observing a decrease in UCP3 expression in the non-fasting condition, we observed a significant increase in UCP3 mRNA and protein concentration in the multi-macronutrient condition. According to previous research, variables such as the protein and fat content from the multi-macronutrient meal, as well as the insulin levels, could have played key roles in altering UCP3 mRNA and protein expression in the multi-macronutrient condition; however, further research is needed to confirm this hypothesis. CONCLUSION: The expression of UCP3 mRNA and protein expression as a result of exercise might be controlled by factors other than FFA.

Recommended Citation

Morales, Elisa; Forsse, Jeffrey S.; Andre, Thomas; McKinley, Sarah K.; Hwang, Paul; Tinsley, Grant; Davis, John; Spillane, Mike; Grandjean, Peter; and Willoughby, Darryn PhD (2016) "Effect of Pre-Exercise Nutrition on Human Skeletal Muscle UCP3 Expression," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 8, Article 73.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss8/73