Alterations in Lipid Metabolism and Exercise Performance During Passive Heat Exposure and Subsequent Exercise in the Heat

• Main Author: O'Hearn, Katharine
• Other Authors: Haman, Francois
• Language: en
• Published: Université d'Ottawa / University of Ottawa 2013
• Subjects: non-esterified fatty acids; hyperthermia; lipid metabolism; work capacity
• Online Access: http://hdl.handle.net/10393/23665; http://dx.doi.org/10.20381/ruor-6394

Heat exposure causes several physiological and metabolic alterations. Although lipids are vital in sustaining energy production, heat-induced alterations in lipid metabolism have not been clearly established. CHAPTER 1 reviews the known metabolic alterations resulting from heat stress, with a specific focus on changes in whole-body lipid utilization and plasma lipids. CHAPTER 1also outlines the physiological changes caused by heat stress, and their role in reducing exercise performance. The study presented in CHAPTER 2 has shown that, compared to thermoneutral conditions, NEFA concentrations were 37% higher following passive heating and 34% higher following exercise in the heat, without significant changes in whole-body lipid utilization. In addition, the level of hyperthermia attained during passive pre-heating and exercise in the heat resulted in a 13% decrease in total external work and a significantly higher rate of perceived exertion. CHAPTER 3 summarizes the study results and presents the limitations and applications of the study.