The complexity of exercising in the fasted state
Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
The current study investigated the effects of 60 minutes of moderate exercise performed by endurance-trained men in the fed and the fasted state. The aim was to compare and evaluate the effects of the two trials, both during the 1-hour cycle ergometer test and also during the following 5,5-hour rest period. Seven healthy and well-trained men volunteered to participate in the study. Pre-testing with a maximal cycle-ergometer test was done to determine the workload prior to the main trials. Subjects arrived at the main experiments in the fasted state, and whether they were doing their fasted or fed state trial, they either received a small carbohydrate-rich meal or remained in the fasted state. They performed a cycle-ergometer test for 60 minutes with workloads ranging from 55-70% of their maximal performance during pre-testing and afterwards they received identical meals and remained in a resting position throughout the rest of the day. The current study measured FFA, RER, insulin, glucose, lactate, oxygen uptake (VO2), body temperature and heart rate. The concentrations of FFA were significantly higher during the exercise in the fasted state, mainly during the actual cycle ergometer test and 90 minutes post-exercise. There was no significant difference in the use of substrate (RER) between the two trials and the insulin concentration was significantly higher post-exercise during the fed trial. The glucose concentration was significantly higher during the fasted trial, mainly during the cycle ergometer test. There were no significant differences on body temperature, lactate, VO2 or heart rate. It is concluded that, even while having a significant FFA release during and immediately post-exercise, well-trained males does not gain any significant advantage in fat oxidation when performing moderate interval-based (55% to 70% VO2max) exercise in the fasted state.
Place, publisher, year, edition, pages
2010. , 14 p.
exercise, fasted state, fat oxidation
Sport and Fitness Sciences
IdentifiersURN: urn:nbn:se:umu:diva-55655OAI: oai:DiVA.org:umu-55655DiVA: diva2:528646
Svensson, Michael, Med dr, Lektor
Lorentzon, Ronny, Professor