Scientists used new high-tech tools to identify changes in more than 20 metabolites that were associated with exercise, reflecting, for example, how the body turns various forms of stored fuel into energy. Many of those changes continued for an hour after exercise. There were differences between changes in fit and less-fit people; the fitter folks, for example, exhibited signs of stepped-up fat metabolism and fewer changes associated with oxidative stress. And there were some differences in the changes produced by a short exercise session and the marathon.
Findings from this study could prove useful in developing training programs to improve exercise performance and in developing interventions to reduce the effects of diabetes or heart disease, according to researchers.
Better understanding the mechanisms at work in the body during and after physical activity is a goal shared by a number of researchers, including some at Stanford. In 2006, cardiologist Euan Ashley, MD, led a study showing that the heart experiences fatigue and a temporary reduction in cardiac output during extreme endurance exercise.
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