ABSTRACT
CONTENTS Introduction .........................................................................................................283 Acute HDL-C and HDL-C Subfraction Changes with Exercise .................284 Changes in Blood Triglycerides after Exercise ..............................................285 Post-Exercise Changes in Total Cholesterol and LDL Cholesterol.............290 Lipoprotein (a) after Exercise ...........................................................................291 Apolipoproteins and Exercise-Induced Changes ..........................................291 Mechanisms for Changes in Blood Lipids and Lipoproteins
Following Exercise.....................................................................................292 Other Exercise Considerations for Lipid Benefit...........................................293 Summary ..............................................................................................................294 References ............................................................................................. 295
Under normal fed conditions in humans, lipids stored in muscle and circulating in blood are an important source of energy to perform physical exercise. The proportion of energy coming from oxidation of lipids, primarily fatty acids, during exercise is a function of the work intensity. At relatively low to moderate intensities (< 65% VO2max), lipid oxidation may supply more than half of the energy required by exercise, but at higher intensities most energy is provided through oxidation of carbohydrate.1 Regardless of the energy source during exercise, lipids are the predominant fuel oxidized during recovery from exercise. Thus an acute change in blood (and muscle) lipid concentrations is a natural consequence of the use of this energy source for the work of physical exercise. This is especially the case when the work
demands of exercise can be met predominantly by aerobic means. Furthermore, metabolic, hormonal, and physiologic effects of a single session of exercise, especially intense and prolonged exercise, may take hours or days from which to fully recover. For example, muscle insulin sensitivity, glucose transport, and uptake of blood triglycerides (TG) are increased for at least several hours after a single session of exercise.2,3 Thus, a rationale for acute changes in blood lipid concentrations is firmly based on known exerciseinduced changes in fuel metabolism.
