title: The influence of the intensity of treadmill walking upon changes in lipid and lipoprotein variables in healthy adults.
abstract: The purpose of the present study was to compare the acute and delayed effects of low- and moderate-intensity exercise on serum lipoprotein concentrations. Twelve healthy volunteers (five men, seven women), aged 28 (2) years [mean (SEM)], maximal oxygen uptake (VO2max) 48 (3) ml.kg-1.min-1 walked on a treadmill for 90 min, on two separate occasions, in a balanced design. On one occasion walking was at a grade which elicited 32.1 (0.8)% of VO2max, i.e. low intensity, while on the other it elicited 60.1 (1.6)% of VO2max, i.e. moderate intensity (MI). Serum concentrations of total cholesterol (TC), triacylglycerol (TAG), high density lipoprotein cholesterol (HDL-C) and the subfraction HDL2-C free fatty acids (FFA) and free glycerol were measured in venous blood samples drawn before exercise (after a 12-h fast), during walking and after 1 h and 24 h of recovery. Serum TAG concentrations decreased as a result of the exercise bout over the period of observation (P < 0.05), but this decrease was not different between the two intensities. Changes in serum TC concentrations over time differed between trials (P < 0.05). Serum free glycerol and FFA concentrations increased during exercise bouts, these increases being (P < 0.05) greater with MI. The decrease in serum TAG concentrations during and after a single episode of either prolonged low or moderate intensity exercise may be associated with an increased clearance and/or a decreased secretion of TAG-rich lipoproteins.
authors.affiliation: Department of Physical Education, Loughborough University of Technology, Leicestershire, England.
authors.forename: N V
authors.initials: NV
authors.lastname: Tsetsonis
authors.forename: A E
authors.initials: AE
authors.lastname: Hardman
mesh_terms: D000328:Adult; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008055:Lipids / Q000097:blood*; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D013997:Time Factors; D014280:Triglycerides / Q000097:blood; D016138:Walking
chemical_list: D008076:Cholesterol, HDL; D005230:Fatty Acids, Nonesterified; D008055:Lipids; D008074:Lipoproteins; D014280:Triglycerides; D002784:Cholesterol