Effects of an Acute Bout of Continuous versus Accumulated Exercise of Isocaloric Energy Expenditure on Blood Lipids, Lipoproteins and Related Enzyme Activities

Effects of acute bouts of continuous versus accumulated exercise of isocaloric energy expenditure on blood lipids, lipoproteins and related enzyme activities. Purpose: The purpose of this study was to determine if exercise, whether continuous (CE: completed all in one session) or intermittent (completed in either two (IE 2) or three (IE 3) exercise sessions) expending the same number of calories produced similar changes in the lipid/lipoprotein profile as well as transport enzymes. Methods: Sixteen healthy (22±2.1 year old) men (VO2 max = 37.0±3.3 mL∙kg∙min-1) randomly completed three exercise trials, CE, IE 2 and IE 3, expending 450 calories. Baseline data were collected in the evening and included anthropometric measurements, diet records and venous blood samples. The CE trial was done during one continuous time period and the intermittent trials were separated by 4-5 hrs all over the course of one day between the hours of 7 am and 9 pm. In addition to baseline blood samples were drawn immediately post exercise (IPE) and 24 and 48 hours following exercise. Each exercise trial sample was analyzed for total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C) and subfractions (HDL-C2, HDL-C3). Samples were also analyzed to determine LDL-C particle size, lecithin cholesterol acyl transferase activity (LCATa) and cholesterol ester transfer protein activity (CETPa). Results: While no significant alterations in HDL-C and LDL-C were observed HDL-C2 was shown to increase compared to baseline by 44% for CE 48 hours post exercise, 44% for IE 2 48 hours post exercise, 39% for IE 3 IPE and continued to rise for IE 3 48 hours post exercise by 66%. Furthermore, LCATa was significantly increased compared to baseline by 12% for CE 48 hours post exercise and 12% IE 3 48 hours post exercise. Furthermore, there was a 10% increase when comparing CE IPE to CE 48 hours post exercise, a 3% increase between IE 2 24 hours post exercise and IE 2 48 hours post exercise, a 2% increase between IE 3 IPE and IE 3 24 hours post exercise and an 11% increase when comparing IE 3 24 hours post exercise and IE 3 48 hours post exercise. No other significant differences were found. Conclusions: The results of this study indicate that whether the exercise is continuous or intermittent, keeping calorie expenditure the same, causes significant changes in the HDL-C2 subfraction, which was augmented by an increase in LCATa.