Continuous and intermittent walking alters HDL2-C and LCATa

PurposeThe 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 alters reverse cholesterol transport or low density lipoprotein (LDL) particle size.MethodsSixteen healthy (22 ± 2.1 year old) men (VO2 max = 37.0 ± 3.3 mL/kg/min) randomly completed three exercise trials, CE, IE 2 and IE 3, expending 450 calories. Blood samples were drawn immediately post-exercise (IPE) and 24 and 48 h following exercise and analyzed for total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C) and subfractions (HDL2-C, HDL3-C). Samples were also analyzed to determine LDL-C particle size, lecithin cholesterol acyl transferase activity (LCATa) and cholesterol ester transfer protein activity (CETPa).ResultsHDL2-C increased significantly 48 h post-exercise in the CE and IE 2 groups. Additionally, the IE 3 group had significant increases in HDL2-C at 24 (39%) and 48 h post-exercise by 66%. This change in HDL2-C was significantly and positively correlated (r = 0.62; p < 0.05) to the changes in LCATa which increased compared to baseline at 48 h post-exercise in the CE and IE 3 groups. No significant changes in LDL particle size or alterations in CETPa were seen.ConclusionsThe results of this study indicate that whether the exercise is continuous or intermittent, keeping calorie expenditure the same, causes significant changes in the HDL2-C subfraction, which was augmented by an increase in LCATa.