The effect of 10 days of energy-deficit diet and high-intensity exercise training on the plasma high-density-lipoprotein (HDL) level among healthy collegiate males.

ABSTRACTAn energy-deficit (ED) diet increases lipid mobilisation, while endurance exercise improves lipid profile by promoting formation of high-density lipoproteins (HDLs) among moderately active population. However, it is not clear whether ED with high-intensity exercise training can improve lipid profiles. Therefore, 20 recreationally active males (20.3 ± 2.7 years old with peak oxygen consumption (V˙O2peak) of 2.8 ± 0.2 L min-1) with HDL concentration of 1.44 ± 0.32 mmol L-1, were evenly allocated to either an ED group (1590 ± 79 kcal day-1: 40% of total caloric omitted at lunchtime) or a control (CON) group (2570 ± 139 kcal day-1). Participants in both groups performed high-intensity cycling at 90% V˙O2peak at a constant workload for 8 min, 2 h after breakfast on day D0, D2, D4, D6, D8 and D10 (Dn is day number), after which blood samples were collected. In ED, compared to D0, triglycerides (TG) decreased on D6-10 (p < .01) while total low-density lipoprotein (LDL), total cholesterol (TC) increased on D2-10, while HDL progressively increased on D6-10 (p = .01) with a final value of 1.67 ± 0.24 mmol L-1. In CON, there were no changes in TG, TC and HDL while LDL was reduced on D8-10 (p = .01). Moreover, the proportions of TC/HDL and LDL/HDL increased in ED on D2-10 and D2-8 (p = .05), respectively, while LDL/HDL in CON was reduced on D8-10 (p = .01). In brief, 10 days of ED and a series of high-intensity exercise sessions show progressive elevation of HDL which suggest longer period is required to observe changes in lipid ratios.