Is acute supramaximal exercise capable of modulating lipoprotein profile in healthy men?

The Impact of Aerobic Exercise on HDL Quantity and Quality: A Narrative Review

High-density lipoproteins comprise roughly 25-30% of the circulating proteins involved in the transport of lipids in circulation. These particles differ in size and lipid composition. Recent evidence suggests that the quality of HDL particles (which depends on shape, size and the composition of proteins and lipids determining HDL functionality) may be more important than their quantity. The functionality of HDL is mirrored by its cholesterol efflux activity, as well as its antioxidant (including the protection of LDL against oxidation), anti-inflammatory and antithrombotic properties. The results of many studies and meta-analyses imply the beneficial impact of aerobic exercise on HDL-C levels. Physical activity was found to be usually associated with an increase in HDL cholesterol and a decrease in LDL cholesterol and triglycerides. Exercise, apart from inducing quantitative alterations in serum lipids, exerts a beneficial impact on HDL particle maturation, composition and functionality. The Physical Activity Guidelines Advisory Committee Report underlined the importance of establishing a program recommending exercises that enable attainment of maximal advantage at the lowest level of risk. The aim of this manuscript is to review the impact of different types of aerobic exercise (various intensities and durations) on the level and quality of HDL.

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 (D_n is day number), after which blood samples were collected. In ED, compared to D₀, triglycerides (TG) decreased on D_6-10 (p < .01) while total low-density lipoprotein (LDL), total cholesterol (TC) increased on D_2-10, while HDL progressively increased on D_6-10 (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 D_8-10 (p = .01). Moreover, the proportions of TC/HDL and LDL/HDL increased in ED on D_2-10 and D_2-8 (p = .05), respectively, while LDL/HDL in CON was reduced on D_8-10 (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.

High-CHO diet increases post-exercise oxygen consumption after a supramaximal exercise bout

We investigated if carbohydrate (CHO) availability could affect the excess post-exercise oxygen consumption (EPOC) after a single supramaximal exercise bout. Five physically active men cycled at 115% of peak oxygen uptake (V̇O2 peak) until exhaustion with low or high pre-exercise CHO availability. The endogenous CHO stores were manipulated by performing a glycogen-depletion exercise protocol 48 h before the trial, followed by 48 h consuming either a low- (10% CHO) or a high-CHO (80% CHO) diet regime. Compared to the low-CHO diet, the high-CHO diet increased time to exhaustion (3.0±0.6 min vs 4.4±0.6, respectively, P=0.01) and the total O2 consumption during the exercise (6.9±0.9 L and 11.3±2.1, respectively, P=0.01). This was accompanied by a higher EPOC magnitude (4.6±1.8 L vs 6.2±2.8, respectively, P=0.03) and a greater total O2 consumption throughout the session (exercise+recovery: 11.5±2.5 L vs 17.5±4.2, respectively, P=0.01). These results suggest that a single bout of supramaximal exercise performed with high CHO availability increases both exercise and post-exercise energy expenditure.

High and Low Impact Aerobic Exercise as a Method of Early Prevention of Hypercholesterolaemia Development among Young Women

Purpose. Hypercholesterolaemia is a highly prevalent condition that has major health- and cost-related implications for the society. Aerobic-type exercise improves lipoprotein-lipid profiles, cardiorespiratory fitness and body composition in healthy young women. Thus, the aim of the study was to assess the impact of 9 weeks of low-high aerobic-type exercise on the lipid profile among young women. Methods. On the basis of the lipid profile, 64 women (median age, 21.8 years; range, 19.0-24.7 years) were divided into two groups: with low (LRH) and intermediate (IRH) risk of developing hypercholesterolaemia. The participants completed a 9-week-long low-high aerobic exercise programme. Before and after the training programme, we determined the lipid profile: triglycerides (TG), total cholesterol (TC), lipoprotein cholesterol: HDL-C and LDL-C, and glucose levels. Selected cardiorespiratory fitness variables and body composition were also determined. Results. It was found that aerobic-type fitness exercise in the IRH group caused statistically significant decreases in TC and TG levels in comparison with baseline values. Significant increase in maximum oxygen uptake and decrease in HDL-C in the LRH group were also observed. Conclusions. Aerobic fitness exercises, a combination of two alternating styles, could influence the blood lipid profile by decreasing plasma TC and TG levels. In non-athlete women, physical activity may be a good tool to prevent cardiovascular diseases.

Exercise intensity modulation of hepatic lipid metabolism

Lipid metabolism in the liver is complex and involves the synthesis and secretion of very low density lipoproteins (VLDL), ketone bodies, and high rates of fatty acid oxidation, synthesis, and esterification. Exercise training induces several changes in lipid metabolism in the liver and affects VLDL secretion and fatty acid oxidation. These alterations are even more conspicuous in disease, as in obesity, and cancer cachexia. Our understanding of the mechanisms leading to metabolic adaptations in the liver as induced by exercise training has advanced considerably in the recent years, but much remains to be addressed. More recently, the adoption of high intensity exercise training has been put forward as a means of modulating hepatic metabolism. The purpose of the present paper is to summarise and discuss the merit of such new knowledge.