TY - JOUR

T1 - High-intensity interval aerobic training reduces hepatic very low-density lipoprotein-triglyceride secretion rate in men

AU - Tsekouras, Yiannis E

AU - Magkos, Faidon

AU - Kellas, Yiannis

AU - Basioukas, Konstantinos N

AU - Kavouras, Stavros A

AU - Sidossis, Labros S

N1 - (Ekstern)

PY - 2008

Y1 - 2008

N2 - A single bout of strenuous endurance exercise reduces fasting plasma triglyceride (TG) concentrations the next day (12-24 h later) by augmenting the efficiency of very low-density lipoprotein (VLDL)-TG removal from the circulation. Although much of the hypotriglyceridemia associated with training is attributed to the last bout of exercise, the relevant changes in VLDL-TG metabolism have never been investigated. We therefore examined basal VLDL-TG kinetics in a group of sedentary young men (n = 7) who underwent 2 mo of supervised high-intensity interval training (3 sessions/wk; running at 60 and 90% of peak oxygen consumption in 4-min intervals for a total of 32 min; gross energy expenditure: 446+/-29 kcal) and a nonexercising control group (n = 8). Each subject completed two stable isotope-labeled tracer infusion studies in the postabsorptive state, once before and again after the intervention (approximately 48 h after the last exercise bout in the training group). Peak oxygen consumption increased by approximately 18% after training (P ≤ 0.05), whereas body weight and body composition were not altered. Fasting plasma VLDL-TG concentration was reduced after training by approximately 28% (P ≤ 0.05), and this was due to reduced hepatic VLDL-TG secretion rate (by approximately 35%, P ≤ 0.05) with no changes (<5%, P > 0.7) in VLDL-TG plasma clearance rate and the mean residence time of VLDL-TG in the circulation. No significant changes in VLDL-TG concentration and kinetics were observed in the nonexercising control group (all P ≤ 0.3). We conclude that a short period of high-intensity interval aerobic training lowers the rate of VLDL-TG secretion by the liver in previously sedentary men. This is different from the mechanism underlying the hypotriglyceridemia of acute exercise; however, it remains to be established whether our finding reflects an effect of the longer time lapse from the last exercise bout, an effect specific to the type of exercise performed, or an effect of aerobic training itself.

AB - A single bout of strenuous endurance exercise reduces fasting plasma triglyceride (TG) concentrations the next day (12-24 h later) by augmenting the efficiency of very low-density lipoprotein (VLDL)-TG removal from the circulation. Although much of the hypotriglyceridemia associated with training is attributed to the last bout of exercise, the relevant changes in VLDL-TG metabolism have never been investigated. We therefore examined basal VLDL-TG kinetics in a group of sedentary young men (n = 7) who underwent 2 mo of supervised high-intensity interval training (3 sessions/wk; running at 60 and 90% of peak oxygen consumption in 4-min intervals for a total of 32 min; gross energy expenditure: 446+/-29 kcal) and a nonexercising control group (n = 8). Each subject completed two stable isotope-labeled tracer infusion studies in the postabsorptive state, once before and again after the intervention (approximately 48 h after the last exercise bout in the training group). Peak oxygen consumption increased by approximately 18% after training (P ≤ 0.05), whereas body weight and body composition were not altered. Fasting plasma VLDL-TG concentration was reduced after training by approximately 28% (P ≤ 0.05), and this was due to reduced hepatic VLDL-TG secretion rate (by approximately 35%, P ≤ 0.05) with no changes (<5%, P > 0.7) in VLDL-TG plasma clearance rate and the mean residence time of VLDL-TG in the circulation. No significant changes in VLDL-TG concentration and kinetics were observed in the nonexercising control group (all P ≤ 0.3). We conclude that a short period of high-intensity interval aerobic training lowers the rate of VLDL-TG secretion by the liver in previously sedentary men. This is different from the mechanism underlying the hypotriglyceridemia of acute exercise; however, it remains to be established whether our finding reflects an effect of the longer time lapse from the last exercise bout, an effect specific to the type of exercise performed, or an effect of aerobic training itself.

KW - Adult

KW - Aerobiosis/physiology

KW - Anaerobic Threshold/physiology

KW - Anthropometry

KW - Body Composition/physiology

KW - Calorimetry, Indirect

KW - Diet

KW - Humans

KW - Kinetics

KW - Lipids/blood

KW - Lipoproteins, VLDL/metabolism

KW - Liver/metabolism

KW - Male

KW - Metabolism/physiology

KW - Oxidation-Reduction

KW - Physical Fitness/physiology

KW - Triglycerides/metabolism

U2 - 10.1152/ajpendo.90545.2008

DO - 10.1152/ajpendo.90545.2008

M3 - Journal article

C2 - 18664593

VL - 295

SP - E851-E858

JO - American Journal of Physiology - Endocrinology and Metabolism

JF - American Journal of Physiology - Endocrinology and Metabolism

SN - 0193-1849

IS - 4

ER -