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.
PY - 2008/10
Y1 - 2008/10
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 (∼48 h after the last exercise bout in the training group). Peak oxygen consumption increased by ∼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 ∼28% (P ≤ 0.05), and this was due to reduced hepatic VLDL-TG secretion rate (by ∼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 (∼48 h after the last exercise bout in the training group). Peak oxygen consumption increased by ∼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 ∼28% (P ≤ 0.05), and this was due to reduced hepatic VLDL-TG secretion rate (by ∼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 - Chronic exercise
KW - Endurance
KW - Isotope
KW - Physical activity
KW - Triacylglycerol
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U2 - 10.1152/ajpendo.90545.2008
DO - 10.1152/ajpendo.90545.2008
M3 - Article
C2 - 18664593
AN - SCOPUS:56049095500
SN - 0193-1849
VL - 295
SP - E851-E858
JO - American Journal of Physiology - Endocrinology and Metabolism
JF - American Journal of Physiology - Endocrinology and Metabolism
IS - 4
ER -