HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 295/4/E851    most recent 90545.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Tsekouras, Y. E. Articles by Sidossis, L. S. Search for Related Content PubMed PubMed Citation Articles by Tsekouras, Y. E. Articles by Sidossis, L. S.

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

Department of Nutrition and Dietetics, Harokopio University, Athens, Greece

Submitted 27 June 2008 ; accepted in final form 24 July 2008

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.

isotope; triacylglycerol; endurance; physical activity; chronic exercise