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: 106/4/1079    most recent 91262.2008v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bajpeyi, S. Articles by Houmard, J. A. Search for Related Content PubMed PubMed Citation Articles by Bajpeyi, S. Articles by Houmard, J. A.

Effect of exercise intensity and volume on persistence of insulin sensitivity during training cessation

¹Department of Exercise and Sports Science, ²Human Performance Laboratory, and ³Diabetes/Obesity Center, East Carolina University, Greenville; and ⁴Division of Cardiovascular Medicine, Department of Medicine and ⁵Duke Center for Living, Duke University Medical Center, Durham, North Carolina

Submitted 22 September 2008 ; accepted in final form 29 January 2009

The purpose of this study was to determine whether exercise prescriptions differing in volume or intensity also differ in their ability to retain insulin sensitivity during an ensuing period of training cessation. Sedentary, overweight/obese subjects were assigned to one of three 8-mo exercise programs: 1) low volume/moderate intensity [equivalent of 12 miles/wk, 1,200 kcal/wk at 40–55% peak O₂ consumption (O_2peak), 200 min exercise/wk], 2) low volume/vigorous intensity (12 miles/wk, 1,200 kcal/wk at 65–80% O_2peak, 125 min/wk), and 3) high volume/vigorous intensity (20 miles/wk, 2,000 kcal/wk at 65–80% O_2peak, 200 min/wk). Insulin sensitivity (intravenous glucose tolerance test, S_I) was measured when subjects were sedentary and at 16–24 h and 15 days after the final training bout. S_I increased with training compared with the sedentary condition (P 0.05) at 16–24 h with all of the exercise prescriptions. S_I decreased to sedentary, pretraining values after 15 days of training cessation in the low-volume/vigorous-intensity group. In contrast, at 15 days S_I was significantly elevated compared with sedentary (P 0.05) in the prescriptions utilizing 200 min/wk (low volume/moderate intensity, high volume/vigorous intensity). In the high-volume/vigorous-intensity group, indexes of muscle mitochondrial density followed a pattern paralleling insulin action by being elevated at 15 days compared with pretraining; this trend was not evident in the low-volume/moderate-intensity group. These findings suggest that in overweight/obese subjects a relatively chronic persistence of enhanced insulin action may be obtained with endurance-oriented exercise training; this persistence, however, is dependent on the characteristics of the exercise training performed.

obesity; physical activity; cardiovascular disease; metabolic syndrome

This article has been cited by other articles:

				C. A. Slentz, C. J. Tanner, L. A. Bateman, M. T. Durheim, K. M. Huffman, J. A. Houmard, and W. E. Kraus Effects of Exercise Training Intensity on Pancreatic {beta}-Cell Function Diabetes Care, October 1, 2009; 32(10): 1807 - 1811. [Abstract] [Full Text] [PDF]