Acute Exercise and Training Alter Blood Lipid and Lipoprotein Profiles Differently in Overweight and Obese Men and Women
Author Interview: Nicholas P. Greene, Ph.D.
Cardiovascular Research Center
University of Virginia
What are the main findings of your study?
The purpose of our study was to investigate the therapeutic benefits of single bout exercise and exercise training on measures of blood lipids and lipoproteins in overweight and obese men and women. Although others have reported beneficial changes in blood lipids in response to a single session of exercise (Crouse et al., Journal of Applied Physiology, 1997), we observed only minimal influence of a single bout of exercise on these measures in either men or women. However, when we examined the data following 12 weeks of exercise training we saw, as reported in other populations, an increase in HDL-cholesterol in overweight and obese men.
Also corresponding to previous reports we observed no significant effects of exercise training on total HDL-cholesterol in women. However, the intriguing part of these findings was that while no change in total HDL-cholesterol was observed in women, they did show a change in HDL subfractions which favored enhanced reverse cholesterol transport and thereby a more athero-protective HDL profile.
We have previously shown the efficacy of a novel form of exercise, the aquatic treadmill, to improve aerobic fitness and body composition in this population (Greene et al., Medicine & Science in Sports & Exercise, 2010).
Therefore, we also had subjects perform training using either a conventional land treadmill or the aquatic-based treadmill and observed that these beneficial changes in cholesterol occurred equally regardless of the mode of exercise training. Finally, we saw these beneficial effects despite only minimal weight loss in our population, providing further evidence that exercise can provide therapeutic benefits without the need for dramatic weight loss.
Were any of the findings unexpected?
While many of our findings were expected, we did not necessarily expect to see the shift in HDL subfractions which occurred in our sample of women. These data represent a novel means by which cardiovascular risk may be reduced by exercise in women and support the need for a more detailed analysis of blood cholesterols to evaluate the efficacy of any therapeutic intervention designed to improve such health parameters.
What should clinicians and patients take away from this study?
Exercise training can positively impact health outcomes, particularly blood cholesterols, without the need for dramatic weight loss in overweight and obese adults, and that these effects are seen with multiple modalities of aerobic exercise. Additionally, basic cholesterol panels may not be enough to understand the full efficacy of a therapeutic regimen and should be expanded to include cholesterol subfractions to fully elucidate the efficacy of such regimens.
What recommendations do you have for future research as a result of your study?
Future research should be conducted to see under what conditions a single bout of exercise may alter blood cholesterols in overweight and obese men and women, as the single bouts used in our study appear to have been insufficient.
Also, research should be conducted to better understand the mechanisms by which the gender differences seen in our study occur.
Citation:
Acute Exercise and Training Alter Blood Lipid and Lipoprotein Profiles Differently in Overweight and Obese Men and Women
Nicholas P. Greene, Steven E. Martin and Stephen F. Crouse
Obesity (16 March 2012) | doi:10.1038/oby.2012.65