Exercise may increase ‘good cholesterol’

WASHINGTON: A new study has found that regular exercise might modestly increase levels of high-density lipoprotein (HDL), or ‘good cholesterol’.

HDL can remove cholesterol from atheroma within arteries and transport it back to the liver for excretion or re-utilisation, which is the main reason why HDL-bound cholesterol is sometimes called good cholesterol.

A low level of high-density lipoprotein cholesterol (HDL-C) is an independent risk factor for cardiovascular disease, the leading cause of death worldwide.

The study was conducted by a team of researchers led by Satoru Kodama at Ochanomizu University, Tokyo.

As part of the study, researchers performed a meta-analysis of 25 articles reporting the results of randomised controlled trials that were published between 1966 and 2005.

The study included a total of 1,404 participants with an average age range of 23 to 75 years and an average study period of 27.4 weeks to assess the effects of exercise on HDL-C.

The exercise groups were told to exercise for an average of 3.7 sessions per week at an average of 40.5 minutes each, burning an average of 1,019 calories per week.

To be included in the analysis, the studies had to evaluate aerobic exercise in adults with an average age of 20 or older, specify HDL-C measurements at the beginning and end of the study, have a length of at least eight weeks, and randomly assign some participants to a group of exercisers and others to a control group of non-exercisers.

Researchers found that in all the studies combined, HDL-C increased by an average of 2.53 milligrams per decilitre in the exercise groups.

The minimum amount of weekly exercise that appeared necessary to change HDL-C levels was 120 minutes or 900 calories burned.

The effect of exercise was greater in those who had a higher total cholesterol level and in those with a body mass index of less than 28.

Only exercise duration, and not frequency or intensity, was associated with a change in HDL-C levels in the analysis.

When the participants exercised for 23 to 74 minutes per session, each 10-minute increase in exercise duration corresponded to a 1.4-milligram per decilitre increase in HDL-C level.

"This suggests that in improving blood HDL-C values, increasing time per session is better than performing multiple brief exercise sessions when total time for exercise is limited, as is the case for many people," the authors wrote.

The findings of the study were published in the May issue of Archives of Internal Medicine , one of the JAMA/Archives journals.

(The above article has been taken from IndiaTimes.com)