Fitness

Effect of Intensity of Exercise on Blood Lipids

The intensity of the exercise appeared to be less
important than the amount
of exercise in terms of
blood lipid improvements.

Duke University studied this question by putting people on three different exercise regimes to see which would be the most effective.
1. Moderate intensity, equivalent of walking 12 miles per week
2. High intensity, equivalent of running 12 miles per week
3. High intensity, equivalent to running 20 miles per week

Each group exercised for 8 months. Weight was held constant to eliminate weight loss as a factor in lipid changes.

In those exercising at the 12 miles per week level, both the walkers and runners saw improvement in blood lipids (lower triglyceride levels and other positive changes in LDL cholesterol). The improvements were related more to the amount of activity, however, than to the intensity.

Joggers who competed 20 aerobic miles weekly at a moderate pace had the most improvement, especially in HDL cholesterol levels. After 8 months of training, their HDL levels rose about 10%. Other research shows that for every 1% your HDL levels increase, your risk of heart disease drops by 2-3%. That would be a drop in coronary risk of 20-30%.

Those who exercised at the 12 miles per week level had many improvements, but neither group had a significant increase in HDL cholesterol. It appears that you need more exercise to see improvements in HDL, at least 15-20 aerobic miles per week for significant improvement. Those who got the most exercise had the greatest improvement overall in lipid changes important to heart health.

These findings are consistent with the recommendations from the Institute of Medicine (IOM). The IOM increased the recommended amount of moderate exercise from 30 to 60 minutes daily when possible. An hour's walk 4-5 times per week would be equivalent to 16-20 miles per week. Jogging for 30-35 minutes, 5 times per week would be equivalent to 15 to 20 aerobic miles per week. While any exercise is beneficial, it appears that 15-20 aerobic miles per week may be optimum for best health.

This study is also good news for those who find it easier to exercise daily than to lose weight. Activity can improve blood lipid results even without weight loss.

Reference

Kraus WE, et al. Effects of the amount and intensity of exercise on plasma lipoproteins, New England Journal of Medicine Nov 7, 2002; 347:1483-92

Making Healthy Choices articles are written by Don Hall, DrPH, CHES president of LifeLong Health with contributions from associated health professionals. Content is general health information from evidence based research. It's purpose is not to treat disease or take the place of advice by your doctor but to promote healthy lifestyles. Persons with health problems should contact their physician for specific guidance.

Copyrighted 2002 by PrevMedix LLC. All rights reserved. Do not make unauthorized copies.

Updated: 12/17/02