Weight loss with cardio requires four sessions a week

Weight loss is often most successful if you eat a little less but really increase the amount of exercise you get. It’s better to burn calories than not eat them. To do this you need to do at least four half-hour cardio sessions per week, American researchers write in the Journal of Strength and Conditioning Research.

The researchers did a trial with 80 fat men and women aged between 22 and 74. The men had a fat percentage of 25 or more, the women had a fat percentage of 35 or more. Some participants had a body fat percentage that was high enough to be a health risk. The test subjects were all healthy, but had a sedentary lifestyle.

The test subjects were not put on a diet. A control group of 20 fatties did no exercise at all, 20 fatties trained once a week for eight weeks, another 20 fatties trained 2-3 times a week, and another 20 trained 4 times a week or more. A training session consisted of 30 minutes continuous cardio exercise at 70 percent of the person’s maximal heart rate.

After 8 weeks the researchers measured the test subjects’ fat mass again.


The subjects in the control group had gained just under a kilogram of fat. The subjects who trained 1-3 times a week lost 2 kilograms of fat; the subjects that had trained 4 times a week or more lost 6 kilograms of fat. Only the fat loss of the latter group was statistically significant.

Frequency of exercise for body fat loss: a controlled, cohort study.


The purpose of this study is to examine the changes in body fat mass of previously sedentary, deconditioned subjects who began following the U.S. Surgeon General’s recommendation in frequency of exercise. Ninety subjects of both sexes were recruited; ages ranged from 22 to 74 (mean 37.5 +/- 13) years. Subjects were prescribed exercise of 4 times a week, 30 minutes of continuous exercise, for 8 weeks. Eighty subjects completed the 8-week study and were categorized based on voluntary compliance: control (no exercise); exercise less than 2 times/week; exercise 3 to 4 times/week; exercise 4 or more times/week. Body fat mass was the dependent variable in this study, as measured by air displacement plethysmography, and data analysis was accomplished with a repeated measures analysis of variance. There was a significant change in body fat mass in this study, but the only significant difference between groups was for the group that exercised 4 or more times/week, (p = 0.004). Adherence to the U.S. Surgeon General’s Guidelines for frequency of exercising 4 times per week for 30 minutes was effective in reducing subjects’ body fat mass in this study.

PMID: 19826285 [PubMed – indexed for MEDLINE]

Source: http://www.ncbi.nlm.nih.gov/pubmed/19826285