A new study indicates that working out too much may not have any health benefit.

To determine what was an optimal working reimagine, researchers at the University of Alabama at Birmingham organized three different workout groups of 72 elderly and inactive women.

The three groups were split up based on the amounts and days of exercise they would be performing. One group lifted weights once a week and did an aerobic workout once a week. One group did weight training exercises twice a week and active twice a week and the last group did both types of exercise for 3 days a week each.

The workouts started out easy and progressed over four months to more challenging levels so the participants would work their muscles and increase their endurance.

In the study, researchers tracked levels of cytokines, molecules that the body produces when it senses that it is stressed out. They also looked at the change in muscle strength, body fat, moods, aerobic capacity and exactly how much energy they expended in a week.

After four months, there was little difference in the strength gain and endurance of all three groups. But when they looked at the amount of energy the women were expending each week, the group that exercised four times a week burned 225 more calories than the groups that exercised more and less. This middle of the road group was also burning through 100 more calories a day.

"We think that the women in the twice-a-week and four-times-a-week groups felt more energized and physically capable," said Gary Hunter, the lead researcher on the experiment.

Dr. Hunter concluded that "less may be more," and that the women exercising four times a week had the greatest amount of energy being spent. 

The report published in Exercise & Science in Sports & Medicine can be found here.