Statins reduce low-density lipoprotein otherwise known as bad cholesterol, and lowers the risk of heart disease and atherosclerosis. Statins have mild adverse effects, and a new study shows that some may even cause men to exercise less.

Oregon State University researchers found that men who were on statins were less prone to work out as they age. Based on the Osteoporotic Fractures in Men Study data, 3,039 men were observed on how much exercise they get with only some of them use statins for seven years. 727 men who frequently used the drug, 845 men who just started using it and 1,467 men who did not use statins at all during the study period.

The men who reported their work out habits wore an activity monitor for one-week period by the end of the research period. It showed a slight decline for all men but those who started to use statin demonstrated faster decline rates of activity compared to men who remained without it. Prevalent users were less likely to work out compared to those who were never on it and the reduction was 2.8 and 2.5 points a year, respectively. Those who started statins during the study period reduced 3.4 points off their work out routines. Overall, those who used statins exercised 5.4 minutes less a day, engaged 0.06 minutes less of vigorous activities and were sedentary for nearly eight minutes more a day.

The researchers did not find out why statins lead to weak muscles and said that chemical processes cause a disruption in the production of adenosine triphosphate (ATP) and this could lead to feelings of weakness because ATP is responsible for storing energy. The findings back up previous studies that linked reduction in activity and statin medication use such as Pravachol, Zocor, Lipitor, Crestor, Vytorin and Lescol. However, the researchers do not encourage people to stop taking their cholesterol-lowering drugs.

"The findings should not change recommendations in people who are in categories that clearly show net benefit for the patient -- [as] gauged by benefit to all-cause mortality -- like middle-aged men with heart disease ... who on average clearly show mortality benefit from statins," Beatrice Golomb, MD, PhD from University of California San Diego said. "But they might actually moderate enthusiasm for prescribing statins in other groups, where, on average, all-cause mortality has been neutral and all-cause serious adverse effects have been neutral." The study involved older men and may not apply to older women.