Sore Back? Exercise, Study Suggests

However, those who hit the gym only two or three days a week did not show the same level of change.

"While it could be assumed that someone with back pain should not be exercising frequently, our findings show that working with weights four days a week provides the greatest amount of pain relief and quality of life," said Robert Kell, lead author of the study and an assistant professor of exercise physiology at the University of Alberta.

About 80 percent of North Americans suffer from lower back pain, Kell and his colleagues say. Others put the figure lower, but some 75 million U.S. residents are said to suffer chronic or recurrent pain of some sort.

Either way, evidence for exercise as the best medicine is stacking up.

Kell presented some of the findings May 30 at the American College of Sports Medicine conference in Seattle.

In the study, groups of 60 men and women with chronically sore lower backs each exercised with weights in two, three or four-day weekly programs, or not at all. Their progress was measured over 16 weeks. The level of pain decreased by 28 per cent in programs that included exercise four days a week, by 18 per cent three days a week and by 14 per cent two days a week. The quality of life, defined as general physical and mental well-being, rose by 28 per cent, 22 per cent and 16 per cent respectively.

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