Ill effects of inactivity reversible with exercise

NEW YORK, June 7 (Reuters) Couch potatoes can lower their risk of developing heart disease, diabetes and other health conditions, if they start spending as much time exercising as they previously spent being inactive, new study findings suggest.

In the study, men and women whose health and fitness deteriorated when they volunteered to be physically inactive for six months, had a complete reversal of most of the subsequent deterioration in health measures when they increased their activity level during the next six months.

''Inactivity is worse than we thought,'' study co-author Jennifer L. Robbins, an exercise physiologist at Duke University in Durham, North Carolina, told Reuters Health. Yet, she said, ''a little bit of activity can make a big difference.'' Robbins presented her team's findings during last week's annual meeting of the American College of Sports Medicine, held in Denver, Colorado.

''Although exercise is known to enhance health and wellness, the extent to which one can reverse the debilitating effects of physical inactivity is unknown,'' Robbins and her associates note in materials provided at the meeting.

To look into that issue, they studied mildly overweight but otherwise healthy individuals who had been assigned to a comparison group of a previous exercise study, in which they were instructed to not make any changes in their diet or exercise level -- i.e. to continue their normal pattern of inactivity -- for a six-month period. These participants afterwards elected to follow the study's exercise program for an additional six months.

During their period of inactivity, the men and women experienced deterioration in 12 of the 17 variables studied, including their waist size, how quickly they became exhausted while using a treadmill, and their visceral fat, or the amount of fat surrounding their internal organs -- a known predictor of cardiovascular disease.

After six months of exercise, however, the 33 study participants decreased their waist size, lost weight, exercised longer before becoming exhausted on a treadmill, lowered their cholesterol and otherwise improved in 13 of the 17 variables studied, according to Robbins and her team.

The exercise returned these variables to ''normal'' -- i.e. to the levels measured before the initial study began -- or even led to improvements beyond those initial levels.

''It's promising to know with a similar period of activity, health parameters can be reversed,'' Robbins said.

What's more, study participants who fared the worst during the sedentary period also experienced the greatest improvement during the exercise program, the researchers note.

This is good news for men and women who recently gained weight, according to Robbins. ''They may indeed be the ones who have the most benefit'' from increasing their level of physical activity, she said.

The study findings indicate that ''it only takes a small amount of activity to make a difference and to keep cardiovascular risk factors at a manageable level,'' Robbins said.

''Something's better than nothing and more is better than less, generally,'' she added.

The research was funded by a grant from the National Institutes of Health.

REUTERS CH RK0928