Idle Awhile? Exercise May Reverse Harm

June 2, 2006 -- Been sitting on the sidelines from exercise for awhile? Think you're past the point of no return? Think again.

New research shows that middle-aged, overweight adults who have been sedentary for six months can overcome the negative health effects of inactivity with just six months of exercise.

"Many of the detrimental effects of physical inactivity can be reversed with a similar period of exercise training," write Duke University exercise physiologist Jennifer Robbins and colleagues.

What's more, people with the steepest health setbacks from inactivity seem to reap the biggest benefits from getting back to exercise, Robbins' team reports.

Robbins presented the findings at the American College of Sports Medicine's 53rd annual meeting in Denver, this week.

Sedentary for 6 Months

In the study, Robbins and colleagues looked at 53 middle-aged, overweight people who had been sedentary for six months.

Before and after the six-month period, researchers checked participants for 17 traits, including:

• Body mass
• Minimal waist size
• Fat that is deep inside the abdomen (visceral fat)
• LDL ("bad") cholesterol
• Time to exhaustion (how long it takes to become exhausted by exercise)
• Sensitivity to insulin, a hormone that controls blood sugar

As you might guess, six months of physical inactivity weren't good for those traits.

During the sedentary period, participants' waists expanded. They added more visceral fat, became exhausted by exercise quicker, and showed more signs of the metabolic syndrome, a cluster of risk factors that makes heart disease and diabetes more likely.

Getting Back in the Game

After six months of sedentary life, participants started exercising in one of three programs designed by the researchers.

Thirty-three participants stuck with their exercise program for six months. At the end of that time, they showed improvement in 13 of the 17 traits measured. Their readings for those traits either returned to where they had been before the sedentary period or became even better.

"In addition, we observed that individuals who experienced the greatest decline while inactive appeared to obtain the largest improvements during the exercise regimen that followed," wrote Robbins and her colleagues, who included other experts from Duke and from East Carolina University in Greenville, N.C.

Grueling Workouts Not Required

Participants didn't have to crank their workouts to extremes to reap the benefits.

"When looking at the group as a whole, we found that it wasn't the participants with the highest intensity of exercise who accounted for the combined beneficial effects," Robbins said, in a Duke news release.

"That should be reassuring for people to know they don't have to do a high-intensity workout to get these benefits of exercise," Robbins added.

Keep in mind that participants didn't just decide to hit the gym after a long idle period without getting medical clearance.

Anyone who's been inactive -- especially for health reasons -- should get a doctor's OK before starting a new workout program. Newcomers and long-time exercisers alike should also take care not to push themselves too hard, too soon.

Robbins' study showed that better fitness is within reach for people who decide to stop being sedentary. The keys are patience, consistency -- and making the decision to get started (with appropriate medical help, of course).

SOURCES: American College of Sports Medicine's 53rd Annual Meeting, Denver, May 31-June 3, 2006. News release, Duke University School of Medicine.