The finding could be a boon to older adults, since age tends to slow down wound healing, raising infection risk, write Charles Emery, PhD, and colleagues.
The results recently appeared in the Journal of Gerontology: Medical Sciences. Here's how the study worked.
Step 1: Get Moving -- or Not
Emery's study included 28 older adults who were 55-75 years old. At the study's start, all participants were sedentary, meaning they hadn't exercised regularly for at least six months.
Half were told to work out three times per week at Ohio State. Here's what each session involved:
- Warm up for 10 minutes with stretches.
- Ride a stationary bike for 30 minutes hard enough to maintain a certain goal heart rate.
- Walk briskly and/or jog for 15 minutes.
- Use exercise equipment to strengthen arm muscles.
- Cool down for five minutes.
The other participants were told to stay sedentary. Both groups were asked not to change their normal diets.
Step 2: Get Wounded
After a month, the researchers gave participants tiny skin wounds in the back of their upper arms. Right-handed participants got the wound in their left arm and vice versa.
The month's delay allowed the exercisers' bodies to adjust to their new routine.
The wounds were immediately bandaged for 24 hours. After that, no bandage was needed.
A week later, the researchers photographed each wound with a high-resolution digital camera. The wounds were photographed three days per week until they had healed and couldn't be seen.
The goal was to see which group healed more quickly. The researchers predicted that the exercisers would win that race.