From the article:
Each subject received a small puncture wound on the back of the upper arm. Adults in the exercise group started working out about a month before the wound procedure; this gave their bodies enough time to adapt to a regular exercise program.
The exercises were a combination of aerobic and strength training:
At the end of the study, the researchers found that skin wounds healed an average of 10 days faster in the people who exercised (29 days in the exercise group vs. 39 days in the non-exercise group.)