Not only does hitting the gym add years to one's life, it may also reverse skin aging, according to a recent study Counsel and Heal reported.

Researchers from McMaster University in Ontario, Canada found that exercise could make people look 20 to 30 years younger.

After people reached 40 years old, the stratum corneum - the protective, outer layer of the skin -- starts to thicken while the inner layer, known as the dermis starts to thin. The thinning process of the dermis indicates "that the skin is losing cells and elasticity, which then leads to saggy skin," Counsel and Heal reported.

For the study, researchers tested the effects of exercise on the skin by collecting data from 29 men and women between the ages of 20 and 84. They took skin biopsies of the study participants' buttock where sun damage would not be a factor. The samples showed that older individuals had thicker outer layers and thinner inner layers in comparison to younger people.

Roughly 50 percent of the participants were physically active and exercised at least three hours per week. When physical activity in participants older than 40 were accounted for, researchers discovered that the skin of people who exercised frequently did not age as fast in comparison to the skin of sedentary people of similar age, Counsel and Heal reported.

Older adults who were more active adults had thinner and healthier stratum corneums and thicker dermis layers -- their skin samples were much closer to people in their 20s and 30s in terms of composition.

During the study, researchers also instructed sedentary participants who were 65 and older. They were started on an endurance training program that involved working out two times a week. Researchers collected skin biopsies from them at the end of the training and found that the skin showed signs of reverse aging.

According to Counsel and Heal, researchers are not sure how exercise helps reverse skin aging. However, the evidence suggests that people who want to look younger should start exercising.

"I don't want to over-hype the results, but, really, it was pretty remarkable to see," Dr. Mark Tarnopolsky, a professor of pediatrics and exercise science at McMaster who oversaw the study, said according to the New York Times.

The findings were presented at the American Medical Society for Sports Medicine annual meeting in New Orleans, La.