Want to reverse the affects aging has on your skin? Forget creams, lotion or skin peels, Canadian researchers say -- think about jogging around your local park instead.

A study at McMaster University suggests exercise can reverse those effects on a microscopic level, even among people who start exercising regularly later in life.

"[What] it shows is that exercise is something we should be doing not just for our hearts and our brains and to lower cancer risk," says Dr. Mark Tarnopolsky, McMaster professor of exercise science and pediatrics, "but also it's going to make our skin healthier."

The researchers, in a presentation of findings at The American Medical Society for Sports Medicine this month, described their study involving 29 female and male volunteer participants, whose ages ranged from 84 down to 20.

Around half the volunteers engaged in a minimum of three hours of vigorous or moderate exercise weekly while the rest followed a mostly sedentary regime, with less than one hour of activity a week.

Taking skin samples from participants' buttocks -- chosen because skin there rarely gets exposed to sunlight -- they found those of the active volunteers over age 40 displayed skin that was demonstrably younger-looking.

The samples resembled those of people in their 20s to 30s, even in study participants aged 65 and older, the researchers said.

Normally with age a skin layer called the stratum corneum, the protective, outermost layer of our skin, becomes thicker and, made up predominantly of dead skin cells, dries out to become flaky and saggy.

In study participants over the age of 40 who exercised regularly, the researchers found stratum corneums that were healthier and thinner.

"I don't want to over-hype the results, but, really, it was pretty remarkable to see," says Tarnopolsky. In microscopic examination the older volunteers' skin "looked like that of a much younger person, and all that they had done differently was exercise."

As part of their study, the scientists looked at substances called myokines, created by muscles that are exercised, which can enter a person's bloodstream and initiate change in cells in other parts of the body.

Levels of one particular myokine known as IL-15 were greatly elevated in those in the study who were exercising regularly, they said.

"It is astonishing to consider all of the intricate ways in which exercise changes our bodies," Tarnopolsky says.