Perhaps more of us would get off the couch and onto the treadmill if we were faced with images of the difference exercising may make in our appearance in 20 years.

Some study participants now have such pictures to motivate them: Researchers from the University of St. Andrews in Scotland released images of three people this week, projecting how they'll look in 20 years if they exercise, and how they'll look if they don't.

The imaging technology, which has been developed over the last 15 years, used mathematical models to predict how the shape, color and texture of the face change in those who don't exercise regularly, researcher Ross Whitehead said. [Images: Photos of the technologically aged study participants]

The researchers defined regular exercise as 30 minutes of moderate activity, five times a week.

"Weight gain is the main impact of no exercise, rather intuitively, but we also took into account various factors that affect skin quality," Whitehead told MyHealthNewsDaily. "This technique can be applied to any factor that affects facial appearance, (and) we looked at the impact of exercise."

The aim of the study was to show how an active lifestyle can improve appearance as well as health, Whitehead said. The process took into account the average annual weight gain that occurs with aging – about 1 ¼ pounds (0.5 kilograms) for women and 1 ½ pounds (0.7 kg) for men. Images of the participants' faces were also created assuming the participants exercised regularly.

The images show that sagging, loose skin on the neck and jowls are the most pronounced effect of not exercising, Whitehead said. The forehead and eye area also tend to fatten more in inactive people.

The researchers are now doing intervention studies to try to motivate people to change their behavior by demonstrating the effects of several lifestyle choices, Whitehead said.

"This is merely the tip of the iceberg for the research," he said. "We plan eventually to incorporate a range of factors associated with healthy living — diet, exercise, tobacco and alcohol use — and illustrate to people the impact of their daily habits on their appearance."

The three volunteers in the study were recruited as part of Active Nation, an initiative encouraging people in Scotland to exercise more during the build-up to the 2014 Commonwealth Games in Glasglow.

"The participants seeing these images were relatively shocked by them," Whitehead said, "and all resolved to improve their exercise regimen."

One of the volunteers, Catherine Duffy, 43, stays active playing hockey, and said she is surprised when she notices others avoiding exercise at all costs.

"I think if everyone got to see what they would look like in 20 years, they would be straight down to the gym without giving it a second thought," Duffy said.