At the age of 18, Shaun Stafford was 6 feet tall and weighed 143 pounds—hardly the typical body type for a rugby player. However, he was chosen by the University of Oxford, home to one of the world's leading rugby clubs. He made it on to the team, but his coach said to him, "You've got to gain weight, son, or you're going to be killed."

To his followers on social media (he has more than a million Facebook likes), Stafford jokes that he's made of glass, partly due to a shoulder injury he sustained in his early 20s. His doctor at the time told Stafford that his shoulder would have to be completely reconstructed or he'd have to quit playing rugby.

"I thought about that and realized I'd found something I enjoyed as much as rugby: weight training. So, I started just getting into training for training's sake," says Stafford. "That coincided with the time when physique shows and fitness modeling were just starting out, so my training partner and I decided to enter a show and see what happened."

And a lot did happen for him. Stafford went on to become an international cover model, a Team Optimum Nutrition sponsored athlete, the 2012 WBFF Pro Fitness Model World Champion, and a Bodybuilding.com contributor. Now that Stafford is in his mid-30s and has put in more than his share of gym hours, he's learned to evolve his training to get exactly what he wants out of the gym.

"I want to stay lean and strong, but now I also want to be pain-free. I want to be mobile. I want to be flexible. I have a wife, a new baby, and a dog. I want to be able to pick up my son and play with him. I want to be able to go for a 5K run with my dog," says Stafford. "I want the things that give me a really good quality of life. And that means creating a slightly more balanced and well-rounded sort of training."

Throughout his career, Stafford has focused on providing both motivation and information to others. His Shaun Stafford Fitness business is doing well, and he loves being able to travel around the world interacting with people. But he keeps it all in perspective.

"A lot of people in the fitness industry take themselves really seriously," says Stafford. "And don't get me wrong—half of fitness is serious business. But we're not out there curing cancer. We're not out there fighting wars. All we're trying to do is have a positive impact on people's lives."

For Stafford, that means getting people to lighten up a bit and showing them how you can have a well-balanced life while still being heavily into fitness.

"I want people to know that you can enjoy a meal out and not have to kill yourself on the treadmill to make up for it," he says. "If people can take something away from what I'm saying, it would be to have a well-balanced outlook, stay fit, stay healthy, and have a great life!"