Jerry Rice talks about exercising outside

Football legend Jerry Rice shows that you can use newspaper boxes to do modified pushups. Courtesy of Gillette

Football legend Jerry Rice, who turned 50 a month ago, is in San Francisco to promote Gillette's My City is My Gym campaign.

"As a former player, fitness is everything to me," said Rice, who was inducted into the Pro Football Hall of Fame in 2010 after 19 years in the NFL. "When I played football, I would work out in the gym, and then I'd love to work out in the outdoors. It gives you life."

Rice, who works for ESPN as a broadcaster, is the third athlete to work on this project. Chicago Blackhawks star Patrick Sharp (Chicago) and former NFL linebacker Dhani Jones (New York) were the other two.

The goal is to show people that you can use everyday objects to get in a good workout.

"A lot of people can't afford to go to a gym because it's so expensive," Rice said. "You can just go to a park to do pushups and you can create your own workout."