From sandiego.padres.mlb.com (via joystiq.com):

At first, playing the Nintendo Wii was merely a way for Padres relief pitcher Heath Bell to engage in another fun activity with his three children.

"It started out that way, but then I tried the yoga and the strength training and I found that I was sweating every single time. I figured, ‘Why not do this once in a while?’ So I began playing and my wife and kids thought I was crazy because I was sweating so much."

Bell said Monday that his workouts with the Nintendo Wii Fit were a big reason why he dropped about 25 pounds during the offseason and why he considers himself in "tip-top" shape as he prepares for his role as closer now that icon Trevor Hoffman has moved to Milwaukee.

As for the Nintendo Wii, Bell often played that with his wife and children at their home in Florida. It wasn’t until the Bells purchased the Wii Fit game and board that he started doing the exercises that helped him get in what he considers the best shape he’s been in since joining the Padres in 2007.

Source