The strength required to sing is the reason you find so many mesomorphs in opera—the same body type usually found in football or weight lifting. Mesomorphs are bulky and muscular and tend to gain weight easily. A number of opera singers are obviously no exception.(I'll let Opera Chic photoshop that one.) Nothing a fan doesn't already know, but still a fun read.
Consider four of the top male singers in the world. Placido Domingo stands 6'2" and weighs 225 pounds; Milnes is 6'2", 212 pounds; Martti Talvela 6'7", 250 pounds; and Pavarotti 6'1", about 240 pounds. That's a front four Bear Bryant would covet.
BONUS! From September 29, 1969, Seiji Ozawa falls on his butt:
Seiji Ozawa is a guest conductor with the New York Philharmonic and a second baseman for the Penguins, the orchestra's softball team. Earlier this month, while the Philharmonic was performing at Iowa State, the Penguins took on a fraternity team. The Penguins won the game 9-8 but almost lost a conductor. Ozawa was knocked down by a determined base runner and suffered a fractured coccyx. It's nice that conducting is something you do standing up.