Of all the factors that have contributed to Ray Lewis' longevity (talent, drive, luck), perhaps none is as important as fitness. The Baltimore Ravens linebacker and future Hall of Famer is a notorious workout fiend, and it is somewhat absurd that at 37, he is still evolving with the game.

Lewis recently showed off his muscle in a gym session with the rapper Nelly, who is filming a workout series with athletes and other stars called "Celebrity Sweat." Nelly, who is about six months older than than Lewis, appears to keep up for most of the workout, but by the end he is too gassed to continue.

Ray Lewis' workout, and many more, can be found at the "Celebrity Sweat" website.

(H/T to Late For Work)

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