49ers ILB Patrick Willis took up Mixed Martial Arts this offseason and kept his weight at 238 pounds, but still dropped two belt sizes.
A more fit, faster Willis (he ran 4.37 coming out for the '07 draft) is a scary proposition, to say the least. MMA could also help him use his hands better. He's a terrific bet to regain his spot at the top of the NFL tackle ranks.
Source: Profootballtalk on NBC Sports