Robert Downey Jr. at the OscarsWhen a superstar Hollywood actor accepts a role to play a superstar literary figure, it's got to put them under a lot of pressure to measure up to a character with so much baggage. And while going to extremes to lose weight for a role is par for the course, Robert Downey Jr. has a kinda unusual personal trainer for his upcoming roll as Sherlock Holmes. Apparently, Chris Martin is a Sherlock Holmes junkie and has told Downey that he must lose weight to look "guant" for the role -- like the Sherlock he's always pictured.

According to Martin: "You've got to be gaunt. You've got to be a skinny as you possibly can to play Holmes."

Losing an unhealthy amount of weight is a pretty serious favor to ask from someone, but we suppose that ruining thousands of people's mental images by appearing as a pudgy Sherlock Holmes is a pretty serious acting faux-pas. Apparently Downey is taking the emotions of Coldplay's front man seriously: "Every time I'm reaching for a muffin I just think about Chris Martin and skip the snack. It's been tough."

Obviously, the Chris Martin technique doesn't work for everyone. Especially since most of us can't afford to have a rockstar as a personal trainer. We might all have to settle for an out of work actor who does commercials every now and then.

[via Blackbook]