The 39-year-old 'The Wolf of the Wall Street' star is apparently worried about the gain of weight, reported Daily Star.
"Leo has decided now would be a good time to get back in shape. He's had a big summer of partying and it's showing around his waist. Leo will turn 40 in November and knows that if he doesn't start looking after himself, it'll only get harder as he grows older.
"He's told his celebrity trainer he's got until November to get a body resembling David's (Beckham). Leo's already started his regime which involves early morning paddle boarding followed by two-hour sessions at a gym," a source said.