Nick Willis intends to run only the 800m at the Commonwealth Games in Delhi, and won't be defending the 1500m title he won in Melbourne.
Willis, the silver medalist at the Beijing Olympic Games in 2008, made his announcement before defending his one mile title at the Boston Indoor Games at the weekend.
Willis won the race in 3m 55.26, 0.40s ahead of American Will Leer.
"I won't be doing the 1500m," he told universalsports.com.
"I will be doing the 800m. I've been talking to a few other sprinters on the circuit the last few years, Debbie Ferguson in particular, and I ask, 'How do you continue to run so fast as you get older because a lot of people say as you age, you get slower?'
"She said, 'No, they neglect that side of their training as they get older'. So by stepping down to the 800m, it's a way to give me more accountability to continue working on my speed so I can still be one of the best 1500-metre runners when I get into my old age," he said.
Willis had no qualms about competing in Delhi and said it was a priority for him.
"There are a billion people there [India] and it will be great to be able to expose, and help promote, track and field there and to make sure the Commonwealth Games gets the respect that it deserves," he said.
Despite his indoor success in his first major meeting back from his hip surgery, Willis said he would not be competing in the world indoor championships. He has a race in Birmingham, a 1500m in Australia on March 4 and then an 800m in New Zealand on March 13.
He said he would not race in the world indoors because he didn't want to have to peak twice in the same season.
Following the line of Jack Lovelock, who said he could never run more than one big race a year, Willis said: "I don't think it's healthy to have two over-serious championships in the same season.
"With it [the Commonwealth Games] being in October, I would peak too early because emotionally it would be hard to told it again until October.
"How I perform in New Delhi is going to dictate the grade for my year so I need to make sure I'm at my best in October," he said.