Double Olympic champion Hicham El Guerrouj is out of next month's World Championships in Helsinki.
El Guerrouj is set to retire at the end of 2006
The 31-year-old four-time world champion picked up a virus in May.
And the Moroccan, who won the 1500m and 5,000m in Athens last year and has not raced since, told French newspaper L'Equipe he was taking the season off.
El Guerrouj said: "No, I will not race [this season]. It was not an easy decision to take. I took my decision one month ago."
El Guerrouj said a never-ending series of public appearances after his Athens triumph had taken its toll.
He plans to resume training in August and run again in 2006 before hanging up his spikes.
"I've got nothing to prove. Everything I do next year will be a bonus," he said.
He named Portugal's Olympic bronze medallist Rui Silva as his favourite to succeed him in Helsinki.
But he also believes Ukraine's Ivan Heshko and Kenya's Komen Kipchirchir are in the running for the world title.
El Guerrouj won the 1500m world title in 1997, 1999, 2001 and 2003.
He was silver medallist in 1995 and also won the 5,000m silver medal in 2003.
His 3min 26sec run in 1998 still stands as the 1500m world record.