Sebastian Coe wants athletics to undergo a major overhaul in order to secure its long-term future.
The IAAF president fears the sport is losing its appeal and said urgent action was needed to revamp major events to make them more engaging for spectators.
"In four years I want us to look completely different," Coe, who won two 1,500-metre Olympic gold medals in the 1980s, told the BBC.
"This is about survival, doing radical things. I have to put to the back of my mind it's an unpopular thing to do.
"Has what we are watching changed dramatically since we were competing? Yes, in little ways.
"But people were prepared back in 1983 to sit through nine or 10 days of a World Championships. They are not going to do that now.
"We have to be realistic. Will we have a World Championships format that is shorter? No, not straight away. Will we have that in five years? We have to."
Coe suggested the entire athletics calendar will need looking at to keep it at the top of the agenda throughout the year.
"We go from September to May when there's not a lot to be talking or writing about," he said. "We have got to remedy that and to look at extending the season.
"We probably have to go into climates where we can compete and develop those markets."
And the 59-year-old, who has repeatedly had to underline the IAAF's commitment to ridding athletics of doping cheats, cited the importance of the sport's biggest names being involved regularly.
"Agents and managers at the beginning of the season say 'our guy is going to have a quiet year'," he added.
"It's a bit like selling season tickets at Barcelona and saying Lionel Messi is only going to play one in three games. You don't do that."