Athletics has become "boring" for many young people and needs to undergo "radical" changes if it is to survive, says the head of the sport Lord Coe.
In a documentary, to be broadcast on BBC One at 13:00 GMT on Saturday, Coe suggests the season needs extending and the World Championships shortening.
"In four years I want us to look completely different," he said.
"This is about survival, doing radical things. I have to put to the back of my mind it's an unpopular thing to do."
Coe, who took over as the head of the International Association of Athletics Federations in August 2015, was talking to former middle-distance rival and BBC Sport commentator Steve Cram.
He added: "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."
...but more competition
However, Coe, who won Olympic 1500m gold in 1980 and 1984, also suggested that "there isn't enough athletics" across 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."
He also wants to see more head-to-head races among the elite athletes, saying: "Agents and managers at the beginning of the season say 'our guy is going to have a quiet year'.
"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."
Coe also revealed he is working to improve athletics' presence on social media platforms.
"We've been really bad at that," he conceded. "If you look at football, tennis, American sports, they've all got great social media platforms. We're only scratching the surface of that in our sport."
You can watch the full programme: Can Seb Coe Save Athletics? on Saturday, 26 March at 13:00 GMT on BBC One.