A study claims many athletic records are approaching their limits
Time runs out for world records
World records in many athletic events are peaking - and will not be broken unless athletes take drugs, say researchers.
The study, "Are there limits to running world records?", suggests faster times may prove elusive.
The current women's 1500m record may never be broken, said Professor Alan Nevill, without fundamental changes to the genetic structure of human beings.
Prof Nevill says many running records are "already nearing their limits".
The paper, co-written by Professor Nevill at the University of Wolverhampton and Professor Greg Whyte from the English Institute of Sports, challenges previous scientific research that there was no limit to human performance and that women would eventually run as fast as men.
Professors Nevill and Whyte re-interpreted data of previous performances and concluded that records set to plateau .
"For the first time we have identified that there could be a limit to performance and that world records will not continue to rise," said Professor Nevill of the University of Wolverhampton.
"Many of the established men and women's middle and long distance running records are already nearing their limits.