Prof David Paterson, of Oxford University, one of the world's foremost physiologists, explained his views to the Otago Daily Times when he was in Dunedin last week.
He believes that three important barriers will be broken in his lifetime: 1min 40sec for the 800m, 3min 40sec for the mile and 2hr for the marathon.
David Rudisha (Kenya) broke the world record for the 800m when he ran 1min 41.01sec in Rieti, Italy, on August 29, 2010.
Peter Snell broke the world record when he ran 800m in 1min 44.30sec on a grass track at Lancaster Park on February 3, 1962. It is still the New Zealand record.
"Snell was capable of running the second lap under 50 seconds and that is why he was so good," Paterson said.
"I have studied pictures of him winning at the Rome and Tokyo Olympics and it is amazing to see how composed he was at finish compared to everyone else behind him. He was ahead of his time.
"He had that phenomenal explosive kick. The only other athlete with that was John Walker in his early days.
"Peter was shorter and was almost built like a sprinter and was very powerful."
The time Snell ran on a grass track at Lancaster Park in 1962 would have won an 800m gold medal at Beijing.
"It is still the New Zealand record 50 years later and that gives us an idea of how good he was," Paterson said.
"In my lifetime, I would like to see the world record fall below 1min 40sec for 800m. It would mean running two sub-50-second 400m back to back."
Paterson said a sub-1min 40sec time would put the 800m alongside the mile and the marathon as one of the great middle- and long-distance events in world athletics.
It would be like Roger Bannister running the sub-4min mile for the first time. A sub-2hr marathon would be another hallmark for athletics.
Hicham El Guerrouj (Morocco) broke the world mile record when he ran 3min 43.13sec in Rome on July 7, 1999.
New Zealand's Sir John Walker broke the 3min 50sec barrier when he ran 3min 49.4sec in Gottenberg, Sweden, on August 12, 1975.
The next barrier is to break 3min 40sec.
"That would be incredible," Paterson said. "I will ask Roger Bannister where he thinks the mile will end up when I see him next."
The great New Zealand middle- and long-distance coach Arthur Lydiard predicted in the early 1970s that the 2hr barrier in the marathon would never be broken in his lifetime. It still has not been broken 40 years later.
Geoff Mutai (Kenya) ran the world-record time of 2hr 03min 02sec when winning the Boston marathon last year.
"I think that will happen because of advanced training and better diet manipulation," Paterson said.
"Marathon times have come down dramatically and have been helped by glucose drinks.
"Back in the 1950s and 1960s, you just got a wet old sponge, if you were lucky."
Women's marathon times had come down dramatically.
"Women are closing in on men's times," Paterson said.
"They have made rapid progress.
"In power events, men will always win because of testosterone, but as the distance gets longer, the gap between the genders gets smaller."
The women's world record for the marathon, 2hr 15min 25sec, was run by Paula Radcliffe (Great Britain) on April 13, 2003 in London.
