We've already seen world records smashed at the Tokyo Olympics and dozens of athletes post their personal best times.

Norway's Karsten Warholm smashing his own 400m hurdles world record today - shaving off 0.7 seconds - in a time of 45.94.

Warholm broke his own world record in Tokyo

The man who came second in that race, Team USA's Rai Benjamin, also broke the previous world record time with 46.17.

The bronze medallist came home in 46.72 - a time that would have been the fastest in history five weeks ago.

Elaine Thompson Herah broke the Olympic record in the women's 100m while Jasmine Camacho-Quinn did likewise in the women's 100m hurdles.

The Polish mixed 4x400m relay team have also twice broke the Olympic record so far at the Tokyo Games.

More records look likely to tumble before the Olympics are over and there has been suggestions the track has something to do with that.

Thompson Herah set a new Olympic Record in the women's 100m

Track designer for Mondo, Andrea Vallauri, suggested the surface is making more of a difference than people realise.

"Every time there is an Olympic Games we try to improve the formulation of the material and Tokyo has been no different," he said. 

"The track is very thin, 14mm. But we have added a new element: these rubber granules.

"In the lower layer of the track is this hexagonal design that creates these small pockets of air.

"They not only provide shock absorption but give some energy return; at the same time a trampoline effect. We have improved this combination and this is why we are seeing the track has improved performance.

"In Rio the track was called WS. This new one is called WSTY, for Tokyo. It's the latest evolution of the track.

"It is completely within the rules but it is also what we were asked to provide; two components.

Warholm ripped his shirt in delight after smashing his world record

"To protect the health of the athletes, to avoid trauma, but it should also give them a push, let me say it like that.

"In lab testing we can see the improvement. It is difficult to say exactly but maybe a one or two per cent advantage.

"It is all prefabricated so every lane is the same, and the run-ups for the long and triple jumps also. The production is the same as a Formula One tyre."