Olympic 400m hurdles champion Karsten Warholm says carbon-technology shoes are “hurting athletes’ credibility”.

After winning gold, Warholm criticised the thick-soled Nike shoes of second-placed American Rai Benjamin, saying they act like a “trampoline” and diminish credibility, despite also wearing spikes with a carbon plate to improve performance.

“What I said was misunderstood in some way, because I had one comment about it after the race and it just blew up and that wasn’t my plan at all,” said Warholm.

“To be honest I don’t know if that shoe [Nike] is the best shoe. My shoe [Puma] is maybe just as good, but that’s not what it is about, necessarily. I haven’t done the science.

“When somebody does a great performance now, everybody will question if it’s the shoe – and that is the credibility problem.”

Many athletes now wear super-light shoes containing a rigid plate and unique foam that lend a propulsive sensation to every stride.

Critics claim the shoes, first developed by Nike, are the equivalent of mechanical doping. Former marathon world record holder Tegla Loroupe stated athletes using the shoe technology are “cheating” and that it is “almost like doping”.

Supporters, though, hail them as a revolutionary advance.

“People sitting at home, I don’t want them to feel like they’ve been fooled or tricked. I want there to be credibility,” added Warholm.

“Hopefully somebody is doing the research and hopefully World Athletics are there to protect both athletes but also the audience.”