A publicity event for new Team Sky sponsor IG Markets was overshadowed when a male competitor collapsed during the event in London on Friday afternoon.
An unidentified male had been involved in the IG Markets Square Mile Challenge, which gave members of the public the opportunity to race against Sky riders Brad Wiggins, Russell Downing, Geraint Thomas and Ben Swift on stationary bikes over a mile (1,609 metres).
The incident occurred just before 1pm near
Matthew Walters had been part of the same race and only moments earlier had managed to defeat Wiggins over the one-mile distance.
"I just saw the guy come off the bike. He was only two bikes down from me and he basically fell into someone's arms," Walters told BikeRadar. "It's a lot harder than the turbo trainer so I can imagine it would be a really difficult challenge if you weren't in great shape.
"Apparently they couldn't pick up a pulse so they began CPR on him straight away.
"Obviously, you don't want to see these sorts of things happen at events like this, because they're so important for cycling."
The event at
"I only saw what everyone else saw, so I'm not exactly sure what's happened" Wiggins told BikeRadar. "It's just a sad way to end the day."