Kilian Jornet drops out of 24-hour world record attempt after 11 hours

The runner left the track with extreme dizziness. Five runners remain

Yiannis Kouros suggests Kilian Jornet is shoe doping for 24-hour world record attempt

Hours before Jornet began his 24-hour world record attempt, Yiannis Kouros ranted on Facebook about cheater shoes

Breaking 30: climbing 1,000m in 30 minutes or less

In this Salomon Running video, viewers will see elite Swiss runner RĂ©mi Bonnet chase the elusive 30-minute barrier for a vertical kilometre