Following the recent stories about doping in sport, Dr Xand van Tulleken investigated performance-enhancing drugs for BBC2's Horizon programme.
As part of the programme, Dr Mayur Ranchordas, sports nutritionist at Sheffield Hallam, discussed the impact caffeine can have on sporting performance - with the presenters taking part in a live test to witness the impact for themselves.
Dr Nick Tiller is a BASES-accredited physiologist and module leader in Applied...