Tour de France winner Chris Froome began a series of physiological tests on Monday designed to prove his achievements should not attract suspicion.
The British rider posted a video on his Twitter account, showing him pedalling a bike while linked up to monitors at the GlaxoSmithKline Human Performance Lab in London.
Froome, who followed up his 2013 Tour win with a thrilling victory last month for Team Sky, was forced to endure rumours and abuse during the race -- leading to Sky taking the unusual step of making the 30-year-old`s medical data available.
His impressive ride up La Pierre St Martin in the first mountain stage raised suspicions like his 2013 ride up the gruelling Mont Ventoux and he had urine thrown at him by a spectator during the 14th stage.
"Plenty more testing and analysis to be done, I will be sharing results later in the year," Froome said.
Froome is also using the London lab to try and replicate the conditions expected at next year`s Rio Olympics.
He will lead the team at the Vuelta a Espana which starts on Saturday.