Chris Froome has insisted that he is on a "personal mission" to show that the sport has changed after once again answering questions about doping.

The Team Sky rider, who took the yellow jersey at the Tour de France yesterday, believes that he can change perceptions about cycling by continuing to perform impressively without using performance enhancing drugs.

When asked if he was riding clean in the race, Froome responded: "100%. I know the results I get are not going to be stripped 10 years down the line.

"Results now are definitely a lot more credible. The questions should be asked about people who were winning races maybe five, 10 years ago when we know doping was more prevalent. For me it is a bit of a personal mission to show that the sport has changed."

Team Sky are targeting a second victory in a row in the race following the success enjoyed by Sir Bradley Wiggins last year.