Yates came into the Tour with very little racing in the legs after only racing the Critérium du Dauphiné before the French Grand Tour, with his team revealing that he'd also suffered from a mystery illness a few weeks before the Tour.
"He had some kind of parasite - there was a lot of vomiting - we think from fountain water he drank." said his team according to BBC Sport.
"It knocked him for six - he had 10 days completely off the bike, then two or three weeks when he was certainly on restricted training. And that was right at the time when we are going hard on the training."
This makes his ride in the first week of the Tour even more impressive after taking the race lead from Julian Alaphilippe (Deceuninck - Quick-Step), who was penalised for taking a bottle inside the last 20km of stage five.
Yates looked in superb form on stage two when he attacked across to Alaphilippe, who went on to take the stage win, and Marc Hirschi (Team Sunweb).
The race was then rather simple to control for Yates' team in the days after him unexpectedly going into yellow.
On the first day of the Pyrenees the other riders going for the general classification peppered the last climb with attacks but every time they came back together Yates managed to get back on.
While he couldn't follow any moves of the big favourites, he rode up the climb at his own pace and finished with them and kept yellow.
Stage nine saw Yates crack and slip out of yellow and dropped to eighth overall at just over a minute down on the new leader, Primož Roglič (Jumbo-Visma).
The British climber will likely now target stages in the coming mountain stages that pepper the end of week two and the final week of the race as he looks to improve his condition as he races on.
“I did everything I could. I said from the very beginning, even before the Tour started, that I wasn’t at 100 per cent,” Yates said after the finish of stage nine. “And I think we did well. We hung on for as long as we could. And yeah, there are a couple of guys going better than me. So I did the best I could and I think we can be proud.
“It’s a big honour riding in yellow,” he added. “It was good fun while it lasted.”
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