Image 1 of 5 Julian Alaphilippe (Etixx-Quickstep) is interviewed after winning the stage and moving into the yellow jersey (Image credit: Tim de Waele/TDWSport.com) Image 2 of 5 Julian Alaphilippe (Etixx-Quickstep) celebrates stage victory on the podium (Image credit: Tim de Waele/TDWSport.com) Image 3 of 5 The win meant a lot to Julian Alaphilippe (Etixx-Quickstep) today Image 4 of 5 Julian Alaphilippe (Etixx-Quick Step) (Image credit: Tim de Waele/TDWSport.com) Image 5 of 5 Julian Alaphilippe (Etixx-Quickstep) doing a Thomas Voeckler impersonation on his way to victory

After an impressive season that included second place finishes in both Liège - Bastogne - Liège and Flèche Wallonne, and a second overall and the best young rider jersey at the Tour of California, 23-year-old Julian Alaphilippe was never able to regain his early season form, and finally found out why - he had contracted mononucleosis - a disease caused by the Epstein Barr virus that leads to extreme fatigue.

The Frenchman revealed the diagnosis in his Etixx-Quickstep blog entry, noting that his difficulties started when he travelled to Canada for the Montreal and Quebec WorldTour races.

"When I arrived in Canada for the races I immediately had the feeling that something was wrong," Alaphilippe wrote. "I didn't feel really well. But, when you are young, you think it is simply a matter of fatigue and not fully recovering. I didn't really think about it. I tried to do my job. But, from Canada, we flew immediately to Richmond for the UCI World Championship. I spent 15 days there, so for me it was a long period mentally. Sadly, the feeling did not improve. In fact, it felt worse. I was training really hard, but my body didn't respond as I hoped. I rode the Worlds, but since the first pedal stroke I knew it would be bad for me. There was nothing I could do with my condition."

He was diagnosed upon his return to Europe, and said it was likely the result of a recent infection. "For me, it was a mixed feeling. In one way I was upset, because I couldn't finish the season the way I wanted, especially with worlds on a road course I really liked. But, on the other hand, I was relieved. I finally had an answer for why my body was not at the level I expected. It was because of an illness, not because I did something wrong in training or recovery."

Now that he has answers and has plotted his course toward recovery, he has set his sights on next year's Ardennes Classics, where he will race with new teammate Dan Martin.

"I had a few days with the team in meetings in Brussels, and now I will take a small period off before focusing on next season. I want to do well next year. I also had the chance to meet with Dan Martin, a guy who knows the Ardennes Classics well. It was nice to chat with him and discuss our mutual love for those races. We will see what we can do together. I think I can learn a lot from him and can start the 2016 season on the right path with Etixx – Quick-Step."