The Tour de France Femmes Avec Zwift will tackle the first trio of Category 1 climbs, Petit Baron, Col du Platzelwasel and Grand Baron, which will have a significant impact on the overall classification.

Highly regarded as the queen of Saturday's stage 7, Kasia Niewiadoma (Canyon-SRAM) said she was overwhelmed by the difficulty of the route.

"Definitely super hard. After previewing stage 7, I have to admit I was overwhelmed. Not overwhelmed in a good way," Nieuwiedma, who is currently in third place overall, 30 seconds behind overall leader Marianne Vos (Jumbo-Visma), told Cycling News.

"I was thinking about being able to handle the climbs around 20 minutes, because the longer the climbs are, the less good I am. So I thought the climb on stage 7 would be around 20 minutes, but it was longer and steeper than I thought it would be."

"I wasn't too keen on it. Thankfully, I had five or six weeks to work on the long climb. So now, with that stage ahead of me, I feel much more comfortable and confident.

"Super hard. It's the queen stage. It feels very brutal."

The 127.1-km route between Celeste and Le Marckstein includes three challenging passes, starting with the Petit Baron, a 9-km climb with an average gradient of 8.1%.

"In my opinion, the first climb is the most difficult. When you get to the hardest climb first, and you're pretty much done, and you're tired, and you think, wow, there are still two more," Nienyadoma said. [If Annemieke van Fruten is having a good day, I wouldn't be surprised if she attacks on the first climb of the Petit Ballon. Like I said, there's the Petit Baron climb, a short descent, and the Col du Platzelwasel climb. You can easily gain 5 minutes on just two climbs, then jump down into the valley, run 10 km, and start climbing again."

The middle climb, the Col du Platzelwasel, is 7.1 km with an average gradient of 8.3%. Niewiadoma said that adequate fueling will be important in this stage.

"In terms of fueling, it's always difficult because it's interesting because you're climbing for 30 minutes and when you're riding hard you can't focus on eating. What I felt in the preview of this stage is how important it is to take care of everything to be able to give your best on the final climb," Nienyadoma said.

"I feel like I could lose this stage not because of lack of power, but because of lack of resupply and hydration. It's a very interesting stage and you have to focus on riding and pushing hard.

The Grand Baron is the longest climb in the Tour de France, peaking at 119.9km. The climb averages a gentle 6.7%, but the final 6km is a steady 8.5%, testing true climbing ability.

Once up the Grand Ballon, there is little rest for the riders as the 8km climb continues to undulate along the ridge until the finish in Le Marquesien.

"I wouldn't be surprised to see the peloton shredded and a group of five or so. The Grand Baron is 15km to the left of the turn, and according to VeloViewer it's probably a short 10km climb, but it drags on for about 15km to the finish. I'm dragging all the way. It's definitely exhausting, and it's going to break you, completely," Nienyadoma said.