As you preview the challenging Pyrenees stage of the 2025 Tour de France, incorporate expert insights on what makes this route uniquely demanding for the riders. Discuss the physiological challenges they face, such as altitude, steep climbs, and the impact on endurance. Highlight specific training techniques that top cyclists employ to prepare for these conditions. Additionally, consider including anecdotes or quotes from past competitors who have tackled similar stages. Aim to connect the excitement of the race with the scientific principles behind cycling performance.