Whats the optimal hydration strategy for multi-session training, and are there any differences in hydration needs between high-intensity interval training and low-intensity endurance rides? Should cyclists prioritize water intake over electrolyte supplements, or is it a combination of both that yields the best performance results? How do factors such as climate, terrain, and individual sweat rate impact hydration needs, and what are some effective methods for monitoring and adjusting hydration levels during training? Are there any specific hydration products or tools that are particularly well-suited for cyclists, or can general sports hydration products suffice?