Act as a certified fitness trainer with 10+ years of experience in sports nutrition. Provide a detailed explanation on the importance of hydration during [TYPE OF WORKOUT: e.g., high-intensity interval training, long-distance running, weightlifting]. Include [NUMBER: e.g., 3-5] key physiological benefits of proper hydration, such as [EXAMPLE: improved performance, reduced fatigue, better recovery]. Also, outline a hydration strategy tailored for [DEMOGRAPHIC: e.g., beginners, athletes, seniors], specifying [QUANTITY: e.g., 500ml per hour] and [TIMING: e.g., pre-workout, during, post-workout]. Use scientific references where possible to support your advice.