Which is the correct lead time before athletic practice to hydrate with 20 oz of water?

• A. 15 minutes before
• B. 2-3 hours
• C. 4-6 hours
• D. Immediately after waking

Answer: (B)

Hydration should be established during the hours leading up to exercise to ensure you start activity in a well-hydrated state and without GI distress. Drinking about 20 oz (roughly 600 ml) about 2–3 hours before practice gives enough time for the stomach to empty and for fluids to be absorbed, so your plasma volume is maintained as you begin sweating.

Waiting only 15 minutes before practice doesn’t leave time for the stomach to empty or for fluids to be absorbed, which can lead to bloating, cramps, or needing to urinate during activity. Drinking too early, such as 4–6 hours before, risks returning toward baseline hydration or even becoming dehydrated again by start time, and you miss the benefit of maintaining hydration into the start of exercise. Simply after waking doesn’t target the pre-practice window either; you want the hydration plan to occur in the hours before you exercise, especially for morning sessions.

So, 2–3 hours before is the best lead time to hydrate with 20 oz of water.