Your exercise level significantly impacts hydration needs. Select your activity level for a personalized target.
Based on Institute of Medicine (IOM) Dietary Reference Intakes for Water (2005) and Harvard T.H. Chan School of Public Health guidelines.
Clear, evidence-informed answers about daily hydration.
General guidelines: Light activity +350 mL, Moderate +700 mL, Heavy +1000 mL daily. During exercise: drink 250–500 mL 30 minutes before, then 150–250 mL every 15–20 minutes during activity. Replace 150% of sweat loss after.
Yes. Light walking (1–3 days/week) falls under "Light activity" (+350 mL). If you walk briskly for 30+ minutes most days, consider "Moderate" (+700 mL).
For workouts under 60 minutes at moderate intensity, pre-hydration and post-hydration are usually sufficient. For longer or intense sessions, sip 150–250 mL every 15–20 minutes during exercise.
For exercise over 60 minutes, or in hot conditions, or if you are a salty sweater, yes — add electrolytes. For shorter sessions, water is usually fine. See our Water vs Electrolytes guide.