As the sun rose over Mumbai this morning, thousands of runners hit the streets for the Tata Mumbai Marathon 2026, chasing personal bests, finish-line highs and that unmatched runner's adrenaline. Amid the cheers, pounding footsteps and early-morning energy, one crucial factor quietly decides race-day success: hydration.

When and how much water you should consume during marathon
According to Sameera Sheikh, a microbiologist and sports nutritionist with over 11 years of experience, hydration during a marathon isn’t about gulping water randomly; it’s about timing, balance and listening to your body. She explains that runners should start preparing well before the starting gun goes off.
Before the race, Sameera recommends drinking around 400–600 ml of water about 2–3 hours prior, allowing the body to absorb fluids without discomfort. Closer to the start line, 150–250 ml about 15–20 minutes before the race helps top up hydration levels without feeling heavy.

Once the run is underway, consistency is key. “During the marathon, aim for 150–250 ml every 20–30 minutes, especially if you’re running longer distances,” Sameera advises. For runs exceeding 90 minutes, plain water alone may not be enough. This is where electrolytes and isotonic drinks play a vital role, helping replace lost sodium, potassium and magnesium while also supplying quick energy through carbohydrates.
She strongly cautions runners against waiting until they feel thirsty, as thirst is often a late signal of dehydration. At the same time, over-drinking plain water should be avoided, as it can dilute sodium levels in the body and lead to imbalance.

After the race, hydration doesn’t stop. Sameera suggests sipping water gradually along with electrolytes to aid recovery, replenish lost fluids and reduce post-run fatigue.
In a marathon as demanding as Mumbai’s, hydration isn’t just supportive; it’s strategic. Drink smart, fuel right and let every step count.