# How Much Water to Drink When You Work Out (India Guide) > How much water to drink for the gym: daily needs, what to drink before, during and after a workout, a simple sweat test, Indian heat, ORS vs coconut water. - URL: https://www.mygymgate.com/blog/how-much-water-to-drink-gym/ - Category: Fitness - Published: 2026-10-06 - Publisher: MyGymGate (https://www.mygymgate.com) Most healthy adults need roughly 2 to 3.7 litres of total water a day from drinks and food, and more on training days and in Indian heat. Around a workout, drink normally through the day, sip when thirsty during the session, and replace what you lost afterwards, which you can measure by weighing yourself before and after. For a typical one-hour gym session, plain water is all most people need. Get a starting number from the [water intake calculator](/tools/water-intake-calculator/), then fine-tune it with the sweat test below. ## How much water do you need in a day? Three reputable bodies give similar ballpark figures. | Source | Women | Men | Notes | |---|---|---|---| | [EFSA (2010)](https://doi.org/10.2903/j.efsa.2010.1459) adequate intake | 2.0 L | 2.5 L | Total water from drinks and food, for moderate temperatures and moderate activity | | [US National Academies (2004)](https://www.nationalacademies.org/news/report-sets-dietary-intake-levels-for-water-salt-and-potassium-to-maintain-health-and-reduce-chronic-disease-risk) adequate intake | about 2.7 L | about 3.7 L | Total water; about 80% comes from drinks and 20% from food | | [ICMR-NIN Dietary Guidelines for Indians 2024](https://nin.res.in/dietaryguidelines/pdfjs/locale/DGI_2024.pdf) | about 8 glasses (2 L) | about 8 glasses (2 L) | Drinking water including beverages; more in very hot weather and with vigorous activity | The numbers differ partly because the ICMR figure is what you drink, while EFSA and US figures include water in food like dal, rice, curd and fruit. None is a hard target. The US report says most healthy people meet their needs by letting thirst guide them, while very active people in constant heat can need six litres or more. So treat 2 to 3 litres of drinks as a normal base for an adult, and add to it for training and heat. ## How much should you drink before, during and after a workout? The [American College of Sports Medicine position stand on exercise and fluid replacement](https://pubmed.ncbi.nlm.nih.gov/17277604/) (2007) is still the standard reference. Its goals are simple: start exercise well hydrated, avoid losing more than 2% of your body weight as fluid during it, and replace the deficit afterwards. ### Before ACSM suggests drinking about 5 to 7 ml per kg of body weight at least 4 hours before exercise. For a 70 kg person that's roughly 350 to 500 ml, so a glass or two with your pre-workout meal. If you aren't passing urine or it is dark, add another 3 to 5 ml per kg about 2 hours before. For a 6 am session, a glass of water when you wake up does the job. ### During ACSM's aim is to keep fluid loss under 2% of body weight. For a 70 kg person that's 1.4 kg. Its often-quoted range is around 0.4 to 0.8 litres an hour, with lighter people in cooler conditions at the low end and bigger people in heat at the high end. For most weight sessions under an hour, sipping water between sets is enough. ACSM says electrolyte and carbohydrate drinks beat water only "under certain circumstances", such as long or very sweaty sessions. ### After Replace roughly 1.5 litres of fluid for every kilogram you lost, spread over the next few hours, as ACSM advises. The extra 50% covers urine you pass while rehydrating. A normal salted meal puts back the sodium. ## How do you measure your sweat rate? Sweat rates vary a lot from person to person. A [2017 review of sweat testing](https://pmc.ncbi.nlm.nih.gov/articles/PMC5371639/) found whole-body sweating rates in athletes typically range from about 0.5 to 2.0 litres an hour, occasionally above 3. It also says the simplest accurate method is the change in body weight during exercise, corrected for what you drink and any urine you pass. 1. Pass urine, then weigh yourself in minimal, dry clothing. 2. Train as normal. Note how much you drink (a marked bottle helps). 3. Don't use the toilet during the session if you can help it. 4. Towel off, then weigh yourself again in the same dry clothing. 5. Sweat lost (litres) = weight before − weight after + water drunk. 6. Divide by the session length in hours to get your sweat rate. Each kilogram lost is roughly one litre of fluid. ### A worked example (hypothetical) Say Arjun weighs 72.0 kg before a 60-minute session in a warm gym and 71.2 kg after. He drank 500 ml during it and didn't use the toilet. - Weight lost: 72.0 − 71.2 = 0.8 kg (about 0.8 L) - Sweat lost: 0.8 + 0.5 = **1.3 L in one hour** - Body weight lost as a percentage: 0.8 ÷ 72 × 100 = about 1.1%, under the 2% line (which for him is 1.44 kg) - To rehydrate: 0.8 × 1.5 = **about 1.2 L over the next few hours** Repeat the test in summer and winter; the numbers will differ. Sweat trapped in clothing makes the result a little low, so use dry clothes for both weigh-ins. ## Does Indian heat and humidity change things? Yes. Heat raises sweat rate, and humid air slows sweat evaporating from your skin, so it cools you less while you keep losing fluid. A non-AC gym in Chennai in June is a different place from the same gym in January. India's [public health advisory on extreme heat](https://ncdc.mohfw.gov.in/uploads/pdf/5.%20Public%20Health%20Advisory_Extreme%20HeatHeatwave.pdf) from NCDC (Ministry of Health and Family Welfare) says to drink water often even if you're not thirsty, use ORS and homemade drinks like lemon water and buttermilk or lassi, and avoid strenuous activity outdoors in the afternoon (it names 12 noon to 3 pm for being out in the sun). What that means for training: - Move outdoor runs and cycling to early morning or evening in summer - Start the session already hydrated, with pale urine - On very hot days, lower the intensity. Zone 2 work is easier to keep sensible in heat; see [zone 2 cardio for fat loss](/blog/zone-2-cardio-fat-loss/) and set your range with the [heart rate zone calculator](/tools/heart-rate-zone-calculator/) ## Water, ORS, sports drinks, nimbu pani or coconut water? Sweat contains salt. The same review puts whole-body sweat sodium at roughly 10 to 70 mmol per litre, about 230 to 1,600 mg of sodium per litre of sweat. For gym-goers a meal usually replaces it. Salty drinks matter more after long, very sweaty sessions or when you can't eat soon. | Drink (about 250 ml) | Sodium | Sugar/energy | Best use | |---|---|---|---| | Plain water | Almost none | 0 kcal | Normal gym sessions, daily drinking | | WHO ORS (reduced osmolarity) | About 430 mg (75 mmol/L) | About 3.4 g glucose | Diarrhoea, vomiting, heat cramps, heavy fluid loss | | Sports drink | About 60 to 170 mg (23 to 69 mg/100 ml) | 10 to 20 g carbohydrate | Sessions over about an hour, hard sweaty training | | Tender coconut water | Varies; USDA lists about 260 mg | About 40 to 50 kcal | Pleasant drink with potassium; not needed for most sessions | | Nimbu pani / buttermilk (homemade) | Depends on how much salt you add | Depends on sugar | Everyday drink in summer, especially unsweetened | Where the numbers come from: the [WHO ORS formula](https://www.who.int/publications/i/item/WHO-FCH-CAH-06.1) has 75 mmol/L sodium and 13.5 g/L glucose. Typical sports drinks, per the [Australian Institute of Sport](https://www.ausport.gov.au/ais/nutrition/supplements/group_a/sports-foods2/sports-drink/what-is-it), have 4 to 8% carbohydrate and 23 to 69 mg sodium per 100 ml. [USDA FoodData Central](https://fdc.nal.usda.gov/food-details/170174/nutrients) lists coconut water at about 105 mg sodium, 250 mg potassium and 19 kcal per 100 g, though real nuts vary; ICMR-NIN gives 15 kcal per 100 ml. A few honest notes: - **ORS is a medical rehydration product.** It's the right thing for diarrhoea or heat illness. It isn't a daily gym drink. When you buy it, check the pack says it follows the WHO formula, since many flavoured "electrolyte" drinks are mostly sugar. - **Sports drinks are fuel plus a little salt.** Useful for long sessions or matches. For a 45-minute weights workout while cutting, they're mostly extra calories to fit into your [calorie deficit](/blog/calorie-deficit-maintenance-calories/); the [calorie calculator](/tools/calorie-calculator/) gives you that budget. - **Coconut water isn't magic.** ICMR-NIN calls it a good hydrating drink but says people prone to high potassium, as in kidney and heart disease, should avoid it. - **Nimbu pani and chaas are fine.** ICMR-NIN lists buttermilk, lemon water and coconut water as good alternatives to soft drinks. Go easy on sugar. ## What are the signs of dehydration? The [NHS](https://www.nhs.uk/conditions/dehydration/) lists these: - Feeling thirsty - Dark yellow, strong-smelling urine - Peeing less often than usual - Feeling dizzy or light-headed - Headache and tiredness - Dry mouth, lips and tongue ### Is urine colour a good guide? As a rough check, yes. The NHS advice is to drink enough that your pee is pale. But B-vitamin supplements and some foods change the colour, and morning urine is usually darker, so treat it as a hint, not a test. ## Can you drink too much water? Yes. Drinking far more than you sweat out, especially fast and during long exercise, dilutes the sodium in your blood. This is exercise-associated hyponatraemia. The [2015 international consensus statement](https://pubmed.ncbi.nlm.nih.gov/26102445/) on it names sustained, excessive intake of water, sports drinks or other fluids as the main cause, and recommends drinking when thirsty as the safest strategy. As the [ScienceDaily summary](https://www.sciencedaily.com/releases/2015/06/150629100926.htm) of the statement notes, it can cause headache, vomiting, confusion or seizures from brain swelling, and can be fatal without prompt treatment. If you weigh more after a long session than before, you drank more than you needed. Sports drinks don't protect you; they're still mostly water. Overdrinking is rare in a one-hour gym session. The risk is higher in long runs, hikes and "drink 5 litres a day" challenges where people force water down. ## Who should ask a doctor first? Check with your doctor before changing your fluid intake, or using ORS or coconut water regularly, if you: - Have kidney disease or heart failure, or have been told to limit fluids or salt - Take diuretics (water tablets) or other blood pressure medicines - Have diabetes, especially if you're considering sugary sports drinks - Are pregnant or breastfeeding - Are older, or training a child or teenager under 18 in heat Get urgent help (call 108 or 112) if someone becomes confused, faints or has a seizure during heat or exercise. That can be heatstroke or severe hyponatraemia. ## The short version - Base: about 2 to 3 litres of drinks a day for most adults, more on training days and in heat - Before training: a glass or two of water in the hours before - During: sip when thirsty; try to lose less than 2% of body weight - After: drink about 1.5 L for each kg lost, with a normal salted meal - Do the weigh-in sweat test once in summer and once in winter - Plain water is enough for most gym sessions; ORS is for illness and heavy losses - Pale urine is good; gaining weight during a long session means you overdrank - Check with a doctor if you have kidney, heart or blood pressure issues New to training? The [beginner gym workout plan for India](/blog/beginner-gym-workout-plan-india/) uses sessions where plain water is enough. This is general information, not medical advice. ## Useful links - [EFSA (2010), Scientific Opinion on Dietary Reference Values for water](https://doi.org/10.2903/j.efsa.2010.1459) - [US National Academies (2004), report on water, salt and potassium intakes](https://www.nationalacademies.org/news/report-sets-dietary-intake-levels-for-water-salt-and-potassium-to-maintain-health-and-reduce-chronic-disease-risk) - [ICMR-NIN, Dietary Guidelines for Indians 2024, Guideline 14 (PDF)](https://nin.res.in/dietaryguidelines/pdfjs/locale/DGI_2024.pdf) - [ACSM position stand (2007), Exercise and fluid replacement](https://pubmed.ncbi.nlm.nih.gov/17277604/) - [Baker (2017), Sweating rate and sweat sodium concentration in athletes](https://pmc.ncbi.nlm.nih.gov/articles/PMC5371639/) - [Hew-Butler et al. (2015), Exercise-associated hyponatremia consensus statement](https://pubmed.ncbi.nlm.nih.gov/26102445/) - [NCDC/MoHFW, Public health advisory on extreme heat (PDF)](https://ncdc.mohfw.gov.in/uploads/pdf/5.%20Public%20Health%20Advisory_Extreme%20HeatHeatwave.pdf) - [WHO, Oral rehydration salts: production of the new ORS](https://www.who.int/publications/i/item/WHO-FCH-CAH-06.1) - [Australian Institute of Sport, Sports drinks](https://www.ausport.gov.au/ais/nutrition/supplements/group_a/sports-foods2/sports-drink/what-is-it) - [NHS, Dehydration](https://www.nhs.uk/conditions/dehydration/) *Cover photo: [Fitness Male](https://stocksnap.io/photo/fitness-male-C026SHQGNJ) by [Direct Media](https://stocksnap.io/author/145556), CC0, via stocksnap.* ## Frequently asked questions ### Should I drink water during a gym workout? Yes, take small sips when you feel thirsty, especially between sets or in a hot gym. For a typical 45 to 75 minute session, plain water is enough for most people. You don't need to force down a full bottle on a schedule. ### Is 4 litres of water a day too much? For a healthy adult who trains hard in Indian summer heat, 4 litres of total fluid can be reasonable. For a lightly active person in an air-conditioned office, it is more than needed. Healthy kidneys handle extra water spread across the day, but drinking large amounts quickly, especially during long exercise, can lower blood sodium. ### Do tea and coffee count towards daily water intake? Yes. The US National Academies counted caffeinated drinks in total water intake. ICMR-NIN advises keeping caffeine under about 300 mg a day, and India's heatwave advisory suggests avoiding tea and coffee in extreme heat, so don't make them your main fluid. ### Is coconut water better than plain water after the gym? Not for most gym sessions. Coconut water is a pleasant drink with some potassium and a little sugar, but plain water plus your next meal rehydrates you just as well after a normal workout. People with kidney or heart disease who are prone to high potassium should avoid it, as ICMR-NIN notes.