Sports drinks vs water: which one do you need?

2026-10-30

For most people, most of the time, water is the right drink. A sports drink only earns its place when you exercise hard for more than about an hour, especially in the heat or if you sweat a lot, or in long endurance events where your muscles need fuel along the way. For a 30-minute jog, a gym session or a day at the office, a sports drink is mostly sugar water with a bit of salt. It hydrates you no better than plain water, and it adds sugar you probably don't need.

What's actually in a sports drink

A classic sports drink has three ingredients that matter:

Water, which does the actual hydrating.
Carbohydrate (sugars such as glucose, sucrose or fructose), which gives your muscles fuel during long exercise.
Electrolytes, mainly sodium and a little potassium, which replace some of what you lose in sweat and help your body hold on to the fluid.

That's it. Colors, flavors and "performance" claims don't change the basic recipe.

At rest, the extra ingredients make little difference. In a 2016 trial that compared how well different drinks were retained by people who weren't exercising, a sports drink performed the same as still water. The benefits only show up when you're losing a lot of fluid and burning through your carbohydrate stores.

When water is enough

Water is all you need for:

Exercise under about 60 minutes at easy to moderate intensity: walking, a short run, a typical gym session, yoga, a swim.
Everyday life: work, school, errands, watching sports rather than playing them.
Short, hard sessions like a 45-minute spin class. You'll sweat, but your carbohydrate stores easily cover an hour of effort, and your next meal will replace the salt.

The American College of Sports Medicine's position stand on fluid replacement recommends drinking enough to avoid losing too much body weight during exercise, without overdoing it. Our guide to hydration before, during and after exercise covers that in detail.

When a sports drink helps

Long or intense sessions

Once you go beyond about an hour of continuous hard effort, carbohydrate during exercise starts to matter. A widely cited consensus review by Burke and colleagues suggests:

Around 1 hour: small amounts of carbohydrate (even just rinsing your mouth with a sports drink) can improve performance.
Longer sessions (roughly 1–2.5 hours): about 30–60 g of carbohydrate per hour.
Events over 2.5 hours: up to 90 g per hour may help, using drinks or gels that mix different sugars.

Sports drinks are a convenient way to get both fluid and carbohydrate at the same time. You can also use water plus gels, bars or bananas. Check the label: the carbohydrate per 100 ml times the amount you drink per hour tells you whether you're in the range.

Heavy sweating and heat

If you sweat a lot, exercise for a long time in the heat, or see white salt marks on your clothes after training, you lose more sodium than average. Sodium in a drink helps you replace it and keeps you wanting to drink. Our article on electrolytes helps you work out whether that's you, and weighing yourself before and after a session shows how much fluid you actually lose.

Tournaments and back-to-back sessions

Football tournaments, tennis matches spread over a day or two training sessions on the same day leave little time to refuel with food. A sports drink between games is a practical way to top up fluid, sodium and carbohydrate at once.

The sugar catch

Outside of long, hard exercise, sports drinks are just another sugary drink. The CDC lists them alongside soda and fruit drinks as sugar-sweetened beverages, whose frequent consumption is linked to weight gain, type 2 diabetes, heart disease and tooth decay.

Harvard's Nutrition Source puts a popular sports drink at about 21 g of sugar per serving, about half of what's in a 12-oz cola, but still added sugar. For comparison, the World Health Organization recommends keeping free sugars below 10% of your daily energy, and ideally below 5%, which is about 25 g a day for an adult. One or two bottles a day "for hydration" can use up that budget on their own.

Sports drinks are also acidic, and sipping sugary, acidic drinks for long periods isn't great for your teeth. Rinsing with water afterwards helps.

What about kids?

Children who are just playing, or who train for an hour or less, almost never need sports drinks. Harvard's summary notes that they may help children exercising vigorously for more than 60 minutes, under adult supervision, but that for routine activity water and normal meals are the priority.

Zero-sugar and electrolyte-only drinks

"Zero" sports drinks and electrolyte tablets give you sodium without the sugar. They can make sense if you sweat heavily but don't need fuel, for example during a long hike at an easy pace or a hot day of physical work. They won't help with energy during a long race, because that requires carbohydrate.

Don't confuse sports drinks with oral rehydration solutions (ORS). An ORS has a precise balance of salt and sugar for replacing losses from diarrhea or vomiting. For illness, see what to drink when you're sick.

Don't overdo any drink

More isn't better. Drinking far beyond your thirst and sweat losses during long events can dilute your blood sodium, a dangerous condition called hyponatremia. Sports drinks contain far less sodium than your blood, so they don't fully protect you if you drink too much. If you're running a marathon or doing an ultra, plan your intake rather than drinking at every station. More in can you drink too much water?

A simple rule of thumb

Under 60 minutes, easy to moderate: water.
Over 60 minutes, hard, or in the heat: water plus a sports drink, or water plus food and electrolytes.
Over 2.5 hours: plan carbohydrate (up to 60–90 g per hour) and sodium in advance, and practice it in training.
Not exercising: water. A sports drink is a soft drink here.

Whatever you drink, it helps to know how much you're getting. With Water Tracker on an Apple Watch, you can log a bottle without stopping your workout by turning the Digital Crown, and the amount syncs to your iPhone and, if you like, to Apple Health.

Bottom line

Water covers the vast majority of workouts and everyday hydration. Sports drinks are useful tools for long, hard or hot sessions, where 30–60 g of carbohydrate per hour and extra sodium make a real difference. Outside that, they're sugary drinks with a sporty label. Match the drink to the effort, and when in doubt, reach for water.

This article is general information, not medical advice. If you have a health condition, are pregnant or take medication, ask your doctor how much you should drink.