Do you need sports or electrolyte drinks when you exercise?

Short answer

No, not for workouts under an hour. The sugar gives only a small boost, and salt during exercise did not prevent low blood sodium. For endurance sessions over an hour, and for refilling after heavy sweating, they beat water.

Do you need sports or electrolyte drinks when you exercise?
'Sweat → electrolyte shortage → sports drink is a must' — does this formula hold?
A common claim: when you exercise, sports or electrolyte drinks beat water. A sports drink is water with added sugar and salt. We checked when the sugar and the salt each actually help.
Sugar improved long efforts
The longer the exercise, the bigger the effect
A 2024 analysis pooling 136 studies of eating sugar during exercise found it improved endurance performance, and the effect grew with exercise time. Another analysis pooling 96 studies also found the effect got bigger as exercise stretched from 1 hour to 4 hours.
Under an hour, the boost is small
Just rinsing your mouth had an effect
A review of 61 studies with 679 people concluded that in exercise of about 1 hour, sugar works not as muscle fuel but through taste sensors in the mouth that act on the brain. So the type and amount of sugar did not matter. A 2025 analysis pooling 33 studies of people exercising after a meal found the mouth-rinse effect was small.
Salt did not prevent low blood sodium
The cause was drinking too much
Of 488 marathon runners, 13% finished with blood sodium that was too low. The causes were drinking so much that they gained weight and finishing times over 4 hours; what they drank made no difference. In 174 runners in an 80 km ultramarathon, salt supplements also did not prevent low sodium.
What about body water during exercise?
Not much different from water
An analysis pooling 28 studies found that the water in your blood dropped 7.5% during exercise with plain water and 8.7% with a standard-strength sports drink. The best was a drink with diluted sugar and salt, but it beat water by just 1.1%.
After heavy sweating, it was different
Drinks with salt stayed in the body longer
26 people exercised for 90 minutes without drinking, losing 2.6% of their body weight in sweat, then drank the same amount back. 3.5 hours later, the share kept in the body was 58.1% for water, 73.9% for a sports drink and 76.9% for an electrolyte drink. When 72 people drank 1 L without exercising, a sports drink was no different from water.
Bottom line: you don't need them for workouts under 1 hour
Use them for long sessions and after heavy sweating
Under 1 hour, the sugar gives a small boost, and salt during exercise did nothing for body water or for preventing low sodium. They earn their place in endurance sessions over an hour and after heavy sweating. A 500 ml sports drink with 6% sugar holds 30 g of sugar, or 120 kcal.