If endurance athletes drink a lot during long workouts and also take in sodium, it might help prevent low blood salt levels — but it probably won’t make them perform better just by itself.

You won’t get low sodium symptoms from sweating during long workouts unless you drink way too much water — so replacing sodium isn’t the most important thing to prevent this issue.

If elite cyclists drink as much as they want during a 3-hour ride in cool weather, taking in 700 mg of sodium per hour helps keep their blood fluid levels stable—or even slightly increases them—while skipping it leads to a small drop.

If endurance-trained guys eat less salt for 9 days, their blood sodium drops — even if they drink enough water — especially when they bike in the heat. This suggests long-term salt intake might affect how their body handles hydration in hot weather.

If endurance cyclists drink fluids with sodium during long rides, they pee less and keep more fluid in their bloodstream, which helps prevent dehydration—even though the salt level in their blood stays the same.

Even if endurance runners take a lot of salt pills during long races, drinking too much water — like 10 liters — can still give them a dangerous condition called low blood sodium. Salt alone won’t protect you if you’re chugging way too much water.