Telling athletes to drink as much as they can during long workouts might actually be causing more cases of dangerous low sodium, not preventing them.

If you're doing long workouts like marathons, drinking when you're thirsty is safer than chugging water all the time — it helps avoid a dangerous low-sodium condition.

If endurance runners drink too much during long races, it can dilute their blood and cause dangerous low sodium levels — not just from losing salt, but from drinking too much. Cutting back on fluids in events over 4 hours could prevent this problem.

Drinking too much fluid during long workouts can actually be dangerous — it can lead to a serious condition called low blood salt (hyponatremia), especially if you're gaining weight during a race because you're taking in more fluid than you're losing.

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.

Even when rugby players drank way more than they sweated out during workouts, their blood sodium levels stayed normal—no cases of dangerous low sodium were seen.