Taking sodium supplements during a long bike ride in cool weather doesn’t really change your body’s sodium levels if you're already drinking fluids whenever you feel like it.

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.

Taking 700 mg of sodium every hour during a long bike ride in cool weather doesn’t make well-trained cyclists finish faster — they perform about the same as those taking a fake pill.

Taking sodium supplements while cycling for 3 hours in cool weather doesn’t stop your blood sodium from dropping slightly — and it’s no different than taking a fake pill. Nobody in either group had dangerously low sodium levels.

Taking sodium pills while cycling doesn't seem to make well-trained cyclists faster during a 72 km ride in cool weather — they finish just as quickly with or without it.

Endurance cyclists who take in 700 mg of sodium per hour during a 3-hour ride in cool weather tend to drink about 160 mL more fluid each hour than those who don’t — probably because the salt affects how thirsty they feel.