How much sodium should I take per hour during exercise?

Most endurance athletes need between 500 and 1,000 mg of sodium per hour during prolonged exercise, but the right amount depends on your sweat rate, sweat sodium concentration, and conditions. Heavy sweaters in hot weather can lose 1,500 mg or more per hour, while light sweaters in cool conditions may need far less. Start with 500 mg per hour for efforts lasting more than 90 minutes, then adjust based on thirst, cramping, and how you feel at the finish. Heat and humidity push the number up; cool conditions bring it down. A sweat test gives you a precise target.