How Much Water Does the Galpin Equation Call for?

Andrew Huberman says hydration is a big factor in cognitive function, and people often overlook it. He calls the rule the Galpin equation, after exercise physiologist Andy Galpin, who built it for physical work. Huberman says the same rule works for cognitive work.

Body weight in pounds divided by 30 gives the ounces of water to drink about every 20 minutes while exercising or doing mental work. The volume can mean an extra trip to the bathroom or two. Huberman says that extra trip is worth it.

Dehydration is a subtle but very pernicious creep. The eyes get hard to focus, and the feeling is a want to go to sleep. The hydration factor is real, so drink plenty of fluids, especially when ingesting caffeine, because caffeine is a diuretic.