The science
How much sodium do you actually need? The US Adequate Intake for sodium sits at 1,500mg a day for adults, according to the National Academies’ dietary reference intake report. That number assumes you’re at a normal room temperature and not doing anything strenuous. The same report says people in the heat or doing intense exercise likely need more, but stops short of giving a single number, because sweat rates vary so much from person to person. Two people doing the identical hour of exercise can lose very different amounts of sodium through sweat (NIH/NCBI, National Academies DRI report).
So what
That 1,500mg baseline was built for someone sitting at a desk in an air-conditioned office, not someone doing a hot commute, a warehouse shift, or training for anything. Sweat isn’t just water, it carries salt out with it, and how salty your particular sweat is doesn’t show up on any supplement label. There’s no universal correct number here. A desk job and a landscaping job in July aren’t the same starting point, even for two people the same size. It’s also why sports drinks built for elite athletes look nothing like what a normal day needs. Most of us aren’t running marathons, we’re just trying not to run a deficit by 3pm.
Bottom line
There’s no single answer to how much sodium you actually need, but most people aren’t chronically low sitting at a desk. If you’re properly sweating, whether that’s an actual workout or just a stinking hot day outside, your real number is higher than the office baseline. The honest approach is matching your intake to what you’re actually losing that day, not chasing a fixed number from a guideline or a product label.
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