Salt has a serious PR problem. Salt has been linked with a rise in cases of hypertension, or high blood pressure, in the population at large. Because hypertension is a huge risk factor in all manner of nasty cardiovascular diseases, salt has, by association, taken a great deal of flak for its alleged contribution to this growing issue.
When taken at face value, there’s an appealingly simple reason why this association between salt intake and hypertension has been drawn. It boils down to the fact that as you consume more and more salt, your body tends to retain more and more fluid in the blood to maintain acceptable blood sodium concentrations. This has the effect of expanding total blood volume and therefore acutely increasing blood pressure, i.e. elevating BP in the short term.
As an aside, this is precisely why we recommend using a saltier drink in the immediate build-up to hot or long races—so that you start with increased blood volume before a period of heavy sweating.
If we can accept that consuming too little sodium is as problematic as consuming too much for health and blood pressure, the conversation around necessary salt intake for athletes starts to get quite interesting.
The bottom line on sodium intake for athletes (or anyone who sweats a lot during the course of their day) is that you should strive to be roughly in-line with your individual sodium losses as a minimum. To use an analogy from the field of Game Theory, sodium consumption should ideally be a zero-sum gain. Intake should essentially cancel out output and therefore, in theory, the effect on overall sodium balance (and as a result, blood pressure and other homeostatic measurements) should be net-zeroANDY BLOW