I think you should ask your physician if you need to restrict your sodium when you are cycling and expending more.

If you read at the bottom of this snippet from "Drinking Too Much" from the Ultra Marathon Cycling site, you can see how many of X Brand of electrolyte caps equals the sodium in one liter of sweat.


[SIDEBAR: MEASURING SODIUM]
Labeling on US foods (but not supplements) requires that sodium content be expressed as "mg sodium." However, "mg" are unwieldy for describing blood plasma concentration, so "milliequivalent," or "mEq" is used instead. Milliequivalent is a number, like 'dozen.' Twenty three mg of sodium is equivalent to one mEq of sodium. Normal plasma sodium concentration is 135-145 mEq/liter (or 3105 – 3335 mg/liter!). One teaspoon of table salt contains about 100 mEq sodium, 2400 mg sodium, and 6000 mg sodium chloride. The average daily intake of sodium in the US is 150 mEq, corresponding to about 1.5 teaspoons of table salt. The sodium concentration in sweat varies considerably across individuals, but a reasonable average is 50 mEq/liter. Happily, 50 mEq is about 1000 mg or 1g sodium. Thus, you can easily use "mg" to track your sodium intake. When you get to 1000 mg, you're at about 50 mEq. Among supplements marketed as sodium and/or electrolyte supplements, Succeed® has 15 mEq sodium/capsule, Thermotabs® have 8 mEq sodium/tablet, and Endurolytes® have 2 mEq sodium/capsule. Thus, 3 Succeed®, 6 Thermotabs® or 25 Endurolytes® capsules have the approximate sodium equivalent of an average liter of sweat.