Salt Supplementation for Exercise and Training?

For some reason, exercise and training seem to attract a fair amount of myth and magic. Is salt supplemenation really needed for aerobic training? Lets find some evidence.

http://www.ajcn.org/cgi/reprint/72/2/564S

http://www.ultrunr.com/noakes.html

I quote;

Other electrolytes and minerals
Potassium is the major intracellular ion and is lost from the body in sweat and urine during exercise. However these losses are small (<1 gm even during very prolonged exercise) and are replaced by the normal daily dietary intake of 2-4 g. There is no evidence that potassium supplementation is required by the physically active.
Magnesium is another intracellular ion that, like potassium, is lost in sweat and urine during exercise. But the losses are trivial. There is no published evidence showing that magnesium deficiency is either common amongst the physically active, or that magnesium supplementation can either increase the intracellular magnesium stores, or enhance performance (15). The balance of evidence indicates that although body iron stores may be marginally reduced in some athletes, especially long distance runners, the incidence of true iron deficiency requiring treatment is no higher in the physically-active than in the sedentary population (16,17). Furthermore, the causes of iron deficiency anaemia in the physically active are not different from the causes of the condition present in sedentary persons. There is no indication for the indiscriminate use of iron supplementation by the physically active.
The intake of calcium especially by adolescent females, whether or not they are physically active, is usually less than the Recommended Daily Allowance (RDA). Hence adolescent female athletes come from a population that is already predisposed to an inadequate calcium intake. Female athletes in activities that favour thinness such as gymnastics, ballet dancing and running, are especially likely to eat kilojoule-restricted and therefore calcium-deficient diets. The chronic ingestion of a low calcium diet is associated with a reduced adult bone mass (18) and greater risk for the development of osteoporosis including the complications of fractures of the hip (19) or, in athletes, stress fractures (20). Hence there is a need to insure that females especially, ingest sufficient calcium throughout life.
There is no published evidence that the dietary requirements for chromium, copper, zinc or phosphate are increased in the physically active or that supplementation with any of these nutrients will improve athletic performance.