The authors examined the effect of strenuous exercise on the serum
lithium levels of four healthy, conditioned athletes who were stabilized on
lithium carbonate for 7 days and who ran a 20-km race under hot, humid
conditions. The subjects became substantially dehydrated during the race,
and their serum lithium levels decreased, suggesting that sweat lithium
loss may be substantial. (The sweat-to- serum ratio for lithium exceeded
that for sodium by a factor of 4.) The authors conclude that contrary to
widely held belief, heavy sweating may not increase the risk of lithium
intoxication.Abstract Teaser