Potassium losses from sweating

It has been previously demonstrated that considerable quantities of sodiurn and potassium are lost through sweating (11,12). Loss of potassium from skin has been estimated to be of the magnitude of 44% of the total potassium losses. Furthermore, loss of potassium caused by strenuous physical activity in hot climates may cause rhabdomyolysis and myoglobinuria. 

Elimination of Tl is mainly through the gastrointestinal tract but elimination also occurs through the kidneys, saliva, hair, skin, sweat, and breast milk. Relative amounts excreted by each route vary by species. Thallium is likely excreted through intestinal and gastric secretions associated with potassium loss or excretion. Likewise, reabsorption of Tl also occurs, mainly from the colon. The estimated biological half-life of Tl is 10 days but values up to 1 month have been reported (WHO, 1996). 

Generally, a deficiency of potassium sufficient to impair the functioning of the heart does not result from a dietary shortage of the element since many foods are good sources. However, the supply of the mineral in the cells of the heart muscle may be low due to such factors as (1) excessive losses in the digestive tract (as diarrhea and vomiting), in sweat (particularly during hot and humid weather), or in urine (as a result of acidosis, diuretics, and various stress... 

It should be noted that deficiencies of potassium rarely result from dietary lack of the mineral rather, they result from crash diets, diarrhea, diabetic acidosis, vomiting, intense and prolonged sweating, body burns, and heavy urine losses induct by diuretic drugs (also known as "water pills"). 

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