Fluid Replacement and Heat Stress, 1993
Pp. 117-126. Washington, D.C.
National Academy Press
James P. Knochel1
It has been established by a number of investigators that potentially serious potassium deficiencies can occur in soldiers under conditions of intense, prolonged training in hot weather. Studies conducted during or after World War II (Conn, 1949; Streeten et al., 1960), and confirmed by others since that time (Gordon and Andrews, 1966; Knochel, 1977a; Knochel et al., 1972; Malhotra et al., 1976; Toor et al., 1967), have shown that men working in the heat for 8 to 12 hours on successive days can secrete up to 12 liters of sweat per day. Although measurements of the potassium concentration in sweat have shown values ranging between 2.5 and 21 mEq/liter (Robinson and Robinson, 1954), the majority of investigators have found that sweat produced under conditions of hard work generally ranges between 8 to 10 mEq/liter (Beller et al., 1975; Cage et al., 1970; Dobson and Abele, 1962; Drinkwater et al., 1982; Emrich et al., 1970; Furman and Beer, 1963; Grand et al., 1967; McConahay et al., 1964; Mor et al., 1985; Nose et al., 1988; Verde et al., 1982). This implies that sweat losses alone could explain the development of potassium deficiency during training in the heat.
James P. Knochel, Presbyterian Hospital, Walnut Hill Lane, Dallas, TX 75231