Thermoregulation, plasma catecholamine and metabolite levels during submaximal work in individuals susceptible to malignant hyperpyrexia.

Measurements of body temperature, respiratory gas exchange, sweat evaporation rate and circulating levels of catecholamines, lactate, pyruvate, free fatty acids and glucose were made in seven patients susceptible to malignant hyperpyrexia (MHS) and in seven control subjects during 2 h of treadmill walking at 40% of maximum oxygen consumption. These studies took place in an ambient temperature of 22 degrees C. The MHS patients displayed the same thermoregulatory, plasma catecholamine and metabolic responses as the control subjects. The results of the present study suggest that non-competitive, low-intensity, steady-state exercise need not be contraindicated for MHS patients.