Physiologic and metabolic response to progressive and prolonged exercise in amyotrophic lateral sclerosis

Physical work capacity in 35 ALS patients and 6 untrained controls was evaluated during proqessive bicycle ergometery. In the ALS patients, maximum oxygen consumption (VO₂max) and work capacity (Wmax) drop in relation to the decrease in ALS functional score. However, the oxygen cost (ml O₂/ kpm) of submaximal exercise was significantly increased. Prolonged submaximal exercise tests in six ALS patients and six matched untrained controls indicated that the exercise-induced increase in plasma free fatty acids, beta-hydroxybuty-rate, esterified carnitine, and muscle esterified carnitine was significantly retarded in ALS patients.