EFFECT OF LOW-CARBOHYDRATE AND HIGH-CARBOHYDRATE DIETS ON THE PLASMA GLUTAMINE AND CIRCULATING LEUKOCYTE RESPONSES TO EXERCISE

We examined the effects of a low-carbohydrate (CHO) diet on the plasma glutamine and circulating leukocyte responses to prolonged strenuous exercise. Twelve untrained male subjects cycled for 60 min at 70% of m aximal oxygen uptake on two separate occasions, 3 days apart. All subj ects performed the first exercise task after a normal diet; they compl eted the second exercise task after 3 days on either a high-CHO diet ( 75 +/- 8% CHO, n = 6) or a low-CHO diet (7 +/- 4% CHO, n = 6). The low -CHO diet was associated with a larger rise in plasma cortisol during exercise, a greater fall in the plasma glutamine concentration during recovery, and a larger neutrophilia during the postexercise period. Ex ercise on the high-CHO diet did not affect levels of plasma glutamine and circulating leukocytes. We conclude that CHO availability can infl uence the plasma glutamine and circulating leukocyte responses during recovery from intense prolonged exercise.