EFFECTS OF MODE AND CARBOHYDRATE ON THE GRANULOCYTE AND MONOCYTE RESPONSE TO INTENSIVE, PROLONGED EXERCISE

The influence of exercise mode and 6% carbohydrate (C) vs. placebo (P) beverage ingestion on granulocyte and monocyte phagocytosis and oxida tive burst activity (GMPOB) after prolonged and intensive exertion was measured in 10 triathletes. The triathletes acted as their own contro ls and ran or cycled for 2.5 h at similar to 75% maximal O-2 uptake, i ngesting C or P (4 total sessions, random order, with beverages admini stered in double-blind fashion). During the 2.5-h exercise bouts, C or P (4 ml/kg) was ingested every 15 min. Five blood samples were collec ted (15 min before exercise, immediately after exercise, and 1.5, 3, a nd 6 h after exercise). The pattern of change over time for GMPOB was significantly different between C and P conditions (P less than or equ al to 0.05), with postexercise values lower during the C trials. Littl e difference was measured between running and cycling modes. C relativ e to P ingestion (but not exercise mode) was associated with higher pl asma levels of glucose and insulin, lower plasma levels of cortisol an d growth hormone, and lower blood neutrophil and monocyte cell counts. These data indicate that C vs. P ingestion is associated with higher plasma glucose levels, an attenuated cortisol response, and lower GMPO B.