TY - JOUR
T1 - Failure of caffeine to affect substrate utilization during prolonged running
AU - Casal, David C.
AU - Leon, Arthur S
PY - 1985/2
Y1 - 1985/2
N2 - Nine sub-3-h male marathoners performed three 45-min monitored treadmill runs at approximately 75° of VO2max during a 2-wk period. The men were assigned in a random, double-blind fashion following the control run to receive either 350 ml of decaffeinated coffee or 350 ml of decaffeinated coffee with 400 mg of caffeine added 1 h before the second run with crossover to the other beverage for the third run. Venous blood was analyzed for free fatty acids, triglycerides, glucose, and lactic acid before beverage consumption and before and after each run. Oxygen consumption (VO2max), carbon dioxide production (VCO2), respiratory exchange ratio (R), ventilation (VE), and perceived exertion were measured at 15,30, and 45 min of each run. Of the blood parameters, free fatty acid and lactic acid concentration increased following caffeine ingestion. There was no difference in VO2max, VCO2, or R between the three runs. Perceived exertion showed a significant decrease (P < 0.05) at each time point in caffeine added and decaffeinated compared to control. Triglycerides, glucose, and lactic acid increased similarly in all three runs. In these well-trained marathoners, although plasma free fatty acids were elevated significantly prior to exercise after caffeine ingestion, there was no indirect evidence of altered substrate utilization during subsequent treadmill running.
AB - Nine sub-3-h male marathoners performed three 45-min monitored treadmill runs at approximately 75° of VO2max during a 2-wk period. The men were assigned in a random, double-blind fashion following the control run to receive either 350 ml of decaffeinated coffee or 350 ml of decaffeinated coffee with 400 mg of caffeine added 1 h before the second run with crossover to the other beverage for the third run. Venous blood was analyzed for free fatty acids, triglycerides, glucose, and lactic acid before beverage consumption and before and after each run. Oxygen consumption (VO2max), carbon dioxide production (VCO2), respiratory exchange ratio (R), ventilation (VE), and perceived exertion were measured at 15,30, and 45 min of each run. Of the blood parameters, free fatty acid and lactic acid concentration increased following caffeine ingestion. There was no difference in VO2max, VCO2, or R between the three runs. Perceived exertion showed a significant decrease (P < 0.05) at each time point in caffeine added and decaffeinated compared to control. Triglycerides, glucose, and lactic acid increased similarly in all three runs. In these well-trained marathoners, although plasma free fatty acids were elevated significantly prior to exercise after caffeine ingestion, there was no indirect evidence of altered substrate utilization during subsequent treadmill running.
KW - Caffeine
KW - Glucose oxidation
KW - Lipid oxidation
KW - Marathon runners
KW - Perceived exertion
KW - Respiratory exchange ratio
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U2 - 10.1249/00005768-198502000-00029
DO - 10.1249/00005768-198502000-00029
M3 - Article
C2 - 3982273
AN - SCOPUS:0021949023
SN - 0195-9131
VL - 17
SP - 174
EP - 179
JO - Medicine and science in sports and exercise
JF - Medicine and science in sports and exercise
IS - 1
ER -