It has been reported that plasma choline levels decrease following certain types of strenuous exercise. Preliminary findings also suggest that a drop in plasma choline may limit physical performance, while choline supplementation may delay fatigue during prolonged efforts. A double-blind crossover design was used to determine the relationship between plasma choline and performance during and after 4 hr of strenuous exercise. Volunteers (N = 14) received either a placebo or treatment beverage (8.425 g choline citrate) prior to and midway through a 4-hr load carriage treadmill exercise (3% grade at 5.6 km/h × 20 km) carrying a total load of 34.1 kg. Following the treadmill test, run time-to-exhaustion and squat tests were performed, and perceived exertion, plasma choline, glycerophosphocholine, and phosphatidylcholine were measured. Plasma choline levels increased 128% after the run-to-exhaustion with the choline supplemented beverage but remained unchanged with the placebo beverage. No significant effects were seen with choline supplementation on any outcome performance measure. Consequently, soldiers conditioned to carry heavy loads over long distances do not deplete plasma choline as a result of a prolonged exhaustive exercise under a placebo beverage, nor do they benefit from choline supplementation to delay fatigue under the same conditions.
J.P. Warber is chief of the Nutrition Care Division with Womack Army Medical Center, Fort Bragg. NC 28310-5000. At the time of the study, Dr. Warber was the Senior Military Research Dietitian with the Military Nutrition and Biochemistry Division. W.J. Tharion. CP. Kemnitz, and H.R. Lieberman are with the Military Nutrition and Biochemistry Division of the U.S. Army Research Institute of Environmental Medicine. Natick, MA 01760-5007. J.F. Patton and R.P. Mello are with the Military Performance Division of the U.S. Army Research Institute of Environmental Medicine. S.H. Zeisel is with the Department of Nutrition at the University of North Carolina, Chapel Hill, NC 27599-7400.