Certain neurotransmitters, including acetylcholine, catecholamines, and serotonin, are formed from dietary constituents such as choline, tyrosine, and tryptophan. Changing the consumption of choline can alter the synthesis and release of its respective neurotransmitter product acetylcholine.1 Consumption of supplemental choline can also increase the release of acetylcholine from nerve endings, including those that cause skeletal muscle to contract.2-5 Choline is also incorporated into cell membranes4 that can serve as an alternative choline source for acetylcholine synthesis when there is a deficiency in circulating choline.
It has been shown that increasing the concentration of choline in skeletal5 and cardiac6 muscle increases acetylcholine release.7 My colleagues and I,8 like others,9,10 demonstrated a significant reduction in plasma choline levels following exercise. The reduction in plasma choline levels associated with strenuous exercise (e.g., long distance running or extended swimming) may reduce acetylcholine content, and thus its release, and could thereby affect endurance and performance. We hypothesized that replacement of choline lost during exercise or prevention of that loss could influence neuronal release of acetylcholine and, subsequently, affect measures of athletic performance and fatigue.
The running and swimming exercise paradigms used in a series of experiments
produced similar depletions in plasma choline levels following that particular
exercise.9,10 Running 20 miles or swimming for 2 hours led to a significant fall
in plasma choline levels (40-5O percent). Spector et. al.,11 failed to show a fall
in plasma choline levels after either a brief (approximately 2 minutes
duration), but highly intensive and a longer (approximately 73 minutes duration) submaximal exercise on a stationary bicycle. Apparently, the duration and type of exercise are important determinants of whether plasma choline levels will fall postexercise.
Providing 2 g of free choline prior to exercise prevented a fall in choline levels (25-40 percent) and raised choline levels above baseline values for up to 2 hours postexercise. The bitartrate or citrate sale forms of choline were equally effective. Randomized placebo-controlled crossover studies found improvements in running times and a timed, swim test and suggested that performance in these activities is sensitive to changes in choline levels. In one study, long-distance runners improved running times by an average of S minutes over a 20-mile course when compared with those taking a placebo. In a second study, a higher percentage of swimmers who took choline prior to their swim experienced an improved performance on a timed swim test than when they consumed a placebo.
Findings of degree of fatigue and vigor levels were consistent across all postexercise paradigms. The level of fatigue was lower and the level of vigor was increased in long-distance running, swimming, and a 2-hour basketball workout. It is interesting to note that in two multiple-dosing studies, when choline was given daily for S-7 days, pre-exercise fatigue was also reduced. This
finding suggests that daily administration of choline during strenuous daily exercise periods may be of benefit prior to beginning another bout of exercise.
The data suggest that choline supplementation prior to strenuous exercise may improve performance in certain athletic paradigms as well as reduce fatigue and increase vigor.
References
1. Wurtman RJ. Effects of dietary amino acids, carbohydrates and choline neurotransmitter synthesis. Mt Sinai J Med 1988;55(1):75-86.
2. Wurtman RJ, Hefti F. Melamed E. Precursor control of neurotransmitter synthesis. Pharmacol Rev 1981 ;32(4):315-35.
3. Maire, J-C, Wurtman RJ. Effects of electrical stimulation and choline availability on release and contents of acetylcholine and choline in superfused slices from rat striatum. J Physiol Paris 1985;80:189-95.
4. Blusztajn JK, Wurtman RJ. Choline and cholinergic neurons. Science 1983;221:614-20.
5. Bierkamper GG, Goldberg AM. Release of acetylcholine from the vascular perfused rat phrenic nerve hemidiaphragm. Brain Res 1980;202:234-7.
6. Dieterich HA, Lindmar R. Loffelholz K. The role of choline in the release of acetylcholine in isolated hearts. Arch Pharmacol 1978;301 :207-15.
7. Linden DC, Newton MW, Grinnell AD, Jenden DJ. Rapid decline in acetylcholine release and content of rat extensor digitorum longus muscle after denervation. Exp Neurol 1983;81:613-26.
8. Sandage BW, Sabounjian LA, White R. Wurtman RJ. Choline citrate may enhance athletic performance. Physiologist 1992;35:236a.
9. Von Allworden HN, Horn S. Kahl J. Feldheim W. The influence of lecithin on plasma choline concentrations in biathletes and adolescent runners during exercise. Eur J Appl Physiol 1983;67:87-91.
10. Conlay LA, Wurtman RJ, Blusztajn JK, Covielia IJ, Maher TJ, Evoniuk GE. Decreased plasma choline concentrations in marathon runners (letter). NEM 1986;175:892.
11. Spector SA, Jackman MR, Sabounjian LA, Sakas C, Landers DM, Willis VVT. Effect of choline supplementation on fatigue in trained cyclists. Med Sci Sports Exerc 1995;27(5):669-73.
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