Q: I have heard that drinking beer after a marathon has a scientific benefit.
A: There are reports circulating that in the 1970s, Jim Fixx advocated beer drinking among runners. Other runners also claim there is a benefit to alcohol consumption after a marathon. If there is a benefit of alcohol consumption, it is probably psychological and not physiological.
Alcohol and Dehydration
Dehydration is known to cause a decrease in live running performance. Studies show that beer actually causes dehydration. Alcohol inhibits release of the hormone vasopressin and delays the sensation of thirst. Vasopressin is an antidiuretic hormone which causes the kidneys to conserve water, but not salt. Vasopressin is normally released by the body when the body is in a state of dehydration.Vasopressin also moderately increases vasoconstriction of blood vessels, increases peripheral vascular resistance and increases blood pressure.
Alcohol and Inhibition of Fat Metabolism
Scientists at the Indiana Alcohol Research Center reported in 2006 that alcohol ingestion inhibits metabolism of fat. The scientists reported that ethanol was shown to inhibit adenosine monophosphate-dependent protein kinase (AMPK), which (without alcohol inhibition) controls fatty acid metabolism by inhibiting acetyl-coenzyme A carboxylase, reducing malonyl-coenzyme A, and thereby permitting fatty acid transport into and oxidation in the mitochondrion.
In other words, when alcohol inhibits AMPK, then acetyl-coenzyme A carboxylase is not inhibited and intracellular malonyl-coenzyme A levels increase inside liver cells. The increase in malonyl-coenzyme A levels is related to decreased activity of the liver enzyme carnitine pamitoyltransferase I and decreased rate of fatty acid oxidation.
Bodybuilding.com reports (with no references) a study of eight men were given two drinks of vodka and lemonade separated by 30 minutes. Each drink contained just under 90 calories. Fat metabolism was measured before and after consumption of the drink.
For several hours after drinking the vodka, whole body lipid oxidation (a measure of how much fat your body is burning) dropped by 73%.
Effect of Alcohol on Glycogen Storage After Exercise
A study of the vastus medialis muscles of cyclists immediately after a glycogen-depleting workout showed that a direct effect of alcohol and reduced glycogen storage was unclear. Researchers reported a trend to reduced glycogen storage in eight hours, but not in 24 hours. The researchers concluded that alcohol consumption’s effect on glycogen storage was more indirect (rather than by direct biochemical proof) by displacing other carbohydrate intake with optimal recovery nutrition practices. Fuel from alcohol is not converted into glycogen.
Another study found that acutely impaired glycogen resynthesis in the tibialis anterior and the red muscle type of gastrocnemius muscle of rats, but it did not impair the resynthesis of glycogen to the white muscle type gastrocnemius.
Another study to note because of the irony of high concentration of glycogen in the muscle tissue of chronic alcoholics: Researchers discovered the inhibition of glycogen phosphorylase kinase at pH 6.8 at a very low concentration of ethanol. There was no effect of acetaldehyde on this enzyme. Neither ethanol not acetaldehyde has been shown to have any effect on glycogen synthase, glycogen phosphorylase, protein phosphatase or independent and cAMP-dependent protein kinases. This inhibition could explain the high concentration of glycogen in the muscle tissue of chronic alcoholics that is found when ethanol is present in skeletal muscle.
Sports nutritionist Dr. Liz Applegate emphasizes the research that alcohol actually interferes with the recovery process by hampering glycogen re-synthesis in the muscle and liver.
Alcohol Anyway …
However, many runners claim that a beer after a long run invigorates and it is still a favorite along finish lines. Of course beer AFTER a run isn’t going to affect the actual race and would probably only be a factor if a runner has another race to run within 24 hours.
Some road races in America today are based on alcohol parties. The Falmouth Road Race in Massachussetts is held every August on Cape Cod and utilizes an odd 7-mile distance because that is the distance between two bars, the Captain Kidd in Woods Hole and the Brothers Four in Falmouth. The race was founded by Tommy Leonard, a bartender who worked at a bar called Brothers four in Falmouth Heights.
Sources:
Eisenhofer G, Johnson RH. Effects of ethanol ingestion on thirst and fluid consumption in humans. Am J Physiol. 1983 Apr;244(4):R568-72.
Crabb DW, Liangpunsakul S. Alcohol and lipid metabolism.
J Gastroenterol Hepatol. 2006 Oct;21 Suppl 3:S56-60. Review.
Guzman M, Geelen MJ. Short-term inhibition of carnitine palmitoyltransferase I activity in rat hepatocytes incubated with ethanol. Biochem Biophys Res Commun. 1988 Jul 29;154(2):682-7
Guzman M, Castro J, Maquedano A. Ethanol feeding to rats reversibly decreases hepatic carnitine palmitoyltransferase activity and increases enzyme sensitivity to malonyl-CoA.
Biochem Biophys Res Commun. 1987 Dec 16;149(2):443-8
Burke LM, Collier GR, Broad EM, Davis PG, Martin DT, Sanigorski AJ, Hargreaves M.
Effect of alcohol intake on muscle glycogen storage after prolonged exercise. J Appl Physiol. 2003 Sep;95(3):983-90
Peters TJ, Nikolovski S, Raja GK, Palmer TN, Fournier PA. Ethanol acutely impairs glycogen repletion in skeletal muscle following high intensity short duration exercise in the rat. Addict Biol. 1996;1(3):289-95.
Cusso R, Vernet M, Cadefau J, Urbano-Marquez A. Effects of ethanol and acetaldehyde on the enzymes of glycogen metabolism. Alcohol Alcohol. 1989;24(4):291-7.
Keywords:
alcohol muscle glycogen recovery
ethanol muscle glycogen recovery
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