Green Tea may Utilize Fat to Increase Endurance
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Green Tea may Utilize Fat to
Increase Endurance
As recommended as a part
of Dr. Nicholas Perricone's Weight-loss Diet
A report published online on November 24 2004 in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology (http://ajpregu.physiology.org/) revealed that a green tea extract (GTE) improved endurance exercise performance by stimulating fatty acid utilization when given to laboratory animals. Scientists from Tochigi, Japan gave 8 week old mice diets containing a 0.2 percent green tea extract, a 0.5 percent extract, or an unenhanced control diet for 10 weeks. The amount of caffeine that naturally occurs in green tea extract was reduced to control for the possibility of caffeine-induced effects. Half of the control animals and all of the mice who received green tea extract were exercised in a pool twice per week during the course of the study. A second experiment used diets supplemented with low and high doses of EGCG, a polyphenol contained in green tea that has been associated with many benefits.
The research team found that endurance, as measured periodically by how long the mice could swim before exhaustion, was improved by 8 percent by the end of the study in the mice who received the 0.2 percent GTE diets and up to 24 percent in the mice who received the 0.5 percent diets compared to the exercised mice who did not receive the extract. The improvement in endurance was accompanied by a higher rate of fat oxidation, which increased with the higher dose of green tea extract.
While the mice that received EGCG in the second experiment also showed improved endurance compared to the control mice, the effect was not as great as that elicited by green tea extract, showing that other components of green tea may combine to produce the effect.
The polyphenols found in green tea known as catechins have been recently shown to help counteract weight gain resulting from diets high in fat by virtue of their ability to activate the break down of fats in the liver. The authors write, "Overall, observations so far suggest that thermogenesis and fat oxidation are stimulated by the intake of catechins."
Lead author Takatoshi Murase estimated that “an athlete weighing 75 kilograms (165 pounds) would have to drink about four cups (0.8 liter) of green tea daily to match the effect in our experiments.” He added, "One of our important findings was that a single high-dose of GTE or its active ingredients didn't affect performance. So it's the long-term ingestion of GTE that is beneficial."
The authors conclude that, “Although the clinical efficacy of GTE has not yet been confirmed in human studies, our results suggest that GTE may be a useful tool for improving endurance capacity.”
