Green tea may soon show up in locker rooms and doping tests after being found to boost exercise endurance in mice up to 24% while spurring the use of fat as energy.

While the finding is based on green tea extract (GTE) and is difficult to extrapolate to human athletes, Japanese researcher Takatoshi Murase estimates that to match the effects athletes weighing 75 kilograms (165 pounds) would need to drink about four cups of green tea a day—and over several weeks.

“One of our important findings,” says Murase, “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 study was conducted by Murase and colleagues at the Biological Sciences Laboratories of Kao Corp. in Tochigi, Japan—a company that makes green tea beverages and has been investigating the tea’s anti-obesity effects.

The researchers say their findings show that green tea extract can boost exercise capacity and support the hypothesis that stimulating the use of fatty acids can improve endurance.

More here.