What Popeye Should Be Pushing: Protein

Popeye was wrong: You won't be strong to the finish if you eat your spinach. You've got to eat protein to build and maintain muscle mass.

It also makes a difference what kind of protein and what time you eat it. Metabolism researchers at the University of Texas Medical Branch (UTMB) in Galveston are working with NASA and the National Institute of Aging to figure out how to prevent the muscle loss that naturally occurs as people age or travel in space. Their findings suggest you should eat protein an hour or so before you exercise to keep and increase muscle mass.

The reasoning? Your body is more likely to convert protein to muscle if it's circulating in your system before rather than after physical activity. "Exercise seems to help you grab more of the amino acids out of the blood," says Douglas Paddon-Jones, an assistant professor at UTMB, referring to the molecules that are the building blocks of protein.

Don't eat more than 3 oz. of protein at a time: Your body can utilize only so much. The rest is excreted as waste or, worse, stored as fat. The best kind of protein contains the amino acid luceine. Food sources include meat, beans, nuts, and brown rice. "Luceine appears to further stimulate uptake for muscle creation," says Paddon-Jones. And there's only a trace of it in spinach.

By Kate Murphy

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