Trendy Fitness Elixir: Beetroot Juice

The Well blog of the New York Times takes note of two popular drinks among Olympic athletes this year—beetroot juice and tart cherry juice. While scientific studies haven't fully backed up their claims, modern athletes seem convinced they provide a natural boost. A few details:

• Beetroot juice: The best guess is that it improves the flow of blood and oxygen, though it seems better suited to aid in short, strenuous sports. "In other words, the juice might help an 800-meter runner but perhaps not a marathoner," writes Gretchen Reynolds. Weekend warriors who want to experiment might try drinking a half-liter a day for about a week before a race or sporting event.

• Tart cherry juice: This probably won't enhance performance itself, but it might speed up recovery afterward. Muscles don't ache as much. One doctor in the story plays the rough-and-tumble sport of Gaelic football, and he swears by it. “My teammates are all at least 20 years younger than me. I would attribute the ability to maintain the fitness required to play in part to the tart cherry juice.” In studies, volunteers typically drink an 8- or 12-ounce bottle per day.

(More beetroot juice stories.)