Does Beetroot Improve a Runner's Time?

Sept. 27, 2011 (San Diego) -- Runners and other exercisers hoping to improve their performance might consider a detour to the produce aisle.

Eating beetroot before a workout gave runners a modest edge in speed during a 5K run when they were close to the finish line, new research shows.

The baked beetroot won out over the cranberry relish that served as a comparison, says Margaret Murphy, RD, a Chicago dietitian who conducted the research as a graduate student at St. Louis University.

''With the beetroot, they were 41 seconds faster at the finish," and that could make the difference between a win or not among competitive amateur runners, she says.

The study was presented at the American Dietetic Association's Food & Nutrition Conference & Expo here in San Diego.

Beetroot and Exercise

For exercise performance, "there has been a lot of interest in beetroot juice for the last couple of years," Murphy tells WebMD.  A study from the U.K., for instance, found that exercisers could work out longer if they drank beetroot juice.

Other research has found that beetroot juice can help reduce blood pressure.

Beetroot is rich in substances called nitrates. Nitrates are converted into nitric oxide by the body. The nitric oxide dilates blood vessels. That results in improved oxygen delivery.

"You are going to have more ability to sustain aerobic activity," Murphy says.

Murphy decided to study the whole vegetable rather than the juice.

She assigned 11 men and women, all recreationally fit athletes, to eat the beetroot or the cranberry relish, in random order, once before a 5K run. The tests were done a week apart. The average age of the exercisers was 25.

They each ate 200 grams, about 7 ounces, of beetroot. That amount has about 500 milligrams of nitrates.

After the beetroot, exercisers had overall times that were 3% faster compared to their times after eating cranberry relish, and 5% faster during the last mile, she found.

Beetroot Recipe

Beetroots can be found in the produce section of the market. They look a bit like radishes.

The beetroot recipe is simple, Murphy tells WebMD.

• Place about 7 ounces (the amount of one portion in her study) on a baking sheet.
• Bake at 350 degrees for 90 minutes or so.
• Peel off the skin, then put the remaining beetroot in a food processor.
• Add a tablespoon of lemon juice, 1/8 teaspoon of cinnamon, and 1/8 teaspoon of nutmeg. This will make it more palatable.

She gave the men and women the beetroot about 45 minutes before they jogged because they came into the study after fasting. However, for those who want to try it, she suggests eating it about two and a half hours before an event.