Endurance athletes have long sworn by beets and beet juice for a competitive edge. Studies have shown that the root vegetable's rich concentration of dietary nitrates helps promote blood flow and oxygen to the muscles, providing a solid performance boost. Now, researchers from the University of Exeter have learned that these same effects may also keep the exercise-weary brain firing on all cylinders. Supplying the brain with ample oxygen may help you react more quickly and make smarter decisions, say, late into a tennis match or pickup basketball game.
The study looked at 16 male team-sport athletes who were asked to complete two identical rounds of intense intervals on a stationary bike — once after supplementing with two shots of nitrate-rich beet juice per day for seven days and a taking a double-shot 2.5 hours before hopping on the bike, and a second time after following the same regimen but with a placebo juice that had the nitrate taken out. The cycling tests consisted of intermittent sprints and active and passive recovery in order to mimic the constantly shifting workload demands of team sports. During the stints of active recovery, the athletes performed various cognitive tests to gauge their response time and accuracy while fatigued from exercise.
Along with knocking out 3.5 percent more work while sprinting after supplementing with beet juice compared to their post-placebo tests, the men's mental performance also rose. "The participants were able to make the same decisions, only faster, following nitrate-rich beet juice," says lead study author Chris Thompson.
How does beet juice work its mental magic? "With increasing exercise duration and intensity, cognitive performance may suffer," Thompson says. But nitrate-rich beetroot juice may offset that, Thompson says, by providing much-needed oxygen to the areas of the brain responsible for quick decision-making.
Thompson's team used super-concentrated shots of beet juice for the study, and although eating whole beets could also do the trick, Thompson says it's much harder to gauge their actual nitrate content, which can vary greatly depending on where and how the vegetables are grown. "If athletes wish to explore the use of nitrates, it may be more convenient to use a beet juice shot with known concentrations," he says. You can find these readily at health food stores and juice shops.
What's more, Thompson stresses the benefits of dietary nitrates beyond just immediate performance gains. "I encourage a high-nitrate diet of spinach, lettuce, and other green leafy vegetables because of the positive impact on cardiovascular health, such as lowering resting blood pressure and the oxygen cost of exercise."