A new study shows that eating wild blueberries, which are rich in bioactive compounds called anthocyanins, may improve athletic performance. After young men consumed freeze-dried wild blueberries for two weeks, their fat oxidation rates during exercise increased by more than 43 percent.

During exercise, fats and carbohydrates undergo oxidation, providing fuel for contracting muscles. At lower exercise intensity, the body relies primarily on fat oxidation; at higher intensity, the body shifts more toward carbohydrate oxidation. During endurance training, the body’s carbohydrate stores can deplete, causing fatigue and impairing athletic performance.

The study involved 11 healthy, aerobically fit men. The men ate 25 grams of freeze-dried wild blueberry powder (roughly equivalent to a cup of fresh blueberries and providing 325 grams of anthocyanins) every day for two weeks. Before and after the intervention, researchers measured men’s fat utilization at 65 percent of their peak oxygen consumption while exercising.

They found that the men’s fat oxidation increased by 19.7 percent after exercising for 20 minutes, 43.2 percent after 30 minutes, and 31.1 percent after 40 minutes. Conversely, their carbohydrate oxidation decreased by 10.1 percent after 20 minutes, 19.2 percent after 30, and 14.8 percent after 40. The men’s lactate levels were lower, too, likely due to improved blood flow.

Anthocyanins are polyphenolic compounds that exert antioxidant, anti-inflammatory, and cardioprotective effects, among others. It’s noteworthy that freeze-drying blueberries induces considerable anthocyanin losses. Eating fresh blueberries may provide even greater benefits to athletic performance.

The findings from this small study suggest that consuming anthocyanin-rich blueberries promotes fat oxidation, thereby enhancing athletic performance. Further studies in larger populations are needed to confirm these effects.

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