What if we told you that one of the most potent, performance-enhancing nutrition supplements is completely natural, cheap and already in your fridge? Nitrate-rich foods, like certain fruits and vegetables (and their juices), possess the power to dilate blood vessels and increase your circulation, which means more oxygen is delivered to the muscles and enhanced endurance and performance.

As a matter of fact, one study in the Journal of the International Society of Sports Nutrition found that CrossFit-trained athletes enhanced their peak power output in an all-out maximum effort cycling test after just six days of nitrate supplementation. Even if you don’t want to go all out, research suggests that adding nitrate-rich foods to your diet may still help exercise performance. A similar study in the International Journal of Sports Physiology and Performance found that drinking nitrate-rich beetroot juice 2-3 hours before exercise increased peak cycling power and pedaling velocity during sub-maximal exercises tests.

Not only will boosting circulation make you stronger and faster, it will also help ward off the number-one killer in the U.S., heart disease. February is American Heart Month, so do your heart a favor and add these nitrate-rich foods to your diet.