While caffeine has historically been a go-to for many—it works and is cheap—a number of preworkout products contain nitric oxide precursors that can provide more than just a boost of energy. Nitric oxide is a molecule that the body produces to help its 50 trillion cells communicate with each other by transmitting signals throughout.
The most common way to increase nitric oxide is through exercise. When you exercise, your muscles need more oxygen than is supplied by the blood. As the heart pumps with more pressure, the lining in your arteries releases nitric oxide into the blood which, in turn, relaxes and widens the vessel wall, enabling for more blood to pass though.
According to the United States National Library of Medicine, “It has been suggested that an increase in NO production may enhance oxygen and nutrient delivery to active muscles, thus improving tolerance to physical exercise and recovery mechanisms.” Interested? Try a preworkout that contains NO precursors like beet-juice extract.