Intake of nitrate, a nitric oxide metabolite, can help in increasing the athletic performance, demonstrated a new study conducted by Federation of American Societies for Experimental Biology. The study explained how some of these supplements may work and why they may increase performance as they decrease the viscosity of blood, aiding in blood flow, while at the same time ensuring that tissue oxygen requirements are not compromised .
Researchers investigated the effects of nitrate supplementation on hemoglobin in four groups of rats, which were housed in either normoxic or hypoxic (low oxygen) conditions and supplemented with sodium nitrate or sodium chloride (ordinary table salt) as a control. Intake of nitrate from diet and drinking water was carefully monitored. Hypoxia is known to elevate hemoglobin levels in the blood, but nitrate supplementation at a moderate dose largely suppressed this effect.
The researchers found that nitrate also lowered hemoglobin levels in normoxic mice. It was also observed that at higher doses of nitrate, hemoglobin levels began to rise again. Researchers studied the mechanisms underlying these effects and found that the suppression of hemoglobin was due to nitrate enhancing liver oxygenation and suppressing its expression of the hormone, erythropoietin. Conversely, as hemoglobin levels fell down, the kidney became less well supplied with oxygen and at higher doses of nitrate it expressed more erythropoietin, reversing the effect.