Nitrate supplements help increase endurance in athletes

A new study has demonstrated that intake of nitrate, a nitric oxide metabolite, can help in increasing the athletic performance.

The study conducted by Federation of American Societies for Experimental Biology 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 .

Andrew Murray, Ph.D., a researcher involved in the work from the Department of Physiology, Development and Neuroscience at the University of Cambridge in Cambridge, United Kingdom, said that their research sheds new light on how oxygen delivery to bodily tissues is controlled to support mammalian life, and what role the kidneys and the liver play in achieving this.

Scientists 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 via diet and drinking water was carefully monitored. Hypoxia is known to elevate hemoglobin levels, but nitrate supplementation at a moderate dose largely suppressed this effect.

It was also observed that nitrate also lowered hemoglobin levels in normoxic animals. The researchers found that at higher doses of nitrate, hemoglobin levels began to rise again. Researchers investigated 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, the kidney became less well supplied with oxygen and at higher doses of nitrate it expressed more erythropoietin, reversing the effect.

The study is published in issue of The FASEB Journal.