OK, but do nitric oxide supplements actually work?
Honestly, we don't really know. There'
s simply not enough evidence to suggest that they do.
"[The idea is that these supplements] will increase NO, and then because of that, it'll cause vasodilation, and then the downstream effect of vasodilation would be this massive increase in blood flow, which leads to increased exercise performance and enhanced recovery," says Richard Bloomer, Ph.D., dean of the School of Health Studies and The Center for Wellness and Fitness at the University of Memphis. "But most, if not all, of [these purported benefits] have not been supported by available evidence."
In studies that have shown a link between improvements in performance and nitrate levels in the blood, such positive results could simply be a result of extensive training, as exercise itself enhances nitric oxide activity. Plus, dietary nitrate comes from other sources, like vegetables, and most studies don't control for this.
Even if there
are benefits to nitric oxide supplementation, it's unclear whether they would apply to everyone. A
review of 42 studies related to the effects of dietary ingredients linked with nitric oxide and exercise performance
found mixed results: the review concluded that while nitric oxide supplements may "improve tolerance" to aerobic and anaerobic exercise in people who either aren't in shape or are moderately trained, there seems to be no benefit in highly trained people.