Recent quotes:

Mouthwash use could inhibit benefits of exercise -- ScienceDaily

"Previous research has suggested that nitric oxide was not involved in this post-exercise response -- and only involved during exercise -- but the new study challenges these views. "It's all to do with nitric oxide degrading into a compound called nitrate, which for years was thought to have no function in the body. But research over the last decade has shown that nitrate can be absorbed in the salivary glands and excreted with saliva in the mouth. "Some species of bacteria in the mouth can use nitrate and convert into nitrite -- a very important molecule that can enhance the production of nitric oxide in the body. And when nitrite in saliva is swallowed, part of this molecule is rapidly absorbed into the circulation and reduced back to nitric oxide. This helps to maintain a widening of blood vessels which leads to a sustained lowering of blood pressure after exercise. "We wanted to see whether blocking nitrate's ability to convert into nitrite by inhibiting oral bacteria would have any effect on post-exercise hypotension."