According to study author Joseph O'Kroy, the nasal strips do improve air flow through the nose. You put the things on your nose and they definitely reduce the resistance to air flow going through the nose. When you breathe through your nose it definitely feels easier. And it is. But O'Kroy says if you understand the mechanics of air flow during exercise, the fact that your nasal passages are freer is superfluous.
Most people breathe through their mouths when they exercise.
But some air does enter through your nose. The thing is, the limitation to getting air into and out of your lungs is in the lungs, not in the nose or the mouth. In the study, which appears in a recent issue of Medicine and Science in Sports and Exercise , O'Kroy exercised 15 colleges students of varying athletic levels to the point of fatigue on exercise bikes under three different conditions. Randomly varying the order of the tests, O'Kroy had them exercise with nasal strips, with placebo strips that did not have the piece of plastic to open the nasal passages and with nasal clips that blocked off all air. And he found no difference in oxygen uptake or maximal work rate.