An external nasal dilator (Breathe-Right) is frequently used by athletes with the hope of improving athletic performance. The purpose of this device is theoretically to increase the nasal valve area as well as nasal airflow. The purpose of this study was to evaluate whether the use of an external nasal dilator would impact various parameters related to exercise. These included oxygen consumption (VO,), heart rate, and respiratory rate. In addition, the nasal dilatory effects from the use of the dilator were measured via acoustic rhinometry. This study had two separate phases: 1 ) to measure the extent that the nasal dilator had on nasal valve area using acoustic rhinometry on 53 healthy volunteers. 2) to determine the effect of the nasal dilator versus placebo on submaximal exercise economy. The second study was performed on a group of athletes who were asked to perform two submaximal exercise tests using either a placebo nasal strip without elastic strips or the nasal dilator. In the first study, cross-sectional areas from each side of the nasal cavity were measured and a significant difference in mean cross-section area was observed between the placebo group ( 1.22 cm2) and the device group ( 1.52 cm2). The mean area increase in whites (0.36 em2) was significantly larger than that in blacks (0.20 cm2), but there was no difference seen between men and women. In the exercise protocol, differences were noted both in VO2 and ventilation to be significantly improved in the dilator group at both low intensity and high intensity physiological workloads. The respiratory exchange ratio was not found to be different in either group. Heart rate differences were not noted in the low intensity, but were noted in the high intensity workloads. This is an interesting study evaluating the use of an external nasal dilator on exercise and aerobic capacity. It is somewhat surprising that significant changes are noted, given the predominance of oral airflow at high exercise intensities. VO-, max. which is oxygen utilization at maximal exercise, was not performed. Overall, the study was well done and may show benefit of an external nasal dilator for exercise, particularly at nonmaximal workloads. It was somewhat disappointing that the authors did not include more data. It would have been interesting to see the impact on various specific populations. Since the mean area increased in the control group in whites was significantly greater than in blacks. it would be interesting to see if there would be differences in changes in VO, ventilation, and heart rate lor those groups. In addition, some breakdown of the type of athlete that was used in the study would be beneficial to the reader to determine whether this would be beneficial for them. For example, if there was a high proportion of either anaerobic or aerobic athletes, the application of these findings might be different for different athlete populations.