The now commonplace wearing of external nasal splints by sportsmen and athletes has never been scientifically evaluated. The present study looks into the effect of both isometric and isotonic exercise on nasal resistance and examines if this is altered by the wearing of an external nasal splint. Twenty subjects who did not suffer from rhinitis were tested. Nasal resistance measurements were recorded using an anterior rhinomanometer before and after exercise, with and without an external nasal splint. Pulse and blood pressure were measured using a Criticare Inc. model 508 physiological monitor before and after exercise. Significant changes were observed in pulse (P < 0.001) and both systolic (P < 0.002) and diastolic (P < 0.001) blood pressure in response to isotonic exercise and pulse (P < 0.0001) and diastolic blood pressure (P < 0.0006) in isometric exercise. Significant differences were seen in nasal resistance when the splint was applied before (P < 0.001) and after exercise in both groups (P < 0.003). No significant difference was observed between the post-isotonic exercise groups with and without the splint (P = 0.167) but significant differences were seen in the isometric group (P < 0.0001). External nasal splints decrease nasal resistance at rest but are of little proven value when performing isotonic exercise however significantly reduce nasal resistance during isometric exercise.