The influence of prior activity upon inspiratory muscle strength in rowers and non-rowers

The aim of this study was to investigate whether a 'warm-up' phenomenon in the strength of the inspiratory muscles exists, and, under this assumption, whether whole body warm-up protocols or a specific respiratory warm-up is more effective in this respect. Eleven club level rowers performed a rowing warm-up, and twelve university students performed a general cycling warm-up, Both groups also performed a specific respiratory warm-up, Inspiratory muscle strength (Mueller manoeuvre) and lung function (flow-volume loops) were measured before and after the three conditions, Isokinetic strength during knee extension was measured before and after the rowing warm-up. The two whole body warm-up protocols had no effect on inspiratory muscle strength or any lung function parameter despite the significant (3.8 +/- SD 1.4%; p < 0.05) increase in peak torque that the rowing warm-up elicited. The respiratory warm-up induced a significant increase in inspiratory mouth pressure (8.5 +/- 1.8%; p < 0.0001) but not in any other lung function parameter, Following the rowing incremental test to exhaustion, maximum inspiratory pressure decreased by 7.0 +/- 2.0%, which is an indication of respiratory muscle fatigue, These data suggest that the inspiratory muscle strength can be enhanced with preliminary activity, a phenomenon similar to the one known to exist for other skeletal muscles. In addition, a specific respiratory warm-up is more effective in this respect than whole body protocols.