Inspiratory Muscle Fatigue in Male University Rugby Players

Abstract

Rugby Union is a team based invasion game played on a grass field between two teams of 15 players. The game is played over two 40 minute periods and involves a high level of physiological strain. PURPOSE: The aim of this study was to investigate the change in Maximal Inspiratory Pressure (MIP) that occurs in University players as a result of a game of Rugby Union. METHODS: Thirty male Loughborough University rugby union players (Age 20.1 + 0.82 years, Stature 1.84 + 0.07m, Mass 92.4 + 10.1kg from the first and second team squads played a fully officiated 80 minute 'training' game against each other. Maximal Inspiratory Pressure (MIP) as measured at the mouth (Micro medical-RPM) was taken post warm up but before the game (PRE), during the half time interval (HALF) and again post game (POST). Players were described as either forwards (FOR) or backs (BACK) depending upon their playing position. All players had previously undergone a familiarisation process with the instrumentation, the testing process and the MIP measurements themselves. RESULTS: A repeated measures ANOVA (SPSSv15.0.1) showed there to be significant variability within the data set (p>0.05). Post hoc pairwise comparisons showed the difference was for all cases (PRE v HALF, PRE v POST and HALF v POST). This difference remained when the group was split for position played (FOR PRE v FOR POST and BACKS PRE v BACKS POST) however, there were no differences present when the playing positions were compared against each other (PRE FOR v PRE BACKS and POST FOR v POST BACKS. Bland and Altman 95% limits of agreement were also calculated for the player position comparison (16.1 + 68.3 mmH2O) as well as the PRE-Post comparison (-22.4 + 40.1 mmH2O). MIP scores were not significantly correlated against Body Mass (r2 0.0004) or Stature ( r2 0.0003). CONCLUSIONS: Rugby players show a reduction in MIP post-game which may be due to the physiological strain imposed by the demands of the game. There is a large degree of variability in MIP between individuals regardless of their playing position or physical dimensions. In order to ascertain whether this reduction in MIP can be attenuated this study should be repeated following a period of Inspiratory muscle training.