Differentiating the Influence of Inspiratory and Expiratory Muscle Training Upon Rowing Performance in Club-Level Oarsmen

Respiratory muscle training (RMT) has been shown to yield improvements in exercise performance in healthy young people. In these studies, two different forms of respiratory training have been employed, with similar outcomes; 1) voluntary isocapnic hyperpnoea (VIH); 2) pressure threshold inspiratory muscle training (IMT). The former is an endurance training approach that involves both the inspiratory and expiratory muscles, the latter employs resistance training principles and is confined to the inspiratory muscles. It remains unclear whether the addition of expiratory muscle training (EMT), as occurs during VIH, provides any additional benefit to IMT alone.
PURPOSE: To investigate the effects of 4-wk of inspiratory muscle training (IMT) or expiratory muscle training (EMT), as well as the effect of a subsequent 6-wk period of concurrent IMT/EMT upon rowing performance in club-level oarsmen.
METHODS: Informed, written consent was obtained from 17 male rowers who were allocated randomly to either an IMT (n=10) or EMT (n=7) group for the first 4-wks of training. Performance and physiological responses were measured during an incremental rowing ergometer 'step-test' and a 6-min all-out (6MAO) effort. Respiratory muscle training was undertaken at the 30 repetition maximum load (∼50% of the peak respiratory mouth pressure, PImax or PEmax) using one of two pressure threshold devices.
RESULTS: Table 1. Changes in respiratory muscle function and performance in the 6MAO (mean±SD). *=different from baseline, p <0.05; V=different from preceding time point, p <0.05).
Table 1
Image ToolsThere was no change in minute ventilation (VE) or maximal oxygen uptake (VO2max) in either group at any time point. The IMT group showed a decrease in heart rate (∼3-6 bpm) at all 'step-test' stages, and a decreased sensation of breathlessness (Borg CR10) following the 6MAO effort (11.1%, P = 0.05). There were no significant physiological changes in the EMT group.
CONCLUSIONS: IMT improved rowing performance, but EMT and concurrent IMT/EMT did not.