The effect of walking training on respiratory function and performance in older females

Background: Sarcopenia affects respiratory system function, potentially decreasing thoracic cavity pressure development and exercise performance. Research question: To investigate the role of walking training on reductions in respiratory muscle strength which are conceivably due to aging. Type of study: Randomised control study. Methods: Twenty-six older females (range: 60-69 yrs) were assessed for respiratory function, respiratory muscle strength and walking performance. Thirteen participants were then randomly assigned to a walking training group (WT) for eight weeks and were required to undertake three supervised walking sessions per week at 60% of the heart rate reserve value. Sessions ranged from 20 to 40 minutes duration. Results: Following the training, the amount of change in respiratory muscle strength was superior in the WT group in comparison to the control group (9% for inspiratory and expiratory strength, p<0.05). Further, the WT group demonstrated an improvement in treadmill walking performance of 11% (p<0.05), whilst treadmill walking performance for the controls remained unchanged. Despite such improvements, there were no changes to respiratory variables measured at three submaximal velocities during the treadmill assessment. Conclusions: The improvement in respiratory muscle strength indicates the strong involvement of the respiratory system during walking training; however, the lack of change in respiratory variables during submaximal walking indicates that the respiratory system may not be an exercise limiting factor in 60-69 yr-old females during submaximal tasks. In contrast, at elevated walking intensities, the improved strength of the respiratory muscles may assist in a greater tolerance of the required workload.