Comparison between Two Inspiratory Muscle Training Protocols, Low Loads versus High Loads, in Institutionalized Elderly Women: A Double-Blind Randomized Controlled Trial

<b><i>Background:</i></b> Aging results in a decline in the function of the respiratory muscles. Inspiratory muscle training is presented as a possible solution to attenuate the loss of respiratory function in the elderly. The objective of the study was to evaluate and compare the efficacy of 2 protocols with inspiratory muscle training (IMT), low loads and high loads, to improve respiratory strength, functional capacity and dyspnea in institutionalized elderly women, over 65 years. <b><i>Methods:</i></b> The study was a controlled, randomized, double-blind trial and with allocation concealment performed on 26 institutionalized elderly women distributed in 2 groups, the high-intensity group (HIG) and low-intensity group (LIG). Over an 8-week period an IMT protocol was followed 5 days/week, 15 min/day. The HIG trained with a load of 40% of the maximum inspiratory pressure (MIP) and the LIG with 20%. MIP, maximum expiratory pressure (MEP), functional capacity and dyspnea were evaluated. <b><i>Results:</i></b> After training, in the HIG MIP, MEP and functional capacity increased 52, 16 and 7%, respectively (<i>p</i> = 0.000, <i>p</i> = 0.001, <i>p</i> = 0.001) and in the LIG 30, 18 and 9%, respectively (<i>p</i> = 0.002, <i>p</i> = 0.014, <i>p</i> = 0.001). The improvement in MIP was significantly higher in the HIG than in the LIG (<i>p</i> = 0.042). <b><i>Conclusion:</i></b> IMT with low and high loads improves respiratory muscle strength and functional capacity in institutionalized elderly women. In addition, high loads were significantly more effective to improve MIP.