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Systematic reviews support the benefits of inspiratory muscle training (IMT) for exercise performance. Recently, many health benefits from IMT have been reported in older adults. Therefore, this work reviewed the literature focusing on IMT effects beyond physical performance in older adults, such as cardiorespiratory, metabolic, and postural balance outcomes. Searches were conducted with the following terms: ("respiratory muscle training" OR "inspiratory muscle training") OR ("inspiratory muscle strength training") AND ("elderly" OR "older" OR "aging" OR "aging"), and using the databases: MEDLINE (PubMed), SCOPUS and EUROPE PMC. Of the 356 articles found, 13 matched the inclusion criteria after screening. Based on reviewed studies, four to eight weeks of IMT (Mostly from 50 % up to 75 % of MIP, 7 days/week) improve cardiac autonomic control at rest and post-exercise, cerebrovascular response to orthostatic stress, static and dynamic balance, blood pressure control, endothelial function, and oxidative stress in older adults. The benefits of IMT in cardiac autonomic and vascular functions are reversed after training cessation. It thus appears that IMT promotes broad physiological gains for the older population. It is necessary to carry out more randomized clinical trials on the subject to confirm the findings of this research., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Systematic reviews and meta-analyses support the benefits of inspiratory muscle training (IMT) for sports and clinical populations. A typical application of "standalone" IMT intervention consists of breathing against an inspiratory load (IRL), twice daily, for 5-7 days/wk, for 4-12 wk. However, the application of IRL during aerobic exercise is often seen in a training routine of sports and rehabilitation centers with no evidence-based guide. In this Perspective, we will revisit putative mechanisms underlying the established benefits of "standalone" IMT to support our contention that IMT need not and should not be used during aerobic exercise.

Even though recent studies reported a positive inspiratory muscle training (IMT) effect on cardiovascular autonomic modulation, its underlying mechanisms as the breathing pattern remain unclear. The study aimed to investigate the IMT effects on resting heart rate variability (HRV), spontaneous baroreflex sensitivity (BRS), and spontaneous breathing pattern in older women. Fourteen healthy older women participated in this study, allocated in IMT (50 % MIP; n = 8) or Sham (5% MIP; n = 6) protocols for four weeks. Blood pressure, heart rate, and ventilatory data were continuously recorded before and after interventions. After four weeks, IMT-group increased maximal inspiratory pressure and vagal-mediated HRV, following by the reduction of sympatho-mediated HRV and the inspiratory time during the spontaneous breathing cycle compared to Sham-group, but did not change BRS. Therefore, the shorter inspiratory time suggests a putative mechanism behind improved vagal-mediated HRV post-IMT in older women., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Inspiratory muscle training improved maximal inspiratory pressure (MIP) and vagal-mediated heart rate variability (HRV) in older women. However, it is unknown what occurs if the training is discontinued (detraining protocol). The aim of this study was to investigate the IMT and detraining effects on resting HRV in older women. Twelve healthy older women (60-72 yrs) enrolled in home-based IMT at 50% MIP (IMT-group) or placebo at 5% MIP (Sham-group) protocol for 4 weeks using a mechanical pressure threshold loading device. The participants were not engaged in any other exercise protocol at that time. During IMT and Sham interventions, the inspiratory load was adjusted weekly by the actual MIP and resting heart rate variability (HRV) evaluated. After training cessation (4 weeks of detraining), participants returned to the lab for HRV and MIP recordings. Adherence to IMT was superior to 95%. IMT increased MIP (23 ± 8 cmH 2 O) and vagal-mediated HRV (normalized HF; 37 ± 8%), following by the reduction of sympatho-vagal balance (LF/HF), from the second week to the end of the protocol compared to sham-group. After detraining, IMT-group reduced MIP (-23 ± 8 cmH 2 O) and vagal-mediated HRV (normalized HF; -38 ± 14%) returning to baseline values. In conclusion, MIP and vagal-HRV improvements induced by IMT were reversed by four weeks of detraining., (Copyright © 2021 Elsevier Inc. All rights reserved.)

We tested the hypothesis that inspiratory resistive loading (IRL) increases vagal-mediated complexity of heart rate variability (HRV) in older women. We recorded heart rate continually during 30 breaths with Sham or IRL (30 % of maximal inspiratory pressure) in sitting position. The normalized spectral power in the low (LFn) and high (HFn) frequency bands and the symbolic dynamics measures for 0 V, 2UV and 2 L V were obtained. HFn was higher and LFn was lower during IRL than Sham (p < 0.05). During IRL, 2UV component increased more than Sham (p < 0.05) while 0 V index remained unchanged (p> 0.05). In conclusion, acute IRL improved vagal modulation index of both linear (spectral analysis) and non-linear analysis (symbolic dynamics) in older women., (Copyright © 2020 Elsevier B.V. All rights reserved.)

It was hypothesized that induced inspiratory muscles effort, by an acute inspiratory resistance load (IRL) use, increases the postural sway and the neuromuscular activity of postural muscles in older adults. Fifteen older women breathed spontaneously, controlled (15 cycles/minute), and with acute IRL (15 cycles/minute and target load of 30 % of maximal inspiratory pressure) in random order. The breathing tasks were performed in an orthostatic position (eyes closed) during one minute on a baropodometer plate to acquire center-of-pressure (COP) oscillations and with electromyography (EMG) recording. The root mean square (RMS) of EMG was calculated. COP oscillations were higher with IRL use than spontaneous and controlled breathing tasks, but not between spontaneous and controlled conditions. EMG activity of Tibialis anterior and Soleus muscles were higher with IRL use in comparison to spontaneous and controlled breathing conditions. In conclusion, IRL use influenced the postural control through increased postural sway and neuromuscular compensation of the lower limbs in older women., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: We aimed to investigate the effect of inspiratory muscle training (IMT) on, hemodynamic, cerebrovascular and postural balance responses during orthostatic stress, in older women., Methods: Fourteen elderly women were assigned to perform IMT at 50% of maximal inspiratory pressure (MIP) (IMT group, n = 8) or placebo training at 5% MIP (Sham group, n = 6), in a counter-balanced order, using an inspiratory threshold device for 4 weeks. During the protocol, MIP was tested weekly once. In a second visit, blood pressure, heart rate, stroke volume, cardiac output, middle cerebral artery blood flow velocity (MCAv), and ventilation parameters were recorded continuously at rest and during orthostatic stress testing, which was conducted on a force plate to measure center-of-pressure (COP) oscillations (postural balance) and the electromyographic activity of the right medial gastrocnemius and tibialis anterior., Results: IMT increased MIP from second to 4th week. The drops in MCAv, stroke volume, and cardiac output, as well as COP displacements during initial orthostasis decreased post-IMT., Conclusion: IMT improves the interplay of the respiratory pump, hemodynamic, cerebrovascular and postural balance responses during orthostatic stress in older women.

The acute inspiratory resistive load (IRL) may increase the respiratory pump contributes to hemodynamic responses during orthostatic stress. However, IRL effects on cerebrovascular and postural control interplay is unknown. Fourteen older women (65 ± 4 years) performed two orthostatic tests with spontaneous breathing through acute experimental (-9 cm.H 2 O) or sham load impedance (0 cmH 2 O) connected to a pneumotachograph for breath-by-breath recordings on a facemask. Both tests were executed on a force plate, for postural balance analysis, and electromyographic activity records of calf muscles. Blood pressure, middle cerebral artery blood velocity (MCAv), heart rate (HR), stroke volume (SV), and cardiac output (CO) were continuously recorded. IRL reduced postural instability in the first five seconds at orthostatic position compared to sham. Although the mean blood pressure and MCAv were similar in both conditions, IRL reduced the SV and CO drops, and time to recover MCAv. Therefore, IRL improved postural control, CO and MCAv responses during initial orthostasis., Competing Interests: Declaration of Competing Interest None of the authors have any financial or personal relationships with people or organizations., (Copyright © 2020. Published by Elsevier B.V.)

Purpose: Aging impairs the autonomic balance reducing the vagal and increasing the sympathetic components of heart rate variability (HRV) and this could be associated with a decline in physical capacity. Inspiratory muscle training (IMT) is a possible tool to attenuate this physical capacity decline in older women. The aim of this study was to investigate the influence of IMT in the older women on physical capacity and autonomic cardiac modulation at rest and post exercise., Methods: 20 female participants 60-72 years old were randomly allocated in two groups. One group underwent IMT set at 50% of maximum inspiratory pressure (MIP), every day for 4 weeks (IMT-group). The placebo group performed the same training procedure but with a minimal resistance (5% MIP; PLA-group). Every week, the IMT load was readjusted and the HRV evaluated at rest. The six-minute walk test (6MWT) was performed once pre and post IMT-intervention. The IMT-group and PLA-group performed the same test and intervention procedures., Results: After a 5 weeks intervention, the MIP had significantly improved in the IMT-group but not in the PLA-group (p < 0.01; es = 1.17). The high frequency power of the HRV spectrum had already improved by the second week (p < 0.01; es = 1.13) and remained elevated until the last week of intervention (p < 0.01; es = 1.43). The same positive results were described in 6MWT distance (p = 0.04; es = 0.39) and the change (∆) of heart rate recovery (HRR) from 1 min (p = 0.02; es = 0.68)., Conclusion: IMT increases HRV, improves 6MWT distance and HRR.