Critical inspiratory pressure - a new methodology for evaluating and training the inspiratory musculature for recreational cyclists: study protocol for a randomized controlled trial

Author(s)

Rehder-Santos, Patricia ^[1] ; Minatel, Vinicius ^[1] ; Milan-Matzos, Juliana Cristina ^[1] ; Signini, Etore De Favari ^[1] ; de Abreu, Raphael Martins ^[1] ; Dato, Carla Cristina ^[2] ; Catai, Aparecida Maria ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Phys Therapy, Cardiovasc Phys Therapy Lab, Nucleus Res Phys Exercise, Via Washington Luiz, Km 235, CP 676, BR-13565905 Sao Carlos, SP - Brazil

^[2] Cent Univ Paulista, Nutr Course, Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Trials; v. 20, MAY 7 2019.
• Web of Science Citations: 1

Abstract

BackgroundInspiratory muscle training (IMT) has brought great benefits in terms of improving physical performance in healthy individuals. However, there is no consensus regarding the best training load, as in most cases the maximal inspiratory pressure (MIP) is used, mainly the intensity of 60% of MIP. Therefore, prescribing an IMT protocol that takes into account inspiratory muscle strength and endurance may bring additional benefits to the commonly used protocols, since respiratory muscles differ from other muscles because of their greater muscular resistance. Thus, IMT using critical inspiratory pressure (PThC) can be an alternative, as the calculation of PThC considers these characteristics. Therefore, the aim of this study is to propose a new IMT protocol to determine the best training load for recreational cyclists.MethodsThirty recreational cyclists (between 20 and 40years old) will be randomized into three groups: sham (SG), PThC (CPG) and 60% of MIP, according to age and aerobic functional capacity. All participants will undergo the following evaluations: pulmonary function test (PFT), respiratory muscle strength test (RMS), cardiopulmonary exercisetest (CPET), incremental inspiratory muscle endurance test (iIME) (maximal sustained respiratory pressure for 1min (PThMAX)) and constant load test (CLT) (95%, 100% and 105% of PThMaX) using a linear load inspiratory resistor (PowerBreathe K5). The PThC will be calculated from the inspiratory muscle endurance time (T-LIM) and inspiratory loads of each CLT. The IMT will last 11weeks (3 times/week and 55min/session). The session will consist of 5-min warm-up (50% of the training load) and three sets of 15-min breaths (100% of the training load), with a 1-min interval between them. RMS, iIME, CLT and CPET will be performed beforehand, at week 5 and 9 (to adjust the training load) and after training. PFT will be performed before and after training. The data will be analyzed using specific statistical tests (parametric or non-parametric) according to the data distribution and their respective variances. A pvalue <0.05 will be considered statistically significant.DiscussionsIt is expected that the results of this study will enable the training performed with PThC to be used by health professionals as a new tool to evaluate and prescribe IMT.Trial registrationClinicalTrials.gov, NCT02984189. Registered on 6 December 2016. (AU)

• FAPESP's process: 16/22215-7 - Impact of inspiratory muscle training and aging on metabolic mapping, autonomic modulation, and cardiovascular, respiratory and metabolic responses, and prediction of cardiorespiratory health through wearables
• Grantee: Aparecida Maria Catai
• Support Opportunities: Research Projects - Thematic Grants