NCT02984189

Brief Summary

Introduction: The inspiratory muscle training (IMT) has showed great benefits to the respiratory, autonomic system, and mainly to the improvement of physical performance in healthy subjects. The latter is related to the improvement of respiratory muscle strength, decreased of dyspnoea, peripheral fatigue and delay in activation of muscle metaboreflex during exercise. However, there is no consensus about the best training load to IMT, because the prescription has been done only using percentage of the maximal inspiratory pressure (MIP), and 60% of MIP has been the most used. Therefore, the IMT prescription protocol that takes into account the respiratory muscle strength and endurance can provide additional benefits to protocols commonly applied, once that respiratory muscle differs from the other muscles due to its greater muscle endurance. In the sense, the IMT using inspiratory critical pressure (PThC) comes up with an alternative, since the PThC calculation considers these characteristics. Objective:To evaluate the effect of the IMT, using PThC, on cardiovascular, respiratory, metabolic and autonomic responses in recreational cyclists and compare it to a IMT using 60% of MIP. Methods: Thirty men recreational cyclists (20-40 years), will be randomized to placebo group (PG, n = 10), PThC group (PTHCG, n = 10) and 60% of MIP group (60G, n = 10), taking into account the age and functional aerobic capacity. All subjects will perform the following evaluations: cardiovascular autonomic tests \[heart rate variability (HRV) and blood pressure variability (BPV) at rest and after active postural change\], pulmonary function testing, respiratory muscle strength (RMS) test, cardiopulmonary exercise testing (CPET), incremental respiratory muscle endurance test (iRME) \[maximum respiratory pressure sustained for 1 minute (PThMAX)\] and constant respiratory loads test (95%, 100% and 105% of PThMAX), both using an linear inspiratory load resistor (PowerBreathe K5). The PThC will be obtained from the linear regression using the time(TLIM) of and load of each constant test (95%, 100% and 105% PThMAX). During evaluations, the ECG (BioAmp FE132), blood pressure (BP), using Finometer Pro (Finapress Medical Systems) and respiration (Marazza) signals will be acquired. The signals will be coupled by data acquisition and analysis device (Power Lab 8/35) and sampled at 1000 Hz. Moreover, the oxyhemoglobin, deoxyhemoglobin and total hemoglobin responses will be measured by near-infrared spectroscopy (NIRS) (Oxymon MKIII), sampled at 250Hz. The IMT will be performed for 11 weeks (3 times/week, 1-hour duration). The session will consist of 5-min warm-up (50% of the training load) and 3 sets of 15 minutes (breathing against 100% of the training load) with 1-min interval between them. Heart rate and BP will be monitored in all training sessions. The RMS, iRME, respiratory constant load tests and CPET will be performed before and after the training, and in the 3rd and 7th week (for training load adjustment). The pulmonary function testing and the cardiovascular autonomic tests will be performed only before and after training. The data will be analyzed by specific statistical tests (parametric and nonparametric) according to the data distribution and their respective variances. Significance will be set at p\<0.05. Expected results: It is expected that the training performed by PTHCG, when compared to training performed by 60G and PG, promotes: greater improvementin workload (Watts) and peak oxygen uptake (VO2peak); increasing in MIP and iRME; decreasing of dyspnoea and peripheral fatigue; delay in activation of muscle metaboreflex in the CPET and iRME; improvement incardiac parasympathetic autonomic modulation and reducing cardiac and peripheral sympathetic modulation. Moreover, it is expected that the results can provide information for a better understanding of the responses obtained by the PThC training in the different evaluated systems. In addition, these results will allow the use of this method by health professionals as a new assessment tool and IMT prescription.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
30

participants targeted

Target at below P25 for phase_2 healthy

Timeline
Completed

Started Feb 2016

Typical duration for phase_2 healthy

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

February 1, 2016

Completed
10 months until next milestone

First Submitted

Initial submission to the registry

November 29, 2016

Completed
7 days until next milestone

First Posted

Study publicly available on registry

December 6, 2016

Completed
2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 1, 2018

Completed
2 months until next milestone

Study Completion

Last participant's last visit for all outcomes

February 1, 2019

Completed
Last Updated

December 6, 2016

Status Verified

December 1, 2016

Enrollment Period

2.8 years

First QC Date

November 29, 2016

Last Update Submit

December 1, 2016

Conditions

Keywords

Physical ExercisePhysical TherapyPhysical PerformanceCritical PowerRespiratory Muscle

Outcome Measures

Primary Outcomes (2)

  • Performance in exercise evaluated by measurement the maximal or peak comsumption the oxygen (VO2max or peak)

    The performance will be evaluated by measurement the maximal or peak comsumption the oxygen (VO2max or peak), determinated by the cardiopulmonary exercise testing.

    Three years

  • Performance in exercise evaluated by measurement the work load (W)

    The performance will be evaluated by measurement the work load (W), determinated by the cardiopulmonary exercise testing. The evaluation will realize before, fifth and ninth weeks and after the training.

    Three years

Secondary Outcomes (5)

  • Cardiovascular responses to inspiratory muscle training

    Three years

  • Respiratory responses to inspiratory muscle training

    Three years

  • Metabolic responses to inspiratory muscle training

    Three years

  • Autonomic responses to inspiratory muscle training

    Three years

  • Metaboreflex activation to inspiratory muscle training

    Three years

Study Arms (3)

Inspiratory Critical Pressure Group

EXPERIMENTAL

Inspiratory Critical Pressure will be used for training and will be determined, from a progressive inspiratory threshold-loading test will start with 50%MIP followed by 10%MIP increments, every 3min until subjects reached a load that there were unable to sustain for at least 1min (PThMAX). On another day, the subjects will perform a constant inspiratory loading test against a resistance of 95%, 100% and 105%PThMAX, for as long as they could tolerate. The intensity loads will be applied according the results of block randomization. The time elapsed until task failure was defined as inspiratory muscle endurance time, and will use to set the PThC. The respiratory work done (inspiratory pressure values) will be plotted in abscissa and the time-to-exhaustion in ordinate, and a linear regression going through the 3 points will be applied using the pressure-1/t relationship. The slope of the parallel line displaced downward projecting to the origin produce the PThC value.

Other: Inspiratory muscle training

60% Maximal Inspiratory Pressure Group

ACTIVE COMPARATOR

60% of maximal inspiratory pressure will be used for training.

Other: Inspiratory muscle training

Sham Group

SHAM COMPARATOR

6 cmH20 will be used for training.

Other: Inspiratory muscle training

Interventions

The inspiratory muscle training (IMT) will be realized, to compare three intensities differents the training (Inspiratory critical pressure, 60% maximal inspiratory pressure and sham). The IMT will be performed for 11 weeks (33 sessions, 3 times/week, 1-hour duration). The session will consist of 5-min warm-up (50% of the training load) and 3 sets of 15 minutes (breathing against 100% of the training load) with 1-min interval between them, using a linear inspiratory load resistor (Device: PowerBreathe K5).

60% Maximal Inspiratory Pressure GroupInspiratory Critical Pressure GroupSham Group

Eligibility Criteria

Age20 Years - 40 Years
Sexmale
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Apparently Healthy;
  • Practicing cycling for at least 6 months continuous and at least 150 min weekly as active \[by the American College of Sports Medicine (2011)\].

You may not qualify if:

  • Participants can not be: smokers, alcoholics, illegal drug users or drugs that may interfere in the search results;
  • Diagnosis of cardiorespiratory and metabolic disease;
  • Absence of ischemic and conduction ECG alterations at rest or during the clinical exercise test;
  • Body mass index (BMI) \<30 kg/m²;
  • Presence of respiratory muscle weakness \[maximal inspiratory pressure (MIP \<60% predicted);
  • Alterations in the pulmonary function test (PFT) or other test;
  • Have performed of inspiratory muscle training in the last six months.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Federal University of Sao Carlos

São Carlos, São Paulo, 676, 13565-905, Brazil

RECRUITING

Related Publications (7)

  • American Thoracic Society/European Respiratory Society. ATS/ERS Statement on respiratory muscle testing. Am J Respir Crit Care Med. 2002 Aug 15;166(4):518-624. doi: 10.1164/rccm.166.4.518. No abstract available.

    PMID: 12186831BACKGROUND
  • Garber CE, Blissmer B, Deschenes MR, Franklin BA, Lamonte MJ, Lee IM, Nieman DC, Swain DP; American College of Sports Medicine. American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Med Sci Sports Exerc. 2011 Jul;43(7):1334-59. doi: 10.1249/MSS.0b013e318213fefb.

    PMID: 21694556BACKGROUND
  • Balady GJ, Arena R, Sietsema K, Myers J, Coke L, Fletcher GF, Forman D, Franklin B, Guazzi M, Gulati M, Keteyian SJ, Lavie CJ, Macko R, Mancini D, Milani RV; American Heart Association Exercise, Cardiac Rehabilitation, and Prevention Committee of the Council on Clinical Cardiology; Council on Epidemiology and Prevention; Council on Peripheral Vascular Disease; Interdisciplinary Council on Quality of Care and Outcomes Research. Clinician's Guide to cardiopulmonary exercise testing in adults: a scientific statement from the American Heart Association. Circulation. 2010 Jul 13;122(2):191-225. doi: 10.1161/CIR.0b013e3181e52e69. Epub 2010 Jun 28. No abstract available.

    PMID: 20585013BACKGROUND
  • Borg GA. Psychophysical bases of perceived exertion. Med Sci Sports Exerc. 1982;14(5):377-81.

    PMID: 7154893BACKGROUND
  • HajGhanbari B, Yamabayashi C, Buna TR, Coelho JD, Freedman KD, Morton TA, Palmer SA, Toy MA, Walsh C, Sheel AW, Reid WD. Effects of respiratory muscle training on performance in athletes: a systematic review with meta-analyses. J Strength Cond Res. 2013 Jun;27(6):1643-63. doi: 10.1519/JSC.0b013e318269f73f.

    PMID: 22836606BACKGROUND
  • Hautmann H, Hefele S, Schotten K, Huber RM. Maximal inspiratory mouth pressures (PIMAX) in healthy subjects--what is the lower limit of normal? Respir Med. 2000 Jul;94(7):689-93. doi: 10.1053/rmed.2000.0802.

    PMID: 10926341BACKGROUND
  • Rehder-Santos P, Minatel V, Milan-Mattos JC, Signini EF, de Abreu RM, Dato CC, Catai AM. Critical inspiratory pressure - a new methodology for evaluating and training the inspiratory musculature for recreational cyclists: study protocol for a randomized controlled trial. Trials. 2019 May 7;20(1):258. doi: 10.1186/s13063-019-3353-0.

MeSH Terms

Conditions

Motor Activity

Condition Hierarchy (Ancestors)

Behavior

Study Officials

  • Aparecida M Catai, PhD

    Universidade Federal de Sao Carlos

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Patricia Rehder-Santos, Master

CONTACT

Study Design

Study Type
interventional
Phase
phase 2
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, INVESTIGATOR
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor Aparecida Maria Catai

Study Record Dates

First Submitted

November 29, 2016

First Posted

December 6, 2016

Study Start

February 1, 2016

Primary Completion

December 1, 2018

Study Completion

February 1, 2019

Last Updated

December 6, 2016

Record last verified: 2016-12

Data Sharing

IPD Sharing
Will not share

Locations