The Acute Cardiorespiratory Response to Blood-flow Restricted Versus Traditional Exercise Training Regimens (CaRe BFR) (CaRe-BFR)

The Acute Cardiorespiratory Response to Blood-flow Restricted Versus Traditional Exercise Training Regimens (CaRe BFR):4 Randomized Crossover Studies

The investigators hypothesize that BFR exercise regimens result in a different acute cardiorespiratory response pattern compared to traditional exercise regimens. Furthermore, the investigators hypothesize that these patterns differ between healthy participants and participants with COPD.

Regarding secondary objective, the investigators hypothesize that BFR results in lower blood pressure responses compared to traditional exercise training in both healthy and COPD participants.

Study Overview

• Status: Recruiting
• Conditions: COPD
• Intervention / Treatment: Other: Blod flow restriction training

Detailed Description

The investigatorscarry out a monocentric project with 4 randomized crossover studies.

CaRe-BFR Healthy and COPD:

Strength training is performed bilaterally on a Leg Press machine (Leg Press VR2, Cybex International Inc. Medway, MA, USA) using the three set methodology, which is proven to be most effective in enhancing muscle strength.16 Each set is performed to muscular failure, which should be reached within 8-12 repetitions. Training rhythm is set at 1-0-1-0 (i.e. one second for the concentric phase, no pause, one second for the eccentric phase, no pause) and externally paced by a metronome. The training load is 80% of the 1RM. Rest in between sets is 1 minute and participants remain

Strength training BFR is performed bilaterally on a Leg Press machine (Leg Press VR2, Cybex International Inc. Medway, MA, USA) in accordance with evidence-based application guidelines to apply the most effective methodology to enhance muscle strength.17 The exercise consists of a total of 75 repetitions during 4 sets. Training rhythm is set at 1-0-1-0 (i.e. one second for the concentric phase, no pause, one second for the eccentric phase, no pause) and externally paced by a metronome. Set 1 covers 30 repetitions, and the subsequent sets 15 repetitions each. The training load is 30% of the 1RM. Cuffs are mounted bilaterally at the most proximal part of the thigh and inflated to 70% of the individual AOP. Rest in between sets is 1 minute and participants remain seated with the cuffs inflated.

-Endurance is performed bilaterally on a stationary bicycle ergometer (kardiomed 521, proxomed Medizintechnik GmbH, Alzenau, Germany) in an interval setting with loading phases of 1 set with 3 intervals lasting for 2 minutes each; training load is 65% of the peak work rate (PWR). In between the intervals, breaks are standardised to 1 minute. Before the exercise bout, warm-up cycling at 30% PWR for 5 minutes is done to reach a steady state in HR and RER.

Endurance BFR is performed bilaterally on a stationary bicycle ergometer (kardiomed 521, proxomed Medizintechnik GmbH, Alzenau, Germany) in an interval setting with loading phases of 1 set with 3 intervals lasting for 2 minutes and 18 seconds each (matching the overall work performed in EN); training load is 50% of the PWR while limb blood flow is restricted to 50% of the AOP. In between the intervals, breaks are standardised to 1 minute (cuff inflated). Before the exercise bout, warm-up cycling (without BFR) at 30% PWR for 5 minutes is done to reach a steady state in HR and RER.

Measurements:

During exercise, the investigators collect breath-by-breath data (Ergostik, Geratherm Respiratory GmbH, Bad Kissingen, Germany). In addition, continuous SpO2 and HR data via an earlobe probe, and BP response immediately after exercise sets are collected

• Study Type: Interventional
• Enrollment (Estimated): 24
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Christan Clarenbach, Dr. med; Phone Number: 044 255 22 21; Email: Christian.clarenbach@usz.ch
• Study Contact Backup: Name: Manuel Kuhn, PhD Student; Phone Number: 0798526722; Email: manuel.kuhn@usz.ch

Study Locations

• Switzerland
  • Zürich, Switzerland, 8091
    • Recruiting
    • University Hospital Zurich
    • Contact: Manuel Kuhn, MSc; Phone Number: 0432532681; Email: manuel.kuhn@usz.ch
    • Contact: Alexandra Arvaji; Phone Number: 0432530131; Email: alexandra.arvaji@usz.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion and exclusion for the healthy participants are defined by the following criteria.

Inclusion criteria:

• Age ≥ 18 years
• Clinically healthy

Exclusion criteria:

• Physical or intellectual impairment precluding informed consent or protocol adherence
• Non-German speaking (precluding informed consent)
• Pain during exercise of any origin
• Pregnancy
• History of thromboembolic event in the lower extremity
• Resting systolic blood pressure <100 mmHg

Inclusion and exclusion for the COPD participants are defined by the following criteria.

Inclusion criteria:

• Age ≥ 18 years
• Diagnosed COPD according to GOLD-guidelines12

Exclusion criteria:

• Physical or intellectual impairment precluding informed consent or protocol adherence
• Non-German speaking (precluding informed consent)
• Acute or recent (within the last 6 weeks) exacerbation of COPD
• Pain during exercise of any origin
• Pregnancy
• History of thromboembolic event in the lower extremity
• Resting systolic blood pressure <100 mmHg

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: COPD; Diagnosed COPD according to GOLD-guidelines	Other: Blod flow restriction training; includes one strength and one endurance training
Experimental: Healthy; Age ≥ 18 years Clinically healthy	Other: Blod flow restriction training; includes one strength and one endurance training

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Within-subject difference in maximal minute ventilation (VE) between BFR and traditional exercise regimens	investigators will examine VE during strength training and endurance training with and without BFR. Each training sessions will last approximately 20 minutes including baseline CPET. There will be no measurements between the trainings. There will be a minimum wait of 48 hours (wash out timne) until training 2 is performed.	basline (CPET) 20 min, V1 Training (endurance or strengthwith) with or without BFR 20 min; V2 Training (endurance or strengthwith) with or without BFR 20 min

Collaborators and Investigators

• Sponsor: University of Zurich
• Investigators: Principal Investigator: Christian Clarenbach, Dr. med, University of Zurich

Study record dates

Study Major Dates

• Study Start (Actual): May 20, 2022
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: December 3, 2021
• First Submitted That Met QC Criteria: December 17, 2021
• First Posted (Actual): December 20, 2021

Study Record Updates

• Last Update Posted (Actual): May 29, 2024
• Last Update Submitted That Met QC Criteria: May 28, 2024
• Last Verified: May 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: 2021-02038

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No