Acute Autonomic Responses During and After BFR Training

NCT07722403 | Not Yet Recruiting

• 1 other identifier: HOLD TIGHT 2.0
• Study Type: interventional
• Target: 48
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to compare how the body's nervous system responds to two different types of leg exercise in young and older adults. One type is low-intensity exercise with blood flow restriction (BFR) , where a cuff partially reduces blood flow to the legs during exercise. The other type is traditional high-intensity resistance training (HIRT), which uses heavier weights. The main questions it aims to answer are: Does low-intensity exercise with BFR cause less stress on the nervous system during exercise compared to high-intensity training? Does low-intensity exercise with BFR lead to faster recovery of the nervous system after exercise compared to high-intensity training? Do these responses differ between young adults and older adults? Researchers will compare low-intensity exercise with BFR to high-intensity training to see which approach is gentler on the nervous system during and after exercise. Participants will: Attend three visits to the research lab Complete a strength test on leg exercise machines Perform two separate exercise sessions: one with low-intensity exercise and BFR, and one with high-intensity training Have their heart rate, blood pressure, and heart rate variability monitored continuously during and after each exercise session

Conditions

Blood Flow Restriction Exercise; Aging

Keywords

blood flow restriction; cardiovagal modulation; resistance exercise; young adults; older adults; recovery

Outcome Measures

Primary Outcomes (1)

• Changes in Time-Domain Heart Rate Variability Indices

  Mean change from baseline in time-domain heart rate variability indices: RMSSD (root mean square of successive differences, reflecting vagal modulation), SDNN (standard deviation of normal-to-normal intervals, reflecting overall autonomic modulation), and pNN50 (percentage of successive R-R intervals \>50 ms). These indices will be derived from continuous R-R interval recordings (Finapres Nova) during supine rest. Higher values indicate better parasympathetic modulation and autonomic flexibility.

  Baseline (15-minute seated rest); during exercise (continuous throughout the 30-minute exercise bout); and 30 minutes into recovery (seated position)

Secondary Outcomes (4)

• Changes in Frequency-Domain Heart Rate Variability Indices

  Baseline (15-minute seated rest); during exercise (continuous throughout the 30-minute exercise bout); and 30 minutes into recovery (seated position)

• Changes in Non-Linear Heart Rate Variability Indices

  Baseline (15-minute seated rest); during exercise (continuous throughout the 30-minute exercise bout); and 30 minutes into recovery (seated position)

• Changes in Cardiovagal Baroreflex Sensitivity (BRS)

  Baseline (15-minute seated rest); during exercise (continuous throughout the 30-minute exercise bout); and 30 minutes into recovery (seated position)

• Changes in Blood Pressure

  Baseline (15-minute seated rest); during exercise (continuous throughout the 30-minute exercise bout); and 30 minutes into recovery (seated position)

Study Arms (3)

Low-Intensity + Blood Flow Restriction

EXPERIMENTAL

Other: Low-Intensity Resistance Training with Blood Flow Restriction (LIRT-BFR)

High-Intensity Resistance Training (HIRT)

ACTIVE COMPARATOR

Other: High-Intensity Resistance Training (HIRT)

No exercise or blood flow restriction

NO INTERVENTION

Interventions

High-Intensity Resistance Training (HIRT) OTHER

Participants perform bilateral knee extensions and leg curls at 75% of their one-repetition maximum (1RM). The protocol consists of 3 sets of 10 repetitions with 2-minute rest intervals between sets. Total exercise duration is approximately 30 minutes.

High-Intensity Resistance Training (HIRT)

Low-Intensity Resistance Training with Blood Flow Restriction (LIRT-BFR) OTHER

Participants perform bilateral knee extensions and leg curls at 30% of their one-repetition maximum (1RM) while a pneumatic cuff is applied to the most proximal portion of both thighs. The cuff is inflated to 1.3 times the individual's ankle systolic blood pressure. The protocol consists of 4 sets of 20 repetitions with 30-second rest intervals between sets. Total exercise duration is approximately 30 minutes. Cuff pressure is maintained continuously throughout sets and rest periods and is released immediately after the final repetition.

Low-Intensity + Blood Flow Restriction

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Young adults aged 18-24 years
• Older adults aged 60 years and above
• Willing and able to provide written informed consent
• Able to comply with study procedures and visit schedule

You may not qualify if:

• Medications affecting cardiac activity (e.g., beta-blockers, calcium channel blockers, antiarrhythmics)
• Tobacco use
• Sleep apnea
• Body mass index (BMI) greater than 30 kg/m²
• Regular exercise training (more than 150 minutes per week for more than 6 months)
• History of coronary heart disease
• History of stroke
• History of oncological disease
• History of major cardiovascular events
• Peripheral vascular disease
• Uncontrolled hypertension
• Diabetes mellitus
• Unstable angina
• Active kidney or liver disease
• Chronic obstructive pulmonary disease (COPD)

Sponsors & Collaborators

• Egas Moniz - Cooperativa de Ensino Superior, CRL: lead

Study Sites (1)

Egas Moniz School of Health and Science

Almada, Monte Da Caparica, 2829-511, Portugal

Location

Related Publications (5)

• Oliveira RS, Vitor da Costa M, Pedro RE, Polito MD, Avelar A, Cyrino ES, Nakamura FY. Acute cardiac autonomic responses after a bout of resistance exercise. Sci Sports. 2012;27(6):357-364.

  BACKGROUND

• Grassler B, Thielmann B, Bockelmann I, Hokelmann A. Effects of different exercise interventions on heart rate variability and cardiovascular health factors in older adults: a systematic review. Eur Rev Aging Phys Act. 2021 Nov 17;18(1):24. doi: 10.1186/s11556-021-00278-6.

  PMID: 34789148 BACKGROUND

• Okuno NM, Pedro RE, Leicht AS, de Paula Ramos S, Nakamura FY. Cardiac autonomic recovery after a single session of resistance exercise with and without vascular occlusion. J Strength Cond Res. 2014 Apr;28(4):1143-50. doi: 10.1519/JSC.0000000000000245.

  PMID: 24077384 BACKGROUND

• Ganzarolli Stevanatto LC, Venturini Ferreira ML, Bonganha V, de Souza GV, Cavaglieri CR, Chacon Mikahil MPT. Acute cardiac autonomic responses to resistance exercise with and without blood flow restriction. Sci Sports. 2022;37(5-6):454-458. DOI: 10.1016/j.scispo.2022.04.001

  BACKGROUND

• Ferreira MLV, Sardeli AV, Souza GV, Bonganha V, Santos LDC, Castro A, Cavaglieri CR, Chacon-Mikahil MPT. Cardiac autonomic and haemodynamic recovery after a single session of aerobic exercise with and without blood flow restriction in older adults. J Sports Sci. 2017 Dec;35(24):2412-2420. doi: 10.1080/02640414.2016.1271139. Epub 2016 Dec 28.

  PMID: 28029066 BACKGROUND

Central Study Contacts

Xavier Melo, PhD

CONTACT

+351 212946700; xmelo@egasmoniz.edu.pt

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Outcomes will be assessed by the same experts in every time point. Participants and evaluators will be blinded until arrival of the participant for the first experimental condition.
• Purpose: SUPPORTIVE CARE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Parallel group crossover randomized trial

Study Record Dates

• First Submitted: July 20, 2026
• First Posted: July 23, 2026
• Study Start (Estimated): October 5, 2026
• Primary Completion (Estimated): May 14, 2027
• Study Completion (Estimated): June 25, 2027
• Last Updated: July 23, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Data requests can be submitted starting 9 months after article publication and the data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis.
• Access Criteria: Access to trial IPD can be requested by qualified researchers engaging in independent scientific research and will be provided following review and approval of a research proposal and Statistical Analysis Plan (SAP) and execution of a Data Sharing Agreement (DSA). For more information or to submit a request, please contact xmelo@egasmoniz.edu.pt

Locations

PT (1)