NCT06596304

Brief Summary

Aging leads to declines in functional capacity and effort tolerance. Muscle strength remains stable from ages 25 to 50 but declines significantly after age 60, affecting activities like stair climbing and walking, reducing autonomy and independence. While muscle atrophy is a significant factor, macrovascular endothelial dysfunction also impairs skeletal muscle performance in older adults. Nitric oxide (NO), produced by endothelial cells, regulates vascular homeostasis and contractile function. NO enhances muscle fiber shortening velocity, reduces twitch time-to-peak contraction, and increases the rate of force development. Aging-related endothelial dysfunction reduces NO availability, leading to reduced muscle mass and sarcopenia via decreased skeletal muscle perfusion. Increased arterial stiffness disrupts ventricular-vascular coupling, reducing cardiac output and contributing to age-related muscle weakness. Additionally, microvascular function decreases with age, contributing to altered physical work perception and reduced function. Low capillary density is linked to reduced walking speed in older adults and reduced walking time in peripheral arterial disease patients, supporting the microvasculature\'s role in functional performance. Reduced muscle mass also increases central hemodynamic load, impacting arterial stiffness and cardiac function. Resistance training (RT) is recommended to mitigate aging effects like loss of strength and muscle mass and reduce cardiovascular risk and all-cause mortality. Guidelines suggest 1-3 sets of 8-12 repetitions at 60-80% of the individual\'s repetition maximum (1RM), performed at least twice a week. However, older adults with osteoarthritis and cardiovascular conditions often cannot tolerate high mechanical stress and are prescribed lower intensity-resistance training (LIRT) at 40-50% of 1RM, typically yielding negligible muscle hypertrophy or strength gains. Blood flow restriction (BFR) training, which applies pressure bands to restrict blood flow during LIRT, increases muscle volume and strength. While BFR shows promise, it can cause acute increases in arterial stiffness and blood pressure in older adults, necessitating caution in its prescription. This study aims to compare macrovascular and microvascular function responses to acute resistance exercise with and without BFR in young and older adults. We hypothesize that older adults will show a more pronounced increase in macrovascular and microvascular dysfunction following resistance exercise compared to younger participants. In this parallel group randomized controlled trial, participants will be randomly assigned to either LIRT-BFR or high-intensity resistance training (HIRT). Each participant will attend three sessions: a familiarization session and two experimental sessions involving the randomized exercise conditions. Measurements of brachial blood pressure, heart rate, and macrovascular and microvascular function will be taken at rest and during recovery periods post-exercise.

Trial Health

57
Monitor

Trial Health Score

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

Trial has exceeded expected completion date
Enrollment
52

participants targeted

Target at P25-P50 for not_applicable

Timeline
Completed

Started Oct 2024

Shorter than P25 for not_applicable

Geographic Reach
1 country

2 active sites

Status
recruiting

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

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

September 11, 2024

Completed
8 days until next milestone

First Posted

Study publicly available on registry

September 19, 2024

Completed
12 days until next milestone

Study Start

First participant enrolled

October 1, 2024

Completed
7 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 1, 2025

Completed
2 months until next milestone

Study Completion

Last participant's last visit for all outcomes

July 1, 2025

Completed
Last Updated

October 23, 2024

Status Verified

October 1, 2024

Enrollment Period

7 months

First QC Date

September 11, 2024

Last Update Submit

October 19, 2024

Conditions

Keywords

blood flow restrictionResistance trainingmicrovascular functionarterial stiffnessblood pressureyoung adultsolder adults

Outcome Measures

Primary Outcomes (4)

  • Change in macrovascular function

    We will use the slowing of the pulse wave velocity (PWV) recorded between the upper arm and the wrist as an index of macrovascular function. PWV is inversely related to arterial distensibility; a widening of the brachial artery cross-section will cause a drop in post-occlusive PWV. Macrovascular function will be evaluated using EndoFMS (Vicorder, Berlin, Germany), and the response parameters are PWVmin and PWV% change from pre-occlusion values. The percentage change from initial PWV is called FMS. The default cuff placement is a 10 cm brachial cuff on the upper arm and a 7 cm wrist cuff on the selected limb. The test is performed with the patient lying horizontally, the right arm extended at a 60-degree angle, and the hand rotated palm up. After the patient relaxes, the test starts with a target occlusion pressure 30 mmHg above systolic pressure. Brachial PWV is measured between the wrist and upper arm over 10 minutes, with a 5-minute occlusion period.

    At rest and re-evaluated 5- and 30-minutes into recovery following the experimental conditions

  • Change in central arterial stiffness

    To measure arterial stiffness, we will assess carotid-femoral pulse wave velocity (cPWV) using a Vicorder module (Berlin, Germany). Participants will be in a reclined position, with a minimum of 10 minutes of rest. A 100 mm blood pressure cuff will encircle the upper thigh, and a 30 mm partial cuff will be applied around the neck at the level of the carotid arteries, above the thyroid prominence. The direct path length will be measured from the suprasternal angle to the middle of the femoral blood pressure cuff by the same operator. Both cuffs will be simultaneously inflated to 60 mm Hg to capture femoral and carotid waveforms. Continuous recordings will be obtained beat-to-beat for at least 3 minutes. Automated software will determine the wave\'s foot using an intersecting tangent algorithm. The time delay between the foot of the carotid and femoral waveforms will provide the average TT every 3.5 seconds.

    At rest and re-evaluated 5- and 30-minutes into recovery following the exercise condition

  • Change in blood pressure

    The brachial artery pulse waveform obtained oscillometrically, will be analyzed using the Pulse Wave Analysis (PWA) function of the Vicorder® device (Berlin, Germany), and the aortic waveform calculated using a transfer function. This enables calculation of arterial system parameters, including cSBP, augmentation pressure (AugPress), augmentation index (AugInd), central peripheral pressure (cPP), cardiac output, and total peripheral resistance. Initial waves will be omitted, and good-quality consecutive pulse waves will be analyzed.

    at rest and re-evaluated after each set and 5- and 30-minutes into recovery following the exercise condition

  • Change in microvascular function

    Microvascular function will be assessed using EndoPAR (Vicorder, Berlin, Germany). Participants will be in a supine position with their arms comfortably positioned. Changes in the peripheral arterial dilation ratio (PAR) signal to reactive hyperemia (RH) will be measured at the fingertip with photoplethysmographs and an inflating device controlled by a computer algorithm. The RH procedure consists of a 30-second calibration, a 5-minute baseline recording, followed by 5 minutes of blood flow occlusion of the test arm using an upper arm blood pressure cuff inflated to 30 mmHg above the patient's systolic brachial pressure. After cuff deflation, the PAR tracing will be recorded for another 3 minutes. The software automatically normalizes this ratio to the concurrent signal from the contralateral, non-occluded forearm to correct for confounding variables. This ratio is then multiplied with a baseline correction factor to obtain Measured Peak, Max Reference Peak, and Max PAR.

    At rest and re-evaluated 5- and 30-minutes into recovery following the exercise condition

Study Arms (3)

Resistance training with blood flow restriction

EXPERIMENTAL
Other: Low intensity-resistance training with lower limb blood flow restriction

Resistance training without blood flow restriction

ACTIVE COMPARATOR
Other: High Intensity Resistance Training

No exercise or blood flow restriction

NO INTERVENTION

Interventions

In the LIRT-BFR, participants will perform 4 sets of 20 bilateral leg presses and knee extensions repetitions with BFR at 30% of 1-RM, with 30-second rest intervals between sets, in an estimated total of 30-minute session per participant. Cuffs will be placed in the upper thighs and inflated with a pressure that is 1.3 times the individual's ankle systolic blood pressure in the data collection day for the entirety of the training session with a commercial cuff (width×length; 11×85 cm, SC10™, Hokanson, Inc., WA, USA).

Resistance training with blood flow restriction

In the HIRT participants will perform bilateral leg presses and knee extension without BFR at 75% of one-repetition maximum (1-RM), for 3 sets of 10 reps, with 2-minute rest intervals, in an estimated total of 30-minute session per participant.

Resistance training without blood flow restriction

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Aged between 18-30 years and those over 60 years.

You may not qualify if:

  • Past or current history of coronary heart disease, stroke, oncological disease, or major cardiovascular events.
  • Individuals who had undergone surgery within the last two months
  • Body mass index (BMI) greater than 30 kg/m²
  • Declared sleep apnea
  • Active kidney or liver disease
  • Active tobacco smokers
  • Sensory impairments
  • Neurological or orthopedic functional impairments, musculoskeletal pathologies affecting exercise capacity
  • Physically active for more than six months with a weekly activity level of 1,000 MET/min.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (2)

Egas Moniz School of Health and Science

Almada, Monte Da Caparica, 2829-511, Portugal

NOT YET RECRUITING

Egas Moniz School of Health and Science

Almada, Setúbal District, 2829-511, Portugal

RECRUITING

Related Publications (9)

  • Fahs CA, Rossow LM, Thiebaud RS, Loenneke JP, Kim D, Abe T, Beck TW, Feeback DL, Bemben DA, Bemben MG. Vascular adaptations to low-load resistance training with and without blood flow restriction. Eur J Appl Physiol. 2014 Apr;114(4):715-24. doi: 10.1007/s00421-013-2808-3. Epub 2013 Dec 31.

    PMID: 24375201BACKGROUND
  • Horiuchi M, Stoner L, Poles J. The effect of four weeks blood flow restricted resistance training on macro- and micro-vascular function in healthy, young men. Eur J Appl Physiol. 2023 Oct;123(10):2179-2189. doi: 10.1007/s00421-023-05230-3. Epub 2023 May 28.

    PMID: 37245196BACKGROUND
  • Rolnick N, Licameli N, Moghaddam M, Marquette L, Walter J, Fedorko B, Werner T. Autoregulated and Non-Autoregulated Blood Flow Restriction on Acute Arterial Stiffness. Int J Sports Med. 2024 Jan;45(1):23-32. doi: 10.1055/a-2152-0015. Epub 2023 Aug 10.

    PMID: 37562444BACKGROUND
  • Liu Y, Jiang N, Pang F, Chen T. Resistance Training with Blood Flow Restriction on Vascular Function: A Meta-analysis. Int J Sports Med. 2021 Jun;42(7):577-587. doi: 10.1055/a-1386-4846. Epub 2021 Mar 18.

    PMID: 33735919BACKGROUND
  • Pereira-Neto EA, Lewthwaite H, Boyle T, Johnston K, Bennett H, Williams MT. Effects of exercise training with blood flow restriction on vascular function in adults: a systematic review and meta-analysis. PeerJ. 2021 Jul 7;9:e11554. doi: 10.7717/peerj.11554. eCollection 2021.

    PMID: 34277146BACKGROUND
  • Zhang T, Tian G, Wang X. Effects of Low-Load Blood Flow Restriction Training on Hemodynamic Responses and Vascular Function in Older Adults: A Meta-Analysis. Int J Environ Res Public Health. 2022 May 31;19(11):6750. doi: 10.3390/ijerph19116750.

    PMID: 35682336BACKGROUND
  • Sardeli AV, do Carmo Santos L, Ferreira MLV, Gaspari AF, Rodrigues B, Cavaglieri CR, Chacon-Mikahil MPT. Cardiovascular Responses to Different Resistance Exercise Protocols in Elderly. Int J Sports Med. 2017 Nov;38(12):928-936. doi: 10.1055/s-0043-115737. Epub 2017 Sep 26.

    PMID: 28950398BACKGROUND
  • Dvoretskiy S, Lieblein-Boff JC, Jonnalagadda S, Atherton PJ, Phillips BE, Pereira SL. Exploring the Association between Vascular Dysfunction and Skeletal Muscle Mass, Strength and Function in Healthy Adults: A Systematic Review. Nutrients. 2020 Mar 7;12(3):715. doi: 10.3390/nu12030715.

    PMID: 32156061BACKGROUND
  • Mendonca GV, Pezarat-Correia P, Vaz JR, Silva L, Heffernan KS. Impact of Aging on Endurance and Neuromuscular Physical Performance: The Role of Vascular Senescence. Sports Med. 2017 Apr;47(4):583-598. doi: 10.1007/s40279-016-0596-8.

    PMID: 27459861BACKGROUND

Central Study Contacts

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 fist experimental condition.
Purpose
SUPPORTIVE CARE
Intervention Model
CROSSOVER
Model Details: Parallel group crossover randomized trial
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

September 11, 2024

First Posted

September 19, 2024

Study Start

October 1, 2024

Primary Completion

May 1, 2025

Study Completion

July 1, 2025

Last Updated

October 23, 2024

Record last verified: 2024-10

Data Sharing

IPD Sharing
Will share

Data obtained in this study may be provided to qualified researchers with academic interest in vascular responses to resistance training with blood flow restriction. Data or samples shared will be coded, with no PHI included. Approval of the request and execution of all applicable agreements (i.e. a material transfer agreement) are prerequisites to the sharing of data with the requesting party.

Shared Documents
STUDY PROTOCOL
Time Frame
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