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Muscle DamageNCT05037942

The Effects of Restriction Pressure on Muscle Damage Responses to Blood Flow Restriction Exercise

A study testing Blood flow restriction at 40% limb occlusion pressure and Blood flow restriction at 80% limb occlusion pressure in people with Muscle Damage and Muscle Soreness, run by University of Surrey at 1 site in United Kingdom.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Blood flow restriction (BFR) exercise involves the application of a constriction device to the limbs to restrict muscle blood flow during exercise. In recent years, BFR has become increasingly popular due to its additive effects on low-load resistance training, often promoting greater increases in muscle strength and… Read more about this study

Who is it for?
Ages 18 to 45 yearsHealthy volunteers can take part
Conditions the study is for
Muscle Damage, Muscle Soreness, Muscle Strength
What is being tested?
Blood flow restriction at 40% limb occlusion pressure and Blood flow restriction at 80% limb occlusion pressure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
34 participants
Where
1 siteUnited Kingdom
Study dates
29 Nov 2021to 28 Jun 2022
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Recreationally active (defined as performing ≥ 150 minutes of moderate-intensity or ≥ 75 minutes of vigorous-intensity exercise per week for the past 6 months)
  • Resistance-untrained (defined as performing less than 2 resistance exercise sessions per week for the past 6 months)

Who cannot join

  • Any history of cardiovascular (including hypertension [diastolic > 90 and/or systolic blood pressure > 140 mmHg] and peripheral arterial vascular disease), metabolic, respiratory (including severe asthma), haematological (including deep vein thrombosis and pulmonary embolism), neurological, gastrointestinal, kidney, liver, or musculoskeletal disease
  • Current or previous musculoskeletal injury that may be aggravated by exercise
  • Current smoker
  • Recently used prescribed anti-inflammatory medication within the previous 1 month
  • Self-reported or diagnosed menstrual irregularities within ≥ 3 months prior to recruitment
  • Currently pregnant

Trial locations and contacts

1 site in 1 country.

United Kingdom1 site
  • University of Surrey

    Guildford, Surrey, GU2 7XH

Other trials in United Kingdom

About this study

Official title: The Influence of Restriction Pressure on Indices of Exercise-Induced Muscle Damage Following Low-Load Blood Flow-Restricted Resistance Exercise: A Randomised Controlled Trial in Healthy Adults

Blood flow restriction (BFR) exercise involves the application of a constriction device to the limbs to restrict muscle blood flow during exercise. In recent years, BFR has become increasingly popular due to its additive effects on low-load resistance training, often promoting greater increases in muscle strength and size compared to similar resistance training without BFR. However, like other exercise, it is possible that BFR exercise can cause exercise-induced muscle damage (EIMD) that results in short-term reductions in muscle function and increased muscle soreness and swelling. One major variable that may influence the onset of EIMD is the restriction pressure used to restrict blood flow; however, the influence of restriction pressure on resistance EIMD is unclear.

The purpose of this study is to investigate effects of two different restriction pressures (low and high) on EIMD responses to a bout of low-load BFR resistance exercise in a sample of healthy, active adults. It is hypothesised that a higher restriction pressure will result in increased EIMD compared to a lower restriction pressure. To test this hypothesis, participants will perform a lower-body exercise protocol with and without BFR, and several markers of EIMD will be assessed before and immediately, 24, 48, and 72 hours after the exercise.

Read the detailed description

Following screening for the inclusion and exclusion criteria of the study, eligible participants will be fully informed of the study purposes and procedures and written consent will be acquired. During this study, participants will be randomly allocated into one of two experimental groups, with each group performing blood flow-restricted knee extension exercise with one leg and the same exercise protocol without BFR with the contralateral leg. Experimental groups will be differentiated by the tourniquet pressure used during the BFR condition. Several indirect markers of EIMD will be assessed at baseline and 24, 48, and 72 hours after the exercise bout. Additional neuromuscular assessments will be performed immediately post-exercise to provide insight into the fatiguability of the exercise protocol.

Participants will be required to attend the laboratory on five separate occasions: one visit for screening, assessment of limb occlusion pressure (i.e., the lowest pressure required to occlude blood flow to the limb), and familiarisation of the exercise protocol and neuromuscular assessments, one visit for completion of the exercise protocol and baseline/post-exercise tests, and three follow-up visits. All participants will be asked to refrain from alcohol and exercise from 24 hours prior to the exercise trial up to their final visit. The consumption of any pain-relieving medications (e.g., anti-inflammatory drugs) and undergoing of any muscle damage treatments (e.g., massage) will be prohibited throughout the study. To minimise the effects of pre-exercise feeding on the outcome measures, visits will be scheduled for the morning and participants will attend the lab following an overnight fast of a minimum of 10 hours, although water may be consumed ad libitum. All post-exercise measures will be collected at the same time of day ± 1 hours.

Being tested
Blood flow restriction at 40% limb occlusion pressure, Blood flow restriction at 80% limb occlusion pressure
Keywords
Muscle Damage, Muscle Soreness, Muscle Strength, Blood Flow Restriction
Medical subject headings
Myalgia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Blood flow restriction at 40% limb occlusion pressureOther

    Also called Vascular restriction, Vascular occlusion, Venous restriction

    A 13-cm-wide pneumatic cuff will be applied to the most proximal portion of the chosen thigh (as determined by randomisation), immediately distal to the inguinal fold, prior to a bout of lower-body resistance exercise. The cuff will be inflated to 40% of limb occlusion pressure pressure and will remain inflated throughout the exercise (total occlusion time: ~5 mins).

  • Blood flow restriction at 80% limb occlusion pressureOther

    Also called Vascular restriction, Vascular occlusion, Venous restriction

    A 13-cm-wide pneumatic cuff will be applied to the most proximal portion of the chosen thigh (as determined by randomisation), immediately distal to the inguinal fold, prior to a bout of lower-body resistance exercise. The cuff will be inflated to 80% of limb occlusion pressure pressure and will remain inflated throughout the exercise (total occlusion time: ~5 mins).

Study groups in NCT05037942
Study groupRoleWhat they receive
Blood flow-restricted exercise at 40% limb occlusion pressure (BFR-40)ExperimentalParticipants in BFR-40 will perform a lower-body exercise protocol under BFR set to 40% of the participants' relative limb occlusion pressure.
Receives: Other: Blood flow restriction at 40% limb occlusion pressure
Blood flow-restricted exercise at 80% limb occlusion pressure (BFR-80)ExperimentalParticipants in BFR-80 will perform the same lower-body BFR exercise protocol as BFR-40; however, the occlusion pressure will be set to 80% of the participants' relative limb occlusion pressure.
Receives: Other: Blood flow restriction at 80% limb occlusion pressure
Control for BFR-40No interventionParticipants randomised to BFR-40 will perform the same exercise protocol without BFR with the contralateral leg.
Control for BFR-80No interventionParticipants randomised to BFR-80 will perform the same exercise protocol without BFR with the contralateral leg.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Mean change in maximal voluntary isometric force of the knee extensors from pre-intervention up to 72 hours post-intervention

    The change in the maximum amount of voluntary isometric force produced by the knee extensors, assessed via a series of maximal voluntary contractions performed at 90 degrees of knee flexion (extension = 0 degrees).

    Measured: Immediately pre-intervention, immediately post-intervention, 24 hours post-intervention, 48 hours post-intervention, 72 hours post-intervention

Secondary outcomes (5)
  1. Mean change in the joint angle-torque curve of the knee extensors from pre-intervention up to 72 hours post-intervention

    The change in the joint angle-torque curve of the knee extensors, assessed using a series of maximal isokinetic contractions performed from 90 to 0 degrees of knee flexion at an angular velocity of 45 degrees per second.

    Measured: Immediately pre-intervention, immediately post-intervention, 24 hours post-intervention, 48 hours post-intervention, 72 hours post-intervention

  2. Mean change in plasma creatine kinase from pre-intervention up to 72 hours post-intervention

    The change in plasma creatine kinase assessed via a commercially-available assay kit.

    Measured: Immediately pre-intervention, 24 hours post-intervention, 48 hours post-intervention, 72 hours post-intervention

  3. Mean change in pain-free range of motion of the knee extensors from pre-intervention up to 72 hours post-intervention

    "Pain-free range of motion of the knee extensors" describes the degree of passive knee flexion the participant can achieve until they reach a point of self-perceived soreness. The assessment involves the investigator progressively moving the shank of the participant into further knee flexion until the participant experiences noticeable discomfort, at which the knee joint angle will be measured using a goniometer.

    Measured: Immediately pre-intervention, 24 hours post-intervention, 48 hours post-intervention, 72 hours post-intervention

  4. Mean change in muscle thickness of the rectus femoris and vastus lateralis from pre-intervention up to 72 hours post-intervention

    The change in muscle thickness of the rectus femoris and vastus lateralis when measured using B-mode ultrasound at 50 percent total femur length. Muscle thickness will be defined as the mean perpendicular distance between the deep and superficial aponeuroses at the proximal, central, and distal portions of the acquired images.

    Measured: Immediately pre-intervention, 24 hours post-intervention, 48 hours post-intervention, 72 hours post-intervention

  5. Mean change in perceived muscle soreness from pre-intervention up to 72 hours post-intervention

    The change in perceived lower-body muscle soreness when assessed at rest and during voluntary flexion and extension of the knee. Soreness at rest and during motion will be quantified separately using a 100 mm visual analogue scale titled "Visual Analogue Scale for Muscle Soreness". Participants will be asked to mark their perceived soreness at any point along a horizonal line ranging from 0 mm (no soreness at all) to 100 mm (most soreness ever experienced). Scores will be rounded to the nearest 1 mm.

    Measured: Immediately pre-intervention, 24 hours post-intervention, 48 hours post-intervention, 72 hours post-intervention

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Sep 2021
  2. Study start29 Nov 2021
  3. Primary completion28 Jun 2022
  4. Study completion28 Jun 2022

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Other
Allocation
Randomised
Intervention model
Parallel groups
Model description
The study uses a within-between, unilateral design, in which participants will be randomly allocated into one of two experimental groups using a stratified random allocation technique. Each group will perform blood flow-restricted exercise with one leg and the same exercise protocol without BFR with the contralateral leg. Experimental groups will be differentiated by the tourniquet pressure used during the BFR condition: i) tourniquet pressure set to 40% of limb occlusion pressure or ii) tourniquet pressure set to 80% of limb occlusion pressure. Legs will be counterbalanced such that the BFR and control conditions in each study group contain an equal number of dominant and non-dominant legs. This study design allows comparison between the two experimental conditions (i.e., 40% vs. 80% limb occlusion pressure), while allowing participants to serve as their own control condition.
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
34 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05037942
Sponsor's protocol ID
FHMS 20-21 151 EGA
Status last verified
Dec 2023
First submitted
31 Aug 2021
Last updated
26 Dec 2023
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: Data spreadsheet will be available upon request from the principle investigator.

Publications

  • Patterson SD, Hughes L, Warmington S, Burr J, Scott BR, Owens J, Abe T, Nielsen JL, Libardi CA, Laurentino G, Neto GR, Brandner C, Martin-Hernandez J, Loenneke J. Blood Flow Restriction Exercise: Considerations of Methodology, Application, and Safety. Front Physiol. 2019 May 15;10:533. doi: 10.3389/fphys.2019.00533. eCollection 2019.

    PubMed 31156448
  • Lixandrao ME, Ugrinowitsch C, Berton R, Vechin FC, Conceicao MS, Damas F, Libardi CA, Roschel H. Magnitude of Muscle Strength and Mass Adaptations Between High-Load Resistance Training Versus Low-Load Resistance Training Associated with Blood-Flow Restriction: A Systematic Review and Meta-Analysis. Sports Med. 2018 Feb;48(2):361-378. doi: 10.1007/s40279-017-0795-y.

    PubMed 29043659
  • de Queiros VS, Dos Santos IK, Almeida-Neto PF, Dantas M, de Franca IM, Vieira WHB, Neto GR, Dantas PMS, Cabral BGAT. Effect of resistance training with blood flow restriction on muscle damage markers in adults: A systematic review. PLoS One. 2021 Jun 18;16(6):e0253521. doi: 10.1371/journal.pone.0253521. eCollection 2021.

    PubMed 34143837
  • Hyldahl RD, Hubal MJ. Lengthening our perspective: morphological, cellular, and molecular responses to eccentric exercise. Muscle Nerve. 2014 Feb;49(2):155-70. doi: 10.1002/mus.24077. Epub 2013 Dec 3.

    PubMed 24030935

Questions about this trial

What is this clinical trial studying?

A study testing Blood flow restriction at 40% limb occlusion pressure and Blood flow restriction at 80% limb occlusion pressure in people with Muscle Damage and Muscle Soreness, run by University of Surrey at 1 site in United Kingdom.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 26 Dec 2023. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Mean change in maximal voluntary isometric force of the knee extensors from pre-intervention up to 72 hours post-intervention (time frame: Immediately pre-intervention, immediately post-intervention, 24 hours post-intervention, 48 hours post-intervention, 72 hours post-intervention). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05037942, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Dec 2023.

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