Acute Physiological Responses to Twice Daily Blood Flow Restriction Training

Effects of Twice Daily Blood Flow Restriction Training on Muscle Swelling, Markers of Exercise Induced Muscle Damage and Inflammation: A Randomised Control Trial

The Academic Department of Military Rehabilitation (ADMR) is currently conducting a pan-defence, randomised control trial (RCT) investigating the utility of twice daily blood flow restriction training in UK military personnel with persistent knee pain (NCT05719922). Due to logistical confinements, this pan-defence RCT is confined to collecting outcome data pre and post-intervention. Therefore, the acute physiological mechanisms which underpin adaptation will remain unknown.

Consequently, ADMR is undertaking an additional, single centre RCT which will compare the acute physiological responses to low load resistance training with and without the addition of blood flow restriction. Specifically, this study will elucidate the effect of twice daily blood flow restriction training on measures of muscle swelling, muscle damage and inflammation. This data may aid in the optimisation of blood flow restriction exercise prescription within UK Defence Rehabilitation and elsewhere.

Study Overview

• Status: Recruiting
• Conditions: Muscle Weakness; Muscle Damage
• Intervention / Treatment: Other: Low load resistance training; Device: Low load resistance training with blood flow restriction

• Study Type: Interventional
• Enrollment (Estimated): 18
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Peter Ladlow, PhD; Phone Number: 3407 +44 (0)1509 251 500; Email: peter.ladlow100@mod.gov.uk
• Study Contact Backup: Name: Russ Coppack, PhD; Phone Number: 4418 +44 (0)1509 251 500; Email: Russ.Coppack100@mod.gov.uk

Study Locations

• United Kingdom
  • Loughborough, United Kingdom, LE12 5QW
    • Recruiting
    • Defence Medical Rehabilitation Centre
    • Contact: Kieran M Lunt, MSc; Phone Number: 3401 +44(0) 1509 251 500; Email: kieran.lunt103@mod.gov.uk
    • Contact: Peter Ladlow, PhD; Phone Number: 3407 +44(0) 1509 251 500; Email: peter.ladlow100@mod.gov.uk
    • Principal Investigator: Kieran M Lunt, MSc

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 18 - 55 years
• Must not have performed regular lower-limb resistance training for the last 6 months (participants must have performed < 1 lower-limb resistance training session per week over the previous 6 months)
• DMRC Staff member (civilian or service personnel)

Exclusion Criteria:

• Any medical contraindication related to BFR*.
• Any current lower-limb musculoskeletal injury
• Restricted range of movement. i.e. Chronically locked knee or fixed flexion deformity.
• Any physical impairment or co-morbidities (including cardio-vascular disease) precluding the safe participation in the intervention and/or assessment procedures
• Non-musculoskeletal or serious pathological condition (i.e. Inflammatory arthropathy, infection or tumour).
• Use of any medication which may contraindicate the performance of BFR or influence blood biomarkers of EIMD or inflammation.
• Use of any performance enhancing supplements or ergogenic aids such as creatine monohydrate.

• Any individual who is known to be currently pregnant

  *Medical-based Exclusion Criteria (based on clinical contraindications to performing BFR):

• History of cardiovascular disease (hypertension, peripheral vascular disease, thrombosis/embolism, ischaemic heart disease, myocardial infarction).
• History of the following musculoskeletal disorders: rheumatoid arthritis, avascular necrosis or osteonecrosis, severe osteoarthritis.
• History of the following neurological disorders: Peripheral neuropathy, Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, severe traumatic brain injury.
• Varicose veins in the lower-limb.
• Acute viral or bacterial upper or lower respiratory infection at screening.
• Known or suspected lower limb chronic exertional compartment syndrome (tourniquet raises intra-compartmental muscle pressure).
• Postsurgical swelling.
• Surgical insertion of metal components at the position of cuff inflation.
• History of any of the following conditions or disorders not previously listed: diabetes, active cancer.
• History of elevated risk of unexplained fainting or dizzy spells during physical activity/exercise that causes loss of balance
• Increased risk of haemorrhagic stroke, exercise induced rhabdomyolysis.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Low-load resistance training; Twice-daily low load resistance training for four days	Other: Low load resistance training; Leg press and knee extensor exercises. Four sets (30,15,15,15 repetitions) performed at 20% of one repetition maximum.
Experimental: Blood flow restriction training; Twice-daily low load resistance training with blood flow restriction for four days	Device: Low load resistance training with blood flow restriction; The intervention involves placing a pneumatic tourniquet system over the proximal thigh. The cuff is inflated to 80% of limb occlusion pressure during lower limb strengthening exercises. These exercises include leg press and knee extensor exercises. Four sets (30,15,15,15 repetitions) performed at 20% of one repetition maximum.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum isometric voluntary contraction of knee extensor muscles	Measured using an isokinetic dynamometer	Measures collected in the morning on day 1,2,3,4,5,8. Measures also performed immediately before and 30 seconds after exercise on day 1 and 4

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vastus lateralis muscle thickness	Measured using B-Mode ultrasound	Measures collected in the morning on day 1,2,3,4,5,8. Measures also performed before, 3 min after and 4 hours after exercise on day 1 and 4
Venous blood sampling for markers of exercise induced muscle damage	Venous blood samples to measure markers of exercise induced muscle damage. E.g., Creatine Kinase (units/L)	Measures collected in the morning on day 1,2,4,5,8. Measures also performed before, 10 min after and 4 hours after exercise on day 1
Delayed onset muscle soreness	Measured using a 100 mm visual analog scale. A higher score indicates greater levels of muscle soreness.	Measures collected in the morning on day 1,2,3,4,5,8
Quadriceps discomfort	Measured immediately after each exercise session using a 100 mm visual analog scale. A higher score indicates greater levels of discomfort.	Measured immediately after each exercise session
Discomfort caused by the BFR cuff	Measured in the intervention group immediately after each exercise session using a 100 mm visual analog scale. A higher score indicates greater levels of discomfort.	Measured immediately after each exercise session
Rating of perceived exertion	Measured using a Borg 0-10 rating of perceived exertion scale. A higher score represents greater levels of exertion.	Measured immediately after each exercise session
Knee joint range of motion	measured using a goniometer	Measures collected in the morning on day 1,2,3,4,5,8
Daily wellness questionnaire	UK Defence Rehabilitation daily wellness questionnaire. This questionnaire asks participants to rate their: fatigue, muscle soreness, sleep quality, stress levels and mood on a 1-5 Likert scale.	Measures collected in the morning on day 1,2,3,4,5,8
Venous blood sampling for inflammatory markers	Venous blood samples to measure markers of inflammation. E.g., Interleukin-6 (pg/ml), Tumour necrosis factor alpha (pg/mL) and vascular endothelial growth factor (pg/mL).	Measures collected in the morning on day 1,2,4,5,8. Measures also performed before, 10 min after and 4 hours after exercise on day 1

Collaborators and Investigators

• Sponsor: Defence Medical Rehabilitation Centre, UK
• Collaborators: University of Bath
• Investigators: Study Chair: Alexander Bennett, PhD, Defence Medical Rehabilitation Centre

Study record dates

Study Major Dates

• Study Start (Actual): November 6, 2023
• Primary Completion (Estimated): September 1, 2024
• Study Completion (Estimated): September 1, 2024

Study Registration Dates

• First Submitted: March 7, 2024
• First Submitted That Met QC Criteria: March 19, 2024
• First Posted (Actual): March 27, 2024

Study Record Updates

• Last Update Posted (Actual): March 27, 2024
• Last Update Submitted That Met QC Criteria: March 19, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Keywords: occlusion; resistance training; blood flow restriction; exercise induced muscle damage; muscle swelling
• Additional Relevant MeSH Terms: Pathologic Processes; Nervous System Diseases; Neurologic Manifestations; Musculoskeletal Diseases; Muscular Diseases; Neuromuscular Manifestations; Muscle Weakness
• Other Study ID Numbers: 2242/MODREC/23

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Anonymised participant data will be made available upon reasonable request to the chief investigator
• IPD Sharing Time Frame: Upon completion of the dissemination of research findings (i.e., publications and conference proceedings)
• IPD Sharing Access Criteria: Most data will be openly available, but due to privacy concerns, some data regarding participants are available only to bona fide researchers working on a related project, subject to the completion of a non-disclosure agreement
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; CSR

Drug and device information, study documents

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