Acute Physiological Responses to Twice Daily Blood Flow Restriction Training

Not Applicable

Recruiting

• Conditions: Muscle Weakness; Muscle Damage

• Registration Number: NCT06334224
• Lead Sponsor: Defence Medical Rehabilitation Centre, UK

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2023-11-06
• Status Verified: 2024-03
• Study First Submitted: 2024-03-07
• Study First Submitted QC: 2024-03-19
• Last Update Submitted: 2024-03-19
• Study First Posted: 2024-03-27
• Last Update Posted: 2024-03-27
• Primary Completion: 2024-09
• Study Completion: 2024-09

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 18

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Maximum isometric voluntary contraction of knee extensor muscles	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	Measured using an isokinetic dynamometer

Secondary Outcome Measures

Name	Time	Method
Quadriceps discomfort	Measured immediately after each exercise session	Measured immediately after each exercise session using a 100 mm visual analog scale. A higher score indicates greater levels of discomfort.
Venous blood sampling for markers of exercise induced muscle damage	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	Venous blood samples to measure markers of exercise induced muscle damage. E.g., Creatine Kinase (units/L)
Discomfort caused by the BFR cuff	Measured immediately after each exercise session	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.
Rating of perceived exertion	Measured immediately after each exercise session	Measured using a Borg 0-10 rating of perceived exertion scale. A higher score represents greater levels of exertion.
Delayed onset muscle soreness	Measures collected in the morning on day 1,2,3,4,5,8	Measured using a 100 mm visual analog scale. A higher score indicates greater levels of muscle soreness.
Daily wellness questionnaire	Measures collected in the morning on day 1,2,3,4,5,8	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.
Vastus lateralis muscle thickness	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	Measured using B-Mode ultrasound
Knee joint range of motion	Measures collected in the morning on day 1,2,3,4,5,8	measured using a goniometer
Venous blood sampling for inflammatory markers	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	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).

Trial Locations

Locations (1)

Defence Medical Rehabilitation Centre; 🇬🇧 Loughborough, United Kingdom