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.

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.

Anonymised participant data will be made available upon reasonable request to the chief investigator

Upon completion of the dissemination of research findings (i.e., publications and conference proceedings)

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

Due to the nature of the intervention, it is not possible to blind participants or outcome assessors to the treatment allocation. There is also no effective sham condition available. This is a common limitation within all blood flow restriction training research.