Muscle Hypertrophy
Conditions
Keywords
Blood Flow Restriction
Brief summary
This study aimed to compare the effects of low-load blood flow restriction resistance exercise (BFR-RE) performed to voluntary failure with traditional high-load resistance exercise (HL-RE) and a control condition on biceps brachii muscle hypertrophy, muscle stiffness, and maximal strength in untrained young men. Participants completed an 8-week training program, with exercise performed three times per week. Outcomes were assessed using ultrasound imaging, elastography, and one-repetition maximum (1RM) testing. The study evaluates whether low-load BFR training can produce adaptations comparable to high-load resistance training.
Detailed description
This study was designed to examine the efficacy of low-load blood flow restriction resistance exercise (BFR-RE) performed to voluntary failure compared with traditional high-load resistance exercise (HL-RE) in inducing muscular adaptations in untrained individuals. The experimental framework was structured to isolate the effects of mechanical load and metabolic stress by standardizing the selection of exercises and the training frequency across groups. A controlled, single-blind, repeated-measures design was used, with participants allocated to BFR-RE, HL-RE, or a non-exercising control condition. The intervention period was set at 8 weeks to ensure sufficient exposure for hypertrophic and neuromuscular adaptations, while minimizing potential confounding effects of long-term training variability. The BFR-RE protocol was developed to emphasize metabolic stress through low external loading (30% 1RM), partial vascular occlusion (60% limb occlusion pressure), and sets performed to volitional failure. In contrast, the HL-RE condition was structured to prioritize mechanical tension using moderate-to-high loading (70% 1RM) without vascular restriction. This contrast enables a mechanistic comparison of two distinct hypertrophic stimuli. To reduce acute exercise-induced confounding factors, particularly transient muscle swelling, post-intervention assessments were complemented with a delayed follow-up measurement. This approach was incorporated better to reflect true morphological adaptations rather than short-term physiological responses. The methodological approach integrates imaging-based and performance-based assessments to capture both structural and functional adaptations. The overall design enables evaluation of whether BFR-RE can provide a time-efficient and lower-load alternative to traditional resistance training while maintaining comparable adaptive outcomes.
Interventions
Resistance exercise was performed under partial vascular occlusion using a pneumatic cuff applied to the upper arm. Limb occlusion pressure was individually determined, and exercise was conducted at a relative intensity corresponding to a percentage of one-repetition maximum. Occlusion pressure was maintained during sets and released between exercises. Training load and repetition tempo were standardized and progressively adjusted throughout the intervention period.
BEHAVIORALHigh-Load Resistance Exercise
Participants performed resistance exercise using conventional loading strategies based on a percentage of one-repetition maximum. Training intensity, volume, and progression were standardized across sessions, with loads adjusted periodically according to performance assessments.
Sponsors
Mehmet Akif Ersoy University
Karabuk University
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Masking description
This study employed a single-blind design in which outcome assessors were blinded to group assignment while participants care providers and investigators were not blinded due to the nature of the exercise intervention.
Intervention model description
Participants were assigned to one of three parallel groups: blood flow restriction training group low load resistance training group and control group and all outcomes were assessed pre and post intervention.
Eligibility
Sex/Gender
MALE
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy male participants aged 18-30 years No prior history of structured or specialized resistance training targeting the biceps brachii muscle Normotensive (blood pressure \<140/90 mmHg) Right-handed (to reduce variability related to limb dominance) Willing to provide written informed consent and comply with the study protocol
Exclusion criteria
History of orthopedic injury or musculoskeletal disorder affecting the upper extremities Diagnosis of hypertension (≥140/90 mmHg) or cardiovascular disease Any neurological condition affecting motor performance Current participation in any structured resistance training program Use of medications or supplements known to influence muscle metabolism or performance
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Biceps Brachii Muscle Thickness | Baseline and 8 weeks (post-intervention), with an additional follow-up measurement at 1 week after the intervention | Muscle thickness of the biceps brachii was assessed using ultrasound imaging to evaluate hypertrophic adaptations following the intervention. |
Countries
Turkey (Türkiye)
Outcome results
None listed