Low-Load BFR vs. High-Load Training on Biceps Hypertrophy
Bayesian Comparison of Low-Load Blood Flow Restriction and High-Load Resistance Exercise on Biceps Brachii Muscle Hypertrophy in Untrained Men
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.
Study Overview
Status
Conditions
Intervention / Treatment
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.
Study Type
Enrollment (Actual)
Phase
- Not Applicable
Contacts and Locations
Study Locations
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Karabük Province
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Karabük, Karabük Province, Turkey (Türkiye), 78050
- Karabük University Hasan Dogan Faculty of Sport Sciences
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Participation Criteria
Eligibility Criteria
Ages Eligible for Study
- Adult
Accepts Healthy Volunteers
Description
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
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Treatment
- Allocation: Non-Randomized
- Interventional Model: Parallel Assignment
- Masking: Single
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
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Experimental: BFR-RE
Participants performed low-load resistance exercise with blood flow restriction using 30% of one-repetition maximum (1RM) and 60% limb occlusion pressure.
Exercises were performed to voluntary failure, three times per week for 8 weeks.
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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.
Other Names:
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Active Comparator: HL-RE
Participants performed traditional high-load resistance exercise at 70% of one-repetition maximum (1RM) without blood flow restriction, three times per week for 8 weeks.
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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.
Other Names:
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No Intervention: Control
Participants did not engage in any structured resistance training program and continued their normal daily activities throughout the 8-week study period.
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What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Biceps Brachii Muscle Thickness
Time Frame: Baseline and 8 weeks (post-intervention), with an additional follow-up measurement at 1 week after the intervention
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Muscle thickness of the biceps brachii was assessed using ultrasound imaging to evaluate hypertrophic adaptations following the intervention.
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Baseline and 8 weeks (post-intervention), with an additional follow-up measurement at 1 week after the intervention
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Collaborators and Investigators
Sponsor
Collaborators
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Other Study ID Numbers
- Mehmet Akif Ersoy Universitesi
- BFR_HLRE_UntrainedMen (Registry Identifier: Bayesian Comparison of Low-Load Blood Flow Restriction and High-Load Resistance Exercise on Biceps Brachii Muscle Hyper)
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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