Randomized Controlled Trial
The Effects of Blood Flow Restriction Training on the Muscles Before (Proximal), After (Distal), and Opposite (Contralateral) the BFR Cuff Placement
LayMed Simplified Version
Adding BFR to low-weight resistance training significantly increases muscle size, strength and endurance in the muscles before and after the site of the BFR cuff placement (i.e. if the BFR cuff is placed on the upper thigh, it not only boosts gains in all the upper and lower leg muscles below the cuff, but also in the glutes and other muscles above the cuff). It also increases size, strength and endurance gains in the same muscles on the opposite limb, even if that limb doesnāt have a BFR cuff on it, indicating a crossover or whole-body effect.
BLOOD FLOW RESTRICTION TRAINING:
BFR training involves doing exercises (usually with relatively light weight) while partially restricting blood flow to and from the target muscles using an inflatable cuff at pressures that are based on a percentage of the user’s blood pressure.
This method has multiple proven benefits (including increased muscle size, strength, and endurance), and is particularly useful for people who still want to gain the benefits of high-load exercises without putting too much strain on their joints or tissues, since doing low-weight exercises with BFR has been shown to provide the same or greater gains as high-load exercises.
26 people participated in this trial (all healthy recreational-level athletes between the ages of 20 and 40, with a mix of male and female participants), and were randomly split into two groups:
- BFR Group: Went through a low-weight leg training program with BFR on one leg
- Control Group: Went through the same low-weight leg training program with no BFR
The training program included 2 workout sessions per week, at least 48 hours apart, for 6 weeks. Each session included 4 sets of the following exercises: supineĀ straight-leg raises, side-lying hip abduction, leg extensions, and standing leg curls. Set 1 was performed to 30 reps, with the remaining sets to 15 reps, with 30 second rests between sets, always using 30% of the participantās 1-rep max.
The BFR group performed the exercises with a 4-inch wide BFR cuff placed on the upper thigh of one leg, inflated to achieve 80% AOPĀ for each participant continuously throughout each workout session.
Before and after the 6 week program, researchers measured the size (circumference) of the leg muscles below and above the cuff placement, and took multiple measurements of strength and endurance for those muscles as well.
- 7X more growth in the muscles below the cuff (2.8% vs 0.4%)
- 4.4X more growth in the leg muscles above the cuff (3.5% vs 0.8%)
- 3.7X more strength increase in the quads (11% vs 3%)
- 2.5X more endurance increase in the quads (15% vs 6%)
- 2.2X more strength increase in the hamstrings (11% vs 5%)
- 2X more endurance increase in the hamstrings (27% vs 14%)
- 1.7X more strength increase in hip abduction (46% vs 27%)
- 1.4X more strength increase in hip extension (60% vs 42%)
- 1.8X more strength increase in the calf muscles (33% vs 18%)
- 7X more endurance increase in the calf muscles (28% vs 4%)
- 3X more growth in the muscles below the cuff (1.2% vs 0.4%)
- 2.9X more growth in the leg muscles above the cuff (2.3% vs 0.8%)
- 2.6X more strength increase in the quads (8% vs 3%)
- 1.3X more endurance increase in the quads (8% vs 6%)
- 2X more strength increase in the hamstrings (10% vs 5%)
- 1.6X more endurance increase in the hamstrings (22% vs 14%)
- 1.4X more strength increase in hip abduction (37% vs 27%)
- 1.2X more strength increase in hip extension (49% vs 42%)
- 1.4X more strength increase in the calf muscles (26% vs 18%)
- 4X more endurance increase in the calf muscles (16% vs 4%)
Disclaimer: This simplified version is LayMedās own interpretation of the original articleās text, and may or may not accurately reflect the beliefs, views, or findings of the authors. The article was published in January 2023 inĀ Sports Health, and the copyright is owned by the authors.