Low-intensity training performed with occlusion bands provides a unique experience for those interested in rapid muscle growth in a short period of time. Using blood flow restriction training, it is possible to achieve noticeable results using intensities as low as 20 percent. Muscle hypertrophy can be observed in as little as three weeks using blood flow restriction training.1
The effectiveness of blood flow restriction training is based on how your body responds to stress. When blood is allowed to enter a target muscle and prevented from leaving, the cells will begin to swell. The swelling of the cells signals “danger” to your muscles. In response, your muscle lays down new fibers and grows bigger to compensate for the extra load you’re placing on it. BFR training also increases the buildup of lactic acid in the muscle. Lactic acid stimulates IGF-1 production as well as protein synthesis, thereby increasing growth.
The typical BFR training workout calls for three to five sets of a particular exercise until volitional muscle fatigue is reached. The metabolic buildup that occurs with this type of training causes a rise in the production of human growth hormone that is equal to or greater than the levels that occur when using regular weight training at higher intensities.
Who Can Use BFR?
BFR training is ideal for :
- Those who are unable to tolerate high loads during weight training due to joint pain
- Those who are undergoing cardiac rehabilitation or those recovering from surgery
- Athletes who need active recovery training sessions
- Astronauts who have recently returned from space
- Women who want to gain muscle and strength but don’t want to lift heavy weight
- Men looking to break through strength and size plateaus
Single-joint resistance (weight training using a single limb) performed along with blood flow restriction has the ability to cause a significant increase in muscle size and joint strength. Although single-joint training has been proven extremely effective, multi-joint training and training for trunk muscles may not show the same results.
A study was performed using 10 young men as the subjects. The men were divided into two groups. One group performed BFR training while the other group did not. Researchers gauged how the men responded to chest exercises without BFR and upper-arm exercises with BFR. Both groups performed these exercises (bench presses) at 30 percent of one rep for four sets (75 reps total) twice a day, six days a week for two weeks. During the exercise session, the subjects in the BFR group were given elastic cuffs to place around their upper arms. The cuff tightness was increased over the course of the test period. The muscle thickness of the triceps and pectoral muscles were measured before and after each session along with levels of metabolic buildup. Two weeks of training increased the strength of the BFR group by eight percent for the triceps and 16 percent for the pectoral muscles. The non-BFR group, by comparison, showed very little increase. The conclusive results of the test suggested that bench pressing with blood flow restriction training can lead to a significant increase in muscle size and strength for the upper arm and chest muscles.3
Another study was designed to evaluate the training techniques most likely to provide the greatest benefit for those using BFR training. The primary focus of the study was to compare the effects of low-intensity endurance training with blood flow restriction of some type. All subjects were required to have certain baseline characteristics to ensure rapid muscle growth or hypertrophy. The studies included MRI imaging for most of the subjects, except for two who were evaluated using ultrasound. The results showed that, when performed along with resistance training, blood flow restriction training results in greater gains in strength and muscle growth over blood flow restricted walking. In addition, low-intensity exercise with blood flow restriction training two to three days per week was found to to be more effective than four or five times per week. With this type of exercise, more is not necessarily better.4
Test results for another study were similar. Thirty young men were split into groups of ten. One group performed high-intensity training while another group performed low-intensity training with blood flow restriction. The third group was the control group. During the exercise sessions, the blood flow restriction group wore elastic cuffs around the arms as close to the shoulder as reasonably possible. The strength of each group performing these exercises was measured prior to and three days following the final training session. The training volume was approximately the same between the two groups. The two training groups demonstrated increased strength for bench press exercises with a greater increase in muscle growth for the BFR training group.5
Forty men between the ages of 22 and 32 years of age were selected to participate in a study to evaluate muscle adaptation to the stresses of blood flow restriction and high-intensity resistance training. The men were split into four groups of 10 men each. Group one performed high-intensity resistance training. Group two performed low-intensity resistance training with blood flow restriction. Group three combined high-intensity resistance training with blood flow restriction. Group four, the control group, performed no training at all.
Three groups performed bench presses three times a day for six weeks. During the low-intensity blood flow restriction sessions, the subjects of the test wore pressure bands on their arms. Groups one and two showed similar increases in muscle strength, while the third group was slightly lower. Elbow extension increased in the high-intensity resistance training group but remained the same for the blood flow restriction training group.
At the end of the training period, the group that performed BFR training demonstrated that the technique can be more effective when combined with high-intensity resistance training.6
This study involved testing the effects of low-intensity resistance training with blood flow restriction on muscle size and muscle strength. Ten young men performed dumbbell exercises at 30 percent of their one rep max at a rate of four sets of 75 reps each, three times a day for six weeks. One arm was chosen exclusively for concentric (lifting) BFR exercise, while the other arm performed eccentric (lowering) BFR exercise at the same load level.
The arm used for concentric exercises increased in muscle thickness at a rate greater than the arm used for eccentric exercises alone. Immediately following the exercise, the muscle thickness was measured and found to be significantly greater. Test results showed that concentric blood flow restriction training can increase muscle size more than eccentric blood flow restriction training. This finding may be an important factor in promoting rapid muscle growth with blood flow restriction training.7
In the last decade, muscle training performed using a combination of low external loads and partial blood flow restriction training to the limb being exercised has become more popular as a way to gain muscle strength and increased muscle mass.
Although the cellular mechanisms responsible for muscle growth are not fully understood, it has been shown that weeks of high-frequency, low-intensity muscle exercise with blood flow restriction causes an increase in muscle strength along with muscle size.
Ten male subjects, averaging 23 years of age, performed four sets of leg extensions to failure with blood flow restriction applied to the thigh. Eight men of the same age as those in the control group performed training sessions without blood flow restriction. Muscle biopsies were obtained at the start, after eight days and at the end of the 10-day training session. This study was the first to show that short-term low-load resistance training performed with BFR can lead to an increase in muscle cell growth in human skeletal muscle. The same was found to be true for those who performed squats and bench press exercises while using BFR. Chest and upper arm girths were significantly increased during the test phase.8,9
BFR is Safe and Effective
In the 21st century, different types of training are being tested and found helpful in causing the rapid growth of muscle. Because blood flow restriction training uses a cuff placed on the limb to be trained, it is often thought it can only be used on arms and legs. However, the research clearly suggests it has an effect on the distal musculature as well such as the chest, back, shoulders, calves, etc.
Blood flow restriction training limits blood flow from the the veins to the heart. Keep in mind that BFR does not prevent blood from entering the muscle. It only slows blood from leaving the muscle. Studies have shown that blood flow restriction training can help increase bone mass and muscle growth when used alone or with low-load intensity training.
Unlike the traditional weight lifting training methods, blood flow restriction training can be used for both trained and untrained lifters and strength. Even simple walking with BFR is beneficial for those unable to exercise more actively due to injury or old age.
One study performed with the BFR Bands had 10 well trained males perform BFR walk training for 3 weeks. What the study found was astonishing. Their VO2 max went up, their 1.5 mile run times decreased, and thigh muscle size increased – all from simply walking!10
When properly executed, blood flow restriction training is a safe and extremely effective form of exercise. When applying the elastic wraps, the user should place the wraps at a perceived tightness of approximately seven out of ten. No pain should be felt at this point. If any pain is felt before exercise begins, the wraps are too tight. If any tingling or numbness is felt at any point, the bands should be loosened.
As always, those interested in new exercise regimens should speak with a healthcare provider before beginning anything new. BFR may be contraindicated for pregnant women and those suffering from varicose veins, high blood pressure or heart problems, DVT, diabetes, or any other circulatory disease.
Low-intensity exercises, when combined with blood flow restriction training, has a positive effect on the secretion of growth hormones and muscle hypertrophy. Studies have shown that this exercise technique can also be used to help those recover from surgery. When the training was implemented from the third to the 14th day, muscle atrophy was decreased significantly.
Athletes who perform training with BFR will run out of energy much more quickly than with other forms of training. Err on the side of less weight when you are first starting out until you find your “sweet spot.” Less weight is necessary when using BFR to achieve the same results, with recommended weights around 20% of your 1 repetition maximum or less.
Blood flow restriction training is most effective when you push yourself to the point of muscle failure. When you work to failure, you amplify the effects of BFR training, yielding better results in less time.
Although many workout magazines and training websites try to repaint old methods as “breakthrough” techniques for building muscle faster than ever before, they are usually just generic ideas that provide insignificant progress at best.
When used alone, blood flow restriction training can have similar effects on the body as traditional weight training. However, when combined with strength training, it can increase your results many times over.11