How to put on muscle: Why less might be more.

Seven of the 9 (78%) studies noted significant increases in strength associated with BFR training, whilst 4 out of 8 (50%) reported significant increases in muscle size.

Blood flow restriction (BFR) training is a relatively new training method, but it has quickly gained popularity among athletes and fitness enthusiasts alike. This is because BFR has been shown to be very effective at increasing muscle strength and size, even when using light weights.

For those not familiar with this form of training, it is a versatile and portable way of maintaining the consistency of a resistance training programme on the go. BFR involves restricting blood flow to the muscles during exercise. This is done by wrapping a cuff around the upper arm or thigh. The cuff is tightened to a certain pressure, which reduces blood flow to the muscles by about 40-80%. The exact mechanisms by which BFR produces its effects are not fully understood, but it is thought to work by increasing the production of growth hormone and other anabolic hormones. BFR is also thought to increase the recruitment of muscle fibers and to promote muscle hypertrophy.

Research has shown that BFR can produce similar results to traditional resistance training, but with much lower training loads. This makes it not only attractive to those who are new to exercise, significant health conditions, or who have injuries or joint issues that limit their ability to tolerate heavy weights but also those who travel freuently without easy access to fully stocked gyms.

A recent systematic review analysing 250 athletes demonstrated the encouraging effects of BFR training, even in trained individuals. Across the range of studies they reviewed, the length of the training programme ranged from 8 days - 8 weeks and the frequency of sessions from 1 to 4 per week. Seven of the 9 (78%) studies noted significant increases in strength associated with BFR training, whilst 4 out of 8 (50%) reported significant increases in muscle size. The review demonstrated that BFR training has the potential to increase strength and performance as part of a resistance training programme in althetes.

Typically training with BFR requires less than 20% of 1 repetition max in comparison to the 75-85% for traditional heavy load resistance training. Those looking to minimise the load or force through the lower back or specific joint injuries may thus benefit from the lower load required to stimulate similar gains, as would frequent travellers looking for an easy and time efficient way to maintain their training programme whilst travelling. People with cancer, a history of heart, circulatory and clotting issues, or those who are pregnant should not use blood flow restriction training.