What is blood flow restriction training?

The History of Blood Flow Restriction Training

Blood flow restriction training (BFR) has received a considerable amount of attention within the scientific literature over the last two decades. However to understand its origin story, you will need to go back to Japan, 1966. A high school student named Yoshiaki Sato (pictured below) conceived the idea whilst attending a Buddhist memorial service. A fitness enthusiast, Sato noticed that his legs went numb while sitting in a traditional Japanese posture (straight back while kneeling on the floor). While massaging his calf muscle, he noticed a swelling and discomfort that resembled the sensation he experienced following strenuous exercise. Sato believed the swelling he was experiencing in his legs was attributed to a reduction in blood flow (specifically venous return) and may have the capacity to trigger a muscle to adapt, in much the same way as resistance exercise. Using rubber tubing from a bike to partially restrict blood flow to his extremities, Sato began decades of experimentation and research to fine tune his process. This type of training was called KAATSU training (translating to "added pressure"), and in 1983 Sato's methods became available to the general public (Sato, 2005).

Modern Day BFR Training

Fast forward 37 years to the current day, and the concepts of KAATSU and blood flow restriction are becoming common practice in many different fields of musculoskeletal health. A simple PubMed search will return hundreds of peer-reviewed research papers conducted all over the globe, while dozens of products of varying shapes and sizes exist on the market with the sole purpose of restricting blood flow during exercise. The proposed benefits of blood flow restriction training have been observed in many populations from elite athletes to elderly fall victims. This technology has been applied in a vast number of different environments including sports injury rehabilitation, high-performance training, military operations, and even outer space travel! So why has blood flow restriction training gained such popularity over the past 20 years, and how does it really work?

What is Blood Flow Restriction Training?

Blood flow restriction training is typically used in combination with low-intensity resistance exercise or cardiovascular training. It involves the partial or complete occlusion of blood flow to the working muscles via a pneumatic cuff device or restrictive straps. By restricting blood flow in this way, the amount of oxygen that is available to the working muscle is reduced, thus creating a more stressful environment. The reduction in oxygen creates a state of hypoxia within the muscle, allowing users to train at remarkably low intensities and achieve comparable training results as traditional resistance training methods.

 

Does it work?

While BFR was conceived as a passive strategy, it is most commonly used to increase muscle mass and strength in combination with low intensity resistance training. Current guidelines from the American College of Sports Medicine suggest that in order to increase muscle mass and strength an individual is required to train 2 to 3 days per week at 70% of a 1 repetition maximum (1RM). However, when combined with BFR, significant increases in muscle mass and strength have been achieved with a training intensity as little as 20% 1RM (Takarada et al. 2002). Early research was able to achieve a 10% increase in strength and a 5% increase in thigh muscle mass with only 5x2 min bouts of treadmill walking when combined with BFR (Abe et al. 2006). The benefits of BFR training also likely apply to tendons, bones and the cardiorespiratory system. I will explain more about the different benefits of BFR training in a future blog.

Why is it important?

Utilizing BFR allows you to achieve comparable training results using a remarkably low intensity, as you otherwise would be able achieve training at a high intensity. This means that people who are unable to lift heavy weights, or run a marathon, can still reap the benefits of intense exercise. It is therefore not surprising that BFR training is most commonly used in injury rehabilitation, and has considerable implications for elderly individuals. BFR training is also starting to infiltrate the world of elite sport where it is being used to optimize sports performance and enhance muscle recovery.

What's next?

In this series of blogs we will explore how to use BFR training safely and effectively. We will also look at how it is being used to improve performance, rehabilitate injury and treat disease around the world.

References:

1. Sato, Y., The history and future of KAATSU training. International Journal of Kaatsu Training Research, 2005. 1: p. 1-5. https://www.jstage.jst.go.jp/article/ijktr/1/1/1_1_1/_article
2. Takarada, Y., et al., Effect of resistance exercise combined with vascular occlusion on muscle function in athletes, European Journal of Applied Physiology, 2002. 86 (4): p. 308-14. https://www.ncbi.nlm.nih.gov/pubmed/11990743
3. Abe, T., et al., Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training. Journal of Applied Physiology, 2006. 100: 1460-1466. https://pubmed.ncbi.nlm.nih.gov/16339340/