What is Blood Flow Restriction Training?

Modern day BFR training

The concept of blood flow restriction is 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-level athletes to intensive-care patients. This technology has been applied in a vast number of different environments including musculoskeletal 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 it?

Blood flow restriction training is typically used in combination with low-intensity resistance exercise or cardiovascular training. It involves the application of a pneumatic cuff device to limit arterial blood flow to a limb, while fully restricting venous outflow in working muscles. By modifying blood flow in this way, users can train at remarkably low intensities, and achieve comparable training results as more traditional resistance training methods.

The Suji Device: AI-Powered, BFR Training Equipment

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 of as little as 20% 1RM (Takarada et al. 2002). Early research achieved 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, however, these pathways will be explored in future blogs.

Why is it important?

Using a low-intensity training stimulus such as walking and light resistance exercise exposes users to a low mechanical load. This means less force going through bones, tendons, muscles, and joints. This means that people who are typically considered contraindicated to high-intensity exercise, such as those who are injured, the elderly, or those in poor health, may still be able to benefit from rigorous physical activity. Within the current literature, blood-flow restriction training is currently being explored in over 25 conditions of clinical disease and musculoskeletal rehabilitation. A recent survey of practitioners currently using BFR revealed that the most common objectives of BFR exercise were to induce muscle hypertrophy, followed by use during injury rehabilitation. Universities and elite or professional sporting teams are the most frequented users of BFR, with the age bracket of 21-30 years being the most common age bracket (Patterson et al. 2017).

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 diseases worldwide.

References:

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
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
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/
Patterson, S., et al., The role of blood flow restriction training for applied practitioners: A questionnaire based survey. Journal of Sport Sciences, 2017, 36 (2): 123-130. https://pubmed.ncbi.nlm.nih.gov/28143359/.
Patterson, S. et al., Editorial: Blood Flow Restriction: Rehabilitation to Performance. Frontiers in Physiology, 2021. 12: p. 1-4.