Blood Flow Restriction Training (BFR)

Also known as Occlusion Training or Kaatsu Training was originally conceived and developed in Japan in the late 1960’s by Yoshiaki Sato and termed KAATSU training. It most commonly involves resistance training with low loads of around 20 – 30% of 1 Rep max (1RM), using wraps, cuffs or bandages applied around the top part of trained limb (usually with a perceived tightness of 7 out of 10).

Research has demonstrated that using low-load resistance training with BFR can produce significant strength and hypertrophy gains. BFR training has been found to yield hypertrophy responses comparable to that observed with heavy-load resistance training. Studies have also shown using walk-training along with BFR to the legs can increase muscle strength and size.

BFR training can be beneficial in producing muscular adaptions and anabolic responses with lower loads and lower volumes than comparable resistance training while giving joints, ligaments, and tendons a break from heavy lifting. The practical application is it can then be used when moderate to high loads are often not feasible in clinical populations or people with injuries and can be used as a rehabilitation tool.

It can also be used as a de-load strategy after a few weeks of heavy lifting or even at times when there just isn’t the mental focus to train heavy on a certain day.  It is also good for anyone who wants to mix up their training or something different as a tool to supplement their training.

​The muscle growth mechanisms are not entirely clear but metabolic stress plays a role in hypertrophy-

​With BFR training you restrict the venous return of blood flow from the muscle (not restricting blood flow to the muscle). By restricting only, the venous return from the muscle, this then causes the blood to pool in the muscle.  As the sets of the exercise progress there will be a greater total volume of blood & metabolites accumulated within the muscle tissue. The idea is now as blood accumulates, the muscle tissue is forced to expand, and type II muscle fibres are left to perform a greater portion of the work as the aerobic, type I fibres are quickly fatigued due to reduced levels of oxygen within the tissue. These effects lead to muscular hypertrophy through much lower training loads as would otherwise be necessary during exercises not using BFR. 

Some Research on Blood Flow Restriction Training (BFR)

A systematic review and meta-analysis of peer-reviewed literature examining BFR training in clinical MSK rehabilitation (Hughes et al)

• The clinical relevance of this review is the demonstration that low load- BFR training can provide a more effective approach to low- load  and more tolerable approach to heavy- load rehabilitation.
•  Individualised low- load BFR training prescription may provide a comparable surrogate foe heavy-load training while minimising pain during training.

• BFR may facilitate early engagement in low-load strength training with limited joint stress in a broad range of clinical populations.​

Resistance Training on Muscle Adaptations Using a Systemic Review and Meta-analysis Procedure (Lixandrao et al)

High Load Resistance Training versus Low Load Blood Flow Restriction Training-

• High- Load Resistance Training was > 65% 1 rep max (HL- RT)
• Low-Load Resistance Training was < 50% 1 rep max associated with blood flow restriction (BFR-RT)

Based on the present data-

• Maximum muscle strength maybe optimised by specific training methods (i.e. HL-RT) while both HL and BFR-RT seem equally effective in increasing muscle mass.
• Importantly, BFR-RT is a valid and effective approach for increasing muscle strength in a wide spectrum of ages and physical capacity, although it may seem particularly of interest for those individuals with physical limitations to engage in HL-RT

The studies have shown that low-intensity resistance training with vascular muscular venous blood flow causes muscle hypertrophy and strength gain.

​Muscle Size & Strength are Increased Following Walk Training With Restricted Venous  Blood Flow From The Leg Muscle- Kaatsu Walk Training (Abe et al).

This study investigated the effects of daily physical activity combined with Kaatsu (BFR)

• The study examined the acute and chronic effects of walk training with and without Kaatsu on MRI-measured muscle size and maximum dynamic and isometric strength along with blood hormonal parameters.
• ​Nine men performed Kaatsu-walk training, and nine men performed walk training alone (control group).​
• Serum growth hormone was elevated after acute Kaatsu-walk exercise but not in control-walk exercise.
• MRI-measured thigh muscle-cross sectional area and muscle volume increased by 4-7% and 1 RM and maximum isometric strength increased by 8-10% in Kaatsu-walk group.
• There was no change in muscle size and dynamic isometric strength in control-walk group.

The results suggest that the combination of leg muscle blood flow restriction with slow walking training induces muscle hypertrophy and strength gain, despite the minimal level of exercise intensity.

Kaatsu-walk training may be a potentially useful method for promoting muscle hypertrophy, covering a wide range of the population including the frail and the elderly

The Effects of Elastic Band Train​ing BFR on Muscle Size and Vascular Function in Older Women

This study by Yasuda et at concluded-

• Low intensity squatting and knee extension training with BFR using elastic bands for resistance elicited marked gains in quadriceps muscle cross sectional area and strength and did not decrease vascular function in older women
• The results demonstrated that low intensity elastic band BFR training would be beneficial in the development of safe and effective methods of sarcopenia care and prevention in older adults.
  

Guide on How To Use BFR

• Placement of wraps or cuffs- Position them as high as possible on limbs being trained. If wraps are positioned too low there will  it will not yield desired effect.​,
• For example- if training legs, wrap around just below the glutes or for arms as high up the biceps as you can.
• Tightness of the cuffs or wraps should on a scale of between 1 to 10- feel around a 7, it should feel snug but not excessively tight.
• There are various ways that BFR can be incorporated into training
• Single joint exercises are best choices- Good exercises include- biceps curls, triceps push downs, leg extensions, leg curls, calf raises etc.​
• Lighter weights and higher reps are suggested (around 20-30% 1 rep max). 20-25 reps on the first set seem to be a good range.
• Using shorter rest periods between sets help heighten metabolic stress.
• For example on 1st set of exercise you might manage 20-25 reps  take a short rest then next set if you maintain the same load you will find you can do less reps. Each set you will find you will do less reps.This will happen due to metabolic stress being placed on muscle worked. 
  
• Even though light weights are being used this is tough! As the reps go on limbs will feel heavier and heavier and fatigue will kick in- Push through the reps, try and squeeze those muscles and feel the pump!
  
• Keep wraps on throughout the sets of muscles used  as taking them off between sets will reduce metabolic stress, remove them after final set for that exercise has been performed.
• Enjoy the pump!
  

Below is a video of myself training biceps using BFR. Even using light weights this felt tough!

References

• Abe et al (2005). Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training· 
•  Lixandrão et al (2008). Magnitude of Muscle Strength and Mass Adaptations Between High-Load Resistance Training Versus Low-Load Resistance Training Associated with Blood-Flow Restriction: A Systematic Review and Meta-Analysis. Sports Med. 2018 Feb;48(2):361-378. doi: 10.1007/s40279-017-0795-y
• Hughes et al. Blood flow restriction training in clinical musculoskeletal rehabilitation: a systematic review and meta-analysis. BJSM. Vol 53. Issue 13 ·  
• Vanwye et al. (2017). Blood Flow Restriction Training: Implementation into Clinical Practice. Int J Exerc Sci. 2017 Sep 1;10(5):649-654. eCollection 
• Yasuda et al (2016) Thigh muscle size and vascular function after blood flow-restricted elastic band training in older women. Oncotarget. 2016 Jun 7;7(23):33595-607. doi: 10.18632/oncotarget.9564.
• Brad Schoenfeld. Blood Flow Restriction Training. T Nation. www.t-nation,com/training/blood-flow-restriction/training
• Layne Norton. Blood Flow Restriction Training: The Next Generation of Anabolic Exercise.https://www.biolayne.com/articles/training/blood-flow-restriction-training-the-next-generation-of-anabolic-exercise/

Jamie Miller- Personal Trainer
UK Fitness Personal Training
​Aberdeen

FITNESS, NUTRITION & PERSONAL TRAINING​