Blood Flow Restriction

Wait a minute…. you’re telling me to restrict blood flow while resistance training?  Doesn’t that lead to blood clots, embolus, etc.?  You’re out of your mind man.”  We hear this conversation far too often when discussing a novel technique used to induce muscle growth.  When considering resistance-training variables, everyone traditionally mentions drop sets, super sets, different periodization models, etc.   Now that you’ve incorporated and tried those techniques, it is time to add a new tool to your repertoire.  Let’s examine what BFR is and how you can incorporate it into your training program.

WHAT IS BLOOD FLOW RESTRICTION TRAINING?

Blood flow restriction (BFR) {sometimes called occlusion training}, as the name implies, involves decreasing blood flow to a working muscle, by application of a wrapping device, such as a Kaatsu device, blood pressure cuff, or knee wraps.  This technique is typically used in conjunction with lighter weight (30-50% 1RM) and performed on the legs and arms, although some research suggests that there may be benefits for other body parts as well (Yasuda et al).  Interestingly enough, some research shows that even walking while BFR can increase muscle size!! (Abe et al)  Thus, the real question becomes:  How in the world is this happening?!?

WHAT ARE THE METHODS THROUGH WHICH BFR WORKS?

There are several mechanisms through which BFR may work but we will touch on the 3 primary mechanisms:

1)     Increased Muscle Activation/Motor Unit Recruitment

Typically lifting 30-50% of your 1RM trained to non-failure would only target the Type I (slow twitch fibers).  However, with BFR + exercise we see that even 30% of your 1RM can target the larger, Type II fibers that are important for muscle growth and size.  Interestingly enough, Yasuda et al (2010) found greater muscle activation in the chest muscles when wrapping the cuffs at the top of the arm and performing a bench press movement.  This indicates a possible benefit for muscles other than the ones that are purely “restricted.”

2)     Increased Metabolic Stress

Don’t fear.  Acute metabolic stress, such as that seen when training can actually be a good thing.  One of our colleagues Dr. David Gundermann found that the plasma lactate response seen during BFR at 30% 1RM was significantly higher than high volume workouts using 70% 1RM!  Why does this matter?  In fact, research indicates that increased metabolic stress was linearly associated with changes in muscle cross-sectional area.  As if that wasn’t enough, Dr. Gundermann did an experiment where he took muscle cells and exposed them to lactate.  Just exposing them to lactate alone drastically increased downstream targets of mTOR which we all know is the master regulator of protein synthesis.

3)     Increased Cell Swelling

Arnold used to say he “trained for the PUMP!”  Maybe he was on to something because there appears to be evidence that intracellular metabolites cause cell swelling which may activate anabolic pathways.

HOW CAN YOU INCORPORATE BFR INTO YOUR PROGRAM?

Stop lifting heavy weights.  Everything you have been doing has been a lie.  Just kidding again.  It’s important to remember that this is a TOOL to use in addition to your regular resistance-training regime.  You can use it as a finisher, but you can also use it if you’re flat out tired, injured, or just want to train on Saturday yet you still feel like you got hit by a truck from a Friday night out.  Some important considerations to consider:

1)     Scheme Typically Used Is: 30-15-15-15 reps with 30 seconds rest:

Keep rest periods short.  It’s all about pumping them out and keeping that metabolic stress and cell swelling up.

2)     It’s Not about Damage:

One of the kings of BFR, Dr. Jeremy Loenneke, did an interesting study that showed that the concentric portion of the contraction seemed to be more important than the eccentric.  The goal with BFR isn’t to create muscle damage.  Pump out the reps with proper form…proper form aka don’t be the guy at the gym doing the hip thrust – bicep curl combo workout.

3)     Wrap at a moderate, snug pressure:

If you can imagine 10/10 being as tight as humanly possible, a 6-7 out of 10 is ideal.

4)     Device:

You can use knee wraps or even plastic tourniquets:

5)     Keep your Wraps On:

It will be painful and it will hurt but keep your wraps on the entire time (30-15-15-15).  Now if you start turning blue/purple, that might be a time to release them and rewrap.

Research (Leubbers et al) has found that doing your supplemental work with BFR can result in significant gains in muscle size.  So as a takeaway, you can use BFR when you are injured, as a finisher for your workout or as an entire workout itself on a day when you feel pretty crappy, yet still want to get some work in.

References:

1. Abe, T., Sakamaki, M., Fujita, S., Ozaki, H., Sugaya, M., Sato, Y., & Nakajima, T. (2010). Effects of Low‐Intensity Walk Training With Restricted Leg Blood Flow on Muscle Strength and Aerobic Capacity in Older Adults. Journal of Geriatric Physical Therapy, 33(1), 34-40.
2. Fujita, S., Abe, T., Drummond, M. J., Cadenas, J. G., Dreyer, H. C., Sato, Y., &  Rasmussen, B. B. (2007). Blood flow restriction during low-intensity resistance  exercise increases S6K1 phosphorylation and muscle protein synthesis. Journal of  Applied Physiology, 103(3), 903-910.
3. Loenneke, J. P., Wilson, J. M., Marín, P. J., Zourdos, M. C., & Bemben, M. G. (2012). Low intensity blood flow restriction training: a meta-analysis. European journal  of applied physiology, 112(5), 1849-1859.
4. Lowery, R. P., Joy, J. M., Loenneke, J. P., Souza, E. O., Machado, M., Dudeck, J. E., &   Wilson, J. M. (2014). Practical blood flow restriction training increases muscle hypertrophy during a periodized resistance training programme. Clinical   physiology and functional imaging, 34(4), 317-321.
5. Luebbers, P. E., Fry, A. C., Kriley, L. M., & Butler, M. S. (2014). The effects of a 7-week practical blood flow restriction program on well-trained collegiate athletes. The Journal of Strength & Conditioning Research, 28(8), 2270-2280.
6. Wilson, J. M., Lowery, R. P., Joy, J. M., Loenneke, J. P., & Naimo, M. A. (2013). Practical blood flow restriction training increases acute determinants of    hypertrophy without increasing indices of muscle damage. The Journal of Strength & Conditioning Research, 27(11), 3068-3075.
7. Yasuda, T., Fujita, S., Ogasawara, R., Sato, Y., & Abe, T. (2010). Effects of low‐ intensity bench press training with restricted arm muscle blood flow on chest muscle hypertrophy: a pilot study. Clinical physiology and functional imaging, 30(5), 338-343.
8. Yasuda, T., Loenneke, J. P., Thiebaud, R. S., & Abe, T. (2012). Effects of blood flow restricted low-intensity concentric or eccentric training on muscle size and strength. Plos one, 7(12), e52843.
9. Yasuda, T., Ogasawara, R., Sakamaki, M., Ozaki, H., Sato, Y., & Abe, T. (2011). Combined effects of low-intensity blood flow restriction training and high-intensity resistance training on muscle strength and size. European journal of applied physiology, 111(10), 2525-2533.