blood flow restriction training

Blood Flow Restriction Training: An Interview with Jeremy Loenneke

Like injecting heroin, Blood Flow Restriction training involves wrapping your limbs so that the blood can’t exit your muscles; all while lifting weights.
Jason Maxwell sat down to chat with the “Blood Flow Restriction Expert”, Jeremy Loenneke.  Here’s what happened.

Jason Maxwell: So, Jeremy, I just want to start off and tell me 3 important things about yourself: who you are, what you do, and how the JMax Fitness Community can benefit from knowing who you are.

Jeremy Loenneke: I’m an Assistant Professor of Exercise Science at The University of Mississippi.

I teach and do research in the areas of skeletal muscle physiology. My main research interest is blood flow restriction (BFR) and how it may be used to attenuate atrophy and/or stimulate muscle growth when it is combined with low load resistance training.

I suppose your followers could benefit by “knowing me” as I can sometimes help bridge the gap between what the research says and what it means for the everyday person. I say sometimes, because there is a lot of research that I don’t have the proper training to understand much less pretend to understand.

blood flow restriction training

Jeremy Loenneke practices what he preaches.

 Jason Maxwell: I’ve always thought of you as “the man” when it comes to BFR training. Many authority figures praise you like myself, Dr. Layne Norton, and Pro Bodybuilder John Meadows.  In a nutshell, what is BFR training?

 Jeremy Loenneke: I always appreciate those kind words but I’ll also mention that there are other people doing great work in this area and I feel lucky to have worked with several of them.

BFR is a technique where we apply a cuff/wrap and restrict blood flow into a muscle, causing blood to pool in the limb. It’s important to keep in mind that this is a short term thing and we aren’t restricting blood flow for hours at a time (big difference between acute and chronic).

It’s also important that we remember we are not trying to occlude blood flow into the muscle completely, we only want to partially restrict it. When BFR is combined with low intensity aerobic exercise there appears to be a small increase in muscle size and strength. However, when it is combined with low load resistance training (30% max) it produces increases in muscle size and strength similar to that observed with high load resistance training.

Jason Maxwell: So we’re cutting off the blood from exiting the muscle, but at the same time allowing the blood to pool into the muscle; and if we do this properly we can increase the size and strength of a muscle while using light weights? Why do you think that this works for strength and hypertrophy?

 Jeremy Loenneke: Correct, it is going in but not a lot is coming out.

How does low load resistance training in combination with BFR work? There appears to be a lot going on and probably a lot more going on than we currently know.

Some of the potential reasons include a short term increase in muscle size (cell swelling), an accumulation of metabolites into the muscle due to the restriction of blood flow (metabolic accumulation), a proliferation of satellite cells potentially from contraction in combination with a hypoxic like stimulus, and a decrease in myostatin which may be related to the metabolic accumulation. These may be playing some role in increasing the size of muscle which ultimately leads to a stronger muscle. I will say, I don’t think cell swelling by itself is enough. I think cell swelling might be important but it doesn’t necessarily mean that the more it swells acutely during exercise (the pump) will translate into greater muscle mass.

blood flow restriction training

BFR Training on legs. Notice the wraps at the top of the thighs. Photo courtesy of All Natural Muscle.

 Jason Maxwell: Awesome stuff. How would you program it into your workout? I’m talking sets, reps, rest periods, muscle groups, and when to put it into your training phase.

 Jeremy Loenneke: Programming is a pretty hard question to answer so all of these points are just general recommendations.

Also, if you are using this in combination with your regular training, make sure you keep this additional training in context with your overall exercise volume. If you have already hit a muscle group with 3-4 different exercises and then hit the same muscle group with BFR, you will likely see minimal benefit…the law of diminishing returns is a real concept.

But, in general here are a few points:

  1. You can use it on days when you just “don’t have it” in the gym
  2. You can use it one day and train normal a different day
  3. You can use it at the end of your normal workout

Exercise Selection (among others)

  1. Squats
  2. Leg press
  3. Leg Extension
  4. Leg curl
  5. Bench Press*
  6. Shoulder Press*
  7. Tricep Extension
  8. Bicep Curl
  9. Lat Pull-down*

 *There is some data to suggest that the chest can grow even though it isn’t under direct blood flow restriction. This might be working by “fatiguing” the triceps making the chest pick up the load. This hypothetically would also hold true for the shoulder press and lat pulldown. For those who are decently advanced, I’d probably super set the bench press and shoulder press with an exercise that hits a muscle that is directly under blood flow restriction (i.e. tricep pressdown)…same goes for lat pulldown (i.e. bicep curl).

blood flow restriction

BFR Training on the bicep curl. Note wraps at the top of the arms. Image courtesy of Youtube.

Repetition Protocols

  1. One set of 30, 3 sets of 15: This protocol is commonly done throughout the literature
  2. 3-4 sets of 12-20: I use lower reps on squat just because it’s a difficult skill
  3. 3-4 sets to failure (I wouldn’t make this the primary protocol)

Loading and Rest Periods:

The load should be around 20-30% of your max. There does not appear to be any benefit to training at a higher percentage of your max in combination with BFR. I recommend rest periods of 30-60s between sets.

Jason Maxwell: This is great, but I have two questions. For the exercises above, where would you wrap your limbs?  How tight?

Jeremy Loenneke:

  1. For all lower body exercises, the wraps go at the top of each leg. The top of the legs is the only place I recommend putting them, even if you are doing calves. I do not recommend using them around your knees for BFR exercise.
  2. For the upper body, I recommend wrapping them at the top of the arm.

This is a link to an illustration of where the wraps should go. As you can see, I recommend using a narrow wrap for the upper body. Essentially I cut off the end of one of my knee wraps, cut it up the middle, and then burn the sides so they don’t fray.

As for how tight…it’s obviously previously difficult to determine pressure using this practical stimulus. However, the following guidelines may be useful to determine if the wraps are applied too tightly. Some newer acute data from our group suggests that tighter may not be better (this needs to be confirmed through training studies).

  1. If you are in pain before you start, the wraps are too tight. The discomfort you feel should largely be due to the buildup of metabolites with exercise
  2. If you are unable to get close to the 30-15-15-15 repetitions, then the load is too high or the wraps are too tight. If you are sure that the load is low (20-30% max) then your wraps need to be loosened.
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Jason Maxwell: I've noticed two things with BFR. First, the pump is crazy. Sometimes my arms feel like they're pumped for as long as 24 hours. Second, sometimes all the capillaries in my arms will rise to the surface and my arms will be red for days (this generally happens if I haven't used BFR for a few months). Have you ever heard of this happening before?

Jeremy Loenneke: The acute increase in muscle size (AKA “the pump”) is commonly observed following BFR; however, we’ve never observed it to be elevated for 24 hours.

At one time we thought this was an important mechanism but now we’re not as confident. I think the acute swelling response may be important for muscle growth but not in itself sufficient. With respect to your second question, I’ve seen something similar while BFR is applied but I’ve never seen it last for days. I’d speculate that the pressure may have been too high, but I’m not certain.

Jason Maxwell: Ya, that was my hypothesis also. So what's in store for you in the future?

Jeremy Loenneke: I’m currently working really hard to establish my research here at The University of Mississippi.

The faculty here are great and the support has been tremendous, so I have no excuses not to be successful. With our research here, we really want to start testing some of our thoughts through well controlled training studies.

We have compiled a lot of acute data and have a pretty good idea of what’s going on, at least in the short term…but it’ll be interesting to see if these short term changes actually translate to differences in muscle adaptation. In addition, we have some studies lined up to investigate the site specific loss of muscle mass with age. I’m really excited to see if we can tease out some possible explanations for why muscle mass appears to decrease much more in the front of the thigh (i.e. quadriceps) as compared to the back of the thigh (i.e. hamstrings).

blood flow restriction training

"I’m really excited to see if we can tease out some possible explanations for why muscle mass appears to decrease much more in the front of the thigh (i.e. quadriceps) as compared to the back of the thigh (i.e. hamstrings)." Photo courtesy of Muscle & Fitness.

Outside of that, I will seek to try and do my best to keep educating the world (mostly through social media) on what the science is actually saying. It’s tough out there for people, because many in the industry appear more interested in making money and scaring people than educating them on what the available evidence actually says. That’s why we have to listen to ridiculous discussions on “what to never do” or “what to always do or else” or whatever. Quite often these posts are written by people who have absolutely no idea what they are talking about and of course, it’s their message that gets spread like wildfire.

Jason Maxwell: Awesome stuff Jeremy. Where can people find you online, and do you have any final words for JMax Fitness?

Jeremy Loenneke: People can follow me on twitter @jploenneke. I’ll leave your audience with the following points:

  1. Blood flow restriction may be a useful tool, but you certainly don’t have to use it for “optimal” muscle growth/strength.
  2. Supplements are for the most part a drain on your bank account with very little return.  Eat food.
  3. Personal trainer’s do personal training, not personal dietary advice.
  4. Genetics matter, it isn’t only about “how bad you want it”
  5. Exercise is Medicine
  6. You cannot out diet a bad training program

Jason Maxwell: Those are all fantastic points. Thanks for taking the time to do this interview, and I'm glad that we had the chance to introduce a lot of people to one of the leading researchers on blood flow restriction and hypertrophy training.

Jeremy Loenneke: Thanks for having me Jason

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