Q- For people who may not know the name Jeremy Loenneke can you tell the readers a little about your personal and professional background?
I’m from Redhawk Nation, otherwise known as Southeast Missouri. I grew up there and came across natural bodybuilding in about 2003-2004. I saw a video of this crazy man Layne Norton moving a ridiculous amount of weight. I did my undergraduate at Southeast Missouri State University and graduated with a degree in Health Management with an emphasis in Exercise Science. Prior to finishing my undergraduate degree I completed an internship in Dr. Huey’s muscle physiology laboratory at the University of Illinois. It was during my time there that I met Layne Norton and the rest of the crew who are still some of my best friends to this day. Following my internship, I completed my masters back at Southeast Missouri State University in Nutrition and Exercise Science under my mentor Dr. Joe Pujol. My focus was on blood flow restriction training using a practical mode (i.e. knee wraps) of application. Following my masters I started working on my PhD in Exercise Physiology at the University of Oklahoma in the Neuromuscular Laboratory under Dr. Mike Bemben. I am fortunate in that I work with outstanding individuals not only in the lab at OU, but from other laboratories across the nation. Just to acknowledge a few people in no particular order who have helped me generously through my life: Takashi Abe, Mike Bemben, Joe Pujol, Jake and Gabe Wilson, Chris Fahs, Lindy Rossow, Layne and Isabel Norton, Robert Thiebaud, Jeremy Barnes, Austin ‘Stone Cold’ Thrower and Ryan Kloeppel. There are many more than that, but we would be here all day if I listed them all. I feel it is important to acknowledge these people, because without them, we wouldn’t be having this interview.
Q- What is Occlusion Training and how did it get on your radar and become something you wanted to research?
I came across occlusion training or blood flow restriction (BFR) training as I prefer to call it while I was interning at a laboratory up at the University of Illinois. I was working out at Gold’s Gym in Champaign when Layne Norton, Gabriel Wilson, and Chris Fahs introduced it to me. I was skeptical at first, but the more I read about it the more interested I became. It was literally one of the first things in my life that I became absolutely 100% passionate about. It was something that I needed to try and learn everything about and it has literally been on my mind every single day for about 4 ½ straight years. When I left the University of Illinois to go and complete my masters at Southeast Missouri State University, my mentor suggested that I start actually collecting some data on it. The rest is pretty much history.
Q- What is the main purpose of Occlusion training or Blood Flow Restriction (BFR)?
We tend to lean towards the term of Blood Flow Restriction (BFR) rather than occlusion because the word “occlusion” gives people the idea that we are completely cutting off blood flow to the limb, which is not the goal of BFR at all. The purpose of BFR is to allow blood into the muscle, but to largely reduce the amount that leaves the muscle (i.e. venous pooling). If you have cut off arterial inflow, then you are doing it wrong. BFR allows beneficial adaptations to occur at very low exercise loads/intensities. This is important for those who might be injured, during a period of deloading, or when you just don’t have the mental focus to train heavy that day. For the healthy gym goer they can supplement their training with BFR and see benefits, but it wouldn’t make a lot of sense to make it your primary or sole mode of exercise. However, there are different levels of effectiveness for BFR and I usually separate them into 3 different categories.
- The first is the application of BFR, in the absence of exercise. This stimulus does not appear adequate to produce muscle hypertrophy, however it seems like it can maintain or slow down losses in muscle mass and strength during times of unloading (e.g. recovering from surgery).
- The second is the application of BFR with slow walking or cycling exercise. This stimulus is capable of producing muscle hypertrophy; however the increases observed are substantially less than what is observed with BFR in combination with resistance training. It is important to remember that this type of exercise needs to be completed with SLOW to moderate walking/cycling. DO NOT sprint under BFR. The point is to work at low intensities, don’t lose sight of that.
- The third and most effective mode is applying BFR in combination with low load resistance training. The increase in muscle mass and strength from this will be much greater than what is observed with BFR in combination with slow walking/cycling. It is very important to make sure that this type of exercise is completed with a LOW load. If you do BFR in combination with a high load it defeats the purpose of the stimulus and appears to be largely ineffective. This type of exercise should be completed with a LOW load and HIGH volume.
Q- What is the mechanism of how BFR causes hypertrophy?
That is the million dollar question. It is often erroneously said that the mechanisms behind BFR are an increase in metabolic buildup (e.g. lactate) which cause fatigue and the recruitment of fast twitch fibers. While this is very much true with BFR in combination with resistance training it provides little explanation for what is occurring with BFR in the absence of exercise or when combined with slow walking/cycling. To illustrate, there is no muscle contraction in the absence of exercise therefore fatigue and recruitment can’t be occurring. There is also not a significant increase in lactate with BFR in the absence of exercise or when combined with slow walking. We have hypothesized and have data that suggests that the foundational mechanism that is likely present with all forms of BFR is an acute fluid shift induced increase in muscle size (i.e. muscle cell swelling). Said another way, the fluid shift that occurs from applying BFR is able to cause the muscle cell to swell which may be important for muscle anabolic signaling. As you can tell, the mechanisms behind BFR are complex and likely build upon each other for great adaptation. That is likely the reason why BFR in combination with low load resistance training is the most effective because you get 1) cell swelling, 2) metabolic buildup, 3) fatigue, and 4) increased fiber type recruitment whereas with BFR in the absence of exercise you are only getting cell swelling.
Q- What is the most practical instrument to use as cuffs in the gym? Do you recommend knee wraps?
For practical application, I think knee wraps are excellent. There is also some acute and chronic research to support their use. It is true that you cannot set the pressure like you can on the devices that we use in a research laboratory, but for the general person that is not really important. For example, in a research setting it is very important to understand and control for absolutely everything you can. The gym goer shouldn’t concern themselves with that and should focus on causing a fluid shift by applying the knee wraps and completing an adequate volume of work.
Q- Are there specific muscle groups which have been shown to respond best to BFR? Are there any muscle groups it would not be possible to use BFR with?
For a long time it was thought that BFR was only working for the muscle groups that were below the restriction. For example, if you restrict blood flow to the upper arm, it was thought that only the biceps/triceps would see positive adaptation since they were the only muscles under BFR. However, recently it has been observed that the chest can also increase size and strength even though it is technically not under BFR. It is unknown exactly how that is occurring, but there is data to suggest that acute muscle cell swelling might be playing a role, as there are greater acute increases in chest muscle size following bench press exercise with BFR applied to the arms.
Q- How tight should the cuffs be to induce the most optimal results?
This is a great question. First it is important to understand that the wraps should be placed at the top of the arms or at the very top of the legs (not around the knee). Wrap the wraps right on top of each other to make the final application not much wider than the normal wrap width. The wraps should be applied “snug” but NOT excessively tight. For example, if you apply them and you are in pain before you have completed a repetition, then the wraps are too tight and you should remove and loosen them. Any discomfort/pain you have from BFR should for the most part be coming from the buildup of metabolites. With resistance training, it is important to make sure that the load you are lifting is LOW…for example, 20-30% of your maximal weight (be honest with yourself as to how strong you actually are). I typically recommend that you shoot for 30 repetitions in the first set followed by 3 sets of 15, with 30 seconds rest between each set. If you are not even getting close to those repetitions, either the load is too heavy or the wraps are too tight. Remember, the wraps need to be ‘snug’ enough to cause a fluid shift, not to completely cut off blood flow to the limb.
Q- Is BFR training something you would recommend to bodybuilders to help bring up lagging body parts?
Absolutely, I would definitely recommend it for a lagging body part. Perhaps after the completion of some high load training you could finish with some low load training under BFR. I have had several bodybuilders (Pro and Amateur) tell me that this has worked for them in the past. More importantly than that, there are over 40 published chronic training studies on the topic, which suggest that it is beneficial.
Q- How often should one use BFR?
Being that when done correctly you get minimal muscle damage, it is very common in the literature to train with very high frequencies (up to twice a day). However, since most people are also training with heavy loads, it might make sense to just use it in conjunction with your normal training split. For example, if you do Legs on Mon/Friday then use BFR with legs on Mon/Friday, not every other day of the week.
Q- Is there a special set/rep/load protocol which has been shown to produce the best results?
With walking/cycling I would recommend working your way up to about 20 minutes of LOW INTENSITY exercise. I would probably start with 10 minutes your first couple of times to get used to it.
With resistance training I would recommend working your way up to 4-5 sets (I’d probably start with 2 sets your first few times). I think it is important to make sure you are getting adequate volume so I would advocate shooting for 30 reps in the first set followed by 3 sets of 15 (30 seconds rest). You might not be able to get all of them, but you should be getting close. As I said earlier, if you are not, then the load is too heavy or the wraps are too tight. I would also mix in some failure training every once in a while, meaning you apply BFR then complete 3-4 sets to fatigue.
Some take home points on BFR from Jeremy Loenneke
- Remember the wraps should NOT cut off blood flow completely.
- Remember that BFR should be performed in conjunction with low intensity walking/cycling or LOW LOAD resistance training (20-30% max).
- It is important to understand that your heart rate will be elevated with this type of exercise because you are reducing venous return, so basing your exercise on %HR with BFR exercise is not valid.
- If you have a condition that may compromise your vascular system, I would not recommend performing BFR exercise.
- Do the work…science explains how things happen, but it all comes down to doing the work. To become who no one else is, you must work like no one else does #outwork.