Blood flow restriction (BFR) training has made its way to the forefront of the latest research regarding training for skeletal muscle hypertrophy cell volumization. While previous interviews have done a fantastic job of describing what BFR is, our goal for the current interview is to provide the reader with a better understanding of how and when to implement it into your current training program. We are very thankful to have Jeremy Loenneke, who has been leading the way in BFR research, take the time to work with us in providing the most up-to-date information regarding BFR. We also wanted to give you a little background on Jeremy and the credentials that he brings into this interview.
Jeremy completed his undergraduate education at Southeast Missouri State University and graduated with a degree in Health Management with an emphasis on Exercise Science in 2008. While he was completing his degree requirements, he completed an internship in Dr. Huey’s Muscle Physiology Lab at the University of Illinois. Following the completion of his internship, he went on to complete his master’s degree at Southeast Missouri State University, earning a degree in Nutrition and Exercise Science. Jeremy is truly a leader in resistance training research, and the quality of his research output clearly displays his commitment and dedication. Jeremy’s continued efforts consistently shed light on some of the latest advancements in Exercise Physiology and skeletal muscle growth. Jeremy is currently working on his PhD in Exercise Physiology under Dr. Mike Bemben in the Neuromuscular Laboratory at the University of Oklahoma. Without further ado, lets get into the interview on the latest advancement in blood flow restriction training.
Q: There’s a ton of evidence supporting BFR’s effectiveness in augmenting skeletal muscle hypertrophy with low load resistance training. Does this augmented stimulus with BFR also apply to resistance training-induced adaptations in tendons and bones?
A: Excellent question, unfortunately there isn’t a ton of evidence available to make a good decision one way or the other. There have been some acute bone marker studies that have suggested it may be beneficial for bone but nothing long enough to see a change in bone. We have published a case study where a bodybuilder successfully rehabbed a fracture with the application of blood flow restriction (BFR), but that should be interpreted cautiously until more data comes along. With respect to studying changes at the tendon, there hasn’t been a lot done on this but the one study available did not find a large change in the tendon with 12 weeks of training. It may be that the load is not high enough to alter tendon properties, but I would be cautious forming too firm of an opinion based on one study.
Q: After an intense mesocycle of training, it’s common to feel pretty “run down” and opt for a week or two of training that is less taxing on the CNS. In such a “deloading” scenario, would BFR be beneficial?
A: I certainly think so and that’s one of the ways I have used it a lot in the past. I think BFR allows a person to take a physical/psychological break from moving heavy weights while still seeing muscular benefits similar to that observed when you lift with heavy weights.
Q: I’ve heard people recommend applying knee wraps at roughly “70% tightness,” where 100% is as tight as possible. For individuals who are new to BFR and unsure if their wraps are too loose or tight, do you have any tips for evaluating if the pressure applied is appropriate?
A: I think that is one way of doing it to ensure that you don’t cut off blood flow completely into the limb. It’s important to remember we want to block venous return not arterial inflow. If you are in pain before you even start exercise, then the wraps are too tight. Any pain/discomfort you have from BFR should be due to the metabolic buildup from exercise. Further, if you are unable to get close to your goal amount of repetitions on the first couple of sets, then the wraps are too tight or the load is too high. If you are sure that the load is around 30% of your maximum and you can’t reach the goal amount of repetitions, then the wraps are too tight.
Q: Where does BFR fit in the training program of the typical strength or physique athlete (i.e. powerlifting, bodybuilding, figure, etc.)? When including BFR work, does the individual need to make any specific changes to volume, intensity, or frequency in other areas of their training program?
A: A typical lifter who is completely healthy can certainly use BFR training but I would never recommend it as their sole form of training. I think BFR can be very helpful for increasing the frequency of training because it doesn’t result in large amounts of damage. There is some evidence that adding BFR with low load exercise at the end of your normal workouts leads to greater gains in strength, likely from an increase in muscle mass. I do think that a person would need to keep this in context with their normal training and realize that if you’ve already maximally stimulated a muscle, adding more and more volume from BFR probably won’t produce anything extra.
Q: In the past, it has often been recommended to perform BFR with 15-30 reps per set, with roughly 30-second rest periods between sets. Would you consider this to be the “ideal” way to approach BFR training?
A: I think the protocol of 30 repetitions followed by 3 sets of 15 is a good protocol to strive for since we know volume is essential to changes in muscle mass. This is not to say that this is necessarily the best but there is a lot of data that shows it is effective. I tend to use that protocol on a lot of the simple lifts like leg extensions/curls/bb curls, etc. and use 3-4 sets of 15 for more complex lifts like the squat.
Q: Unfortunately, knee and lower back pain are obstacles that many lifters face at some point in their career. If you were to design a “BFR-only” leg day, what would it look like? (For this question, assume the lifter is healthy enough to complete all lower body exercises, but wants to use light weight to avoid heavy loads on their knee/low back)
A: Leg Press + BFR (3-4 sets of 12-15 reps, 30s rest, 30% 1RM)
Leg Extension + BFR (30 reps, 3 sets of 15 reps, 30s rest, 30% 1RM)
Leg Curls + BFR (30 reps, 2-3 sets of 15 reps, 30s rest, 30% 1RM)
Calves + BFR (30 reps, 3 sets of 15 reps, 30 s rest, 30% 1RM)
I would have them do this 2-3x week until they could start transitioning back into higher load training. If a person is new to BFR I would have them leave the wraps on for the first 2 exercises and then take them off for around 5 minutes to restore normal blood flow before wrapping them again for the final 2 exercises. As a person becomes more experienced I would work on them completing the whole exercise session without taking the wraps off.
Q: Would you speculate that BFR training offers any advantages specific to the athlete deep into contest prep (for example, by affecting vascularity, fullness, or recovery time between sessions)?
A: I think recovery would certainly be one of the biggest benefits of using BFR during contest prep. As I said before, some days having a physical/psychological break from having to move heavy weights is just what a person needs in the middle of a caloric deficit. I’ve heard conjecture that people feel more vascular after adding BFR into their contest prep but I remain cautious of putting too much stock behind claims that are hard to objectively study.
Q: What are your favorite and least favorite muscle groups to train with BFR?
A: My thoughts on this are more dependent upon the movement and it seems to change for me depending on the day. There are days I love training the squat with BFR and others where that’s the last thing I want to do. My all-time favorites would probably be knee extensions and bicep curls based solely on the “pump” you get from those movements.
Q: You’ve played a prominent role in laying a large foundation of BFR research. In what direction do you see future BFR research going?
A: As you stated before, we know BFR combined with resistance exercise works. The big questions remaining are 1) how does it work? and 2) how can we make the stimulus even more effective? My big interest is studying the methodology of applying the stimulus and I have been and will continue to focus on that in the near future.
Q: Are there any specific populations that should abstain from BFR?
A: I’m always cautious of having anyone with any kind of pre-existing damage to the vascular system exercise with BFR. In addition, if you are at a high risk of thromboembolism I would be extremely cautious of adding this to your training program.
Some risk factors for thromboembolism include having more than one of the following:
- Classified as Obese based on a Body Mass Index of > 30
- Diagnosed Crohns or Inflammatory Bowel Disease
- Past fracture of a hip, pelvis, or femur
- Major Surgery within the last 6 months
- Varicose veins
- Family history of Deep Vein Thrombosis or Pulmonary Embolism
Q: As many are aware, you’re approaching the end of your doctoral studies. What does the future hold for Jeremy Loenneke?
A: My data collection and writing for my dissertation is largely finished and I will be defending it early next year. Right now I’m trying to find a job or post-doc where I can continue my research in the area of BFR and muscle hypertrophy.
Matt Jansen and Eric Trexler – Strength and Contest Prep Coaches. CSCS
