In case you haven’t been living on Jacked Street recently you have been missing out on the awesomeness that is Occlusion Training. At first glance it seems like a gimmicky bro tip to get a better pump. While it’s true that you’ll get one of the best pumps of your life, diving deeper into the subject you realize there is much more going on. Studies are suggesting that Occlusion Training has the ability not only to drive hypertrophy but also muscular strength while working at low intensities.
First, a little history lesson.
This method was created by Dr. Yoshiaki Sato. The idea came to Sato in 1966 when he was attending a Buddhist ceremony. His legs went numb while sitting in the traditional Japanese posture on the floor. He realized that by sitting in this position his blood circulation was blocked in his calves. This “ah-ha” moment is when he conceived the original idea of blood flow moderation training. Over the next 16 years Sato methodically worked on figuring out what was the optimal pressure and ways to restrict venous blood flow. This led him to develop the KAATSU pressure cuff and training system. (1) Unfortunately, the actual KAATSU pressure cuffs system is wildly expensive; we’re talking $1,000-$2,000 per unit. This makes it impractical for anyone outside of the clinical setting. However, there has been a shift in studies to using tools like knee wraps as a practical application.
Occlusion Training, Blood Flow Restriction, or KAATSU training involves wrapping the proximal (closest to the body) end of the muscle that is being worked with something like knee wraps or a pressure cuff to reduce venous blood flow from a muscle. Venous circulation is responsible for carrying blood to the heart, while arterial circulation carries blood away from the heart. Therefore, Occlusion Training allows you to drive more blood to the muscle through the arterial circulation but its exit or venous circulation is blocked. Once occluded, participants in most studies would then perform 3-5 sets of 15-30 repetitions at 20-30% of a 1RM with 30 seconds of rest. (4)
Occlusion “Goldilock Zone”
In a study, researchers divided participants into four groups to identify what the optimal pressure was for Occlusion Training. They tested from 0 mmHg up to 250 mmHg of pressure. The results were 50 mmHg to 15 mmHg produced optimal results. A similar study was done with perceived pressures from 0 to 10 using wraps. They came to a similar conclusion that a moderate pressure of 7 out of 10 produced the greatest stimulus. (4) These studies show, whether you are using pressure cuffs or wraps, that there is a bell curve in respect to the amount of pressure you apply.This means there is a sweet spot; too little or too much pressure and you won’t reap the benefits. What does this mean for all of us don’t have the luxury of having a KAATSU system to precisely dial in the pressure? A good rule of thumb to follow is that the pressure shouldn’t be so great that you have to take the wraps off in between sets. Also Dr. Tom Incledon at the Power Athlete Symposium explained an athlete should maintain capillary refill. If you lose capillary refill then that means you are blocking off arterial circulation as well. Abort!
Proposed mechanisms at work:
Increased fast-twitch fiber recruitment:
- In motor unit recruitment the smaller, slow twitch muscle fibers are recruited first. As intensity increases (i.e weight) the larger fast twitch fibers are recruited as needed. (6) Normally working at an intensity of 20-30% of your 1RM wouldn’t require high motor unit recruitment, thus only slower motor units are recruited. However, when comparing Occlusion Training done at the same intensity it drives a much higher motor unit recruitment similar to that needed at higher intensities. (3)
Elevation of free testosterone:
- In one study saliva samples were taken before and after the first experimental training session each week from two groups. One group did standard resistance training, and the other group did the exact same training but occluded. The test showed a large elevation of free testosterone in the group that used occlusion training. Free testosterone is an important distinction to make because this is what is available for your body to use. (2)
Increased Growth Hormone Secretion:
- Post Occlusion Training there is reported elevated systemic lactate levels. (1) It has been hypothesized that an increase in lactic acid is responsible for an increase in exercise induced growth hormone response. One study tested occluded and non-occluded growth hormone levels pre and 15 minutes post training. The occluded group 15 minutes post exercise showed a concentration of growth hormones 290x higher when compared to the baseline test. While the non-occluded group did not increase much past pre-exercise levels. (4)
- It has been shown that post Occlusion Training there is stimulated anabolic signaling and increased protein synthesis. It appears the cell swelling that takes place is responsible for the anabolic benefits. Post OC training there is a temporary increase in the cross sectional size of the muscle by 10-12%. (5)
Implications on training
**Stay tuned for Part 2 which will dive into all the possible applications for Occlusion Training. It can be a valuable tool used for a multitude of scenarios. Remember determining the proper application of any training “tool” comes down to the answer to our golden question…. What are you training for?
- Abe, T., Kearns, C. F., & Sato, Y. (2006). Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training. Journal of Applied Physiology, 100(5), 1460-1466.
- Cook, C. J., Kilduff, L. P., & Beaven, C. M. Three Weeks of Occlusion Training can Improve Strength and Power in. International Journal.
- 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.
- O’halloran, J. F. (2014). The Hypertrophic Effects of Practical Vascular Blood Flow Restriction Training.
- 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.
- Zatsiorsky, V. M., & Kraemer, W. J. (2006). Science and practice of strength training. Human Kinetics.
Carl Case has been an athlete his whole life, playing both football and rugby in high school. After high school, he directed his focus to rugby where he went on to become a collegiate Midwest All Star. Carl continues to play rugby on a mens team near South Bend, and was part of a National Runner Up team. He found CrossFit and then Power Athlete as a way to fuel his rugby performance. He has been following the Power Athlete methodology since it’s launch in 2009 and attended his first CrossFit Football seminar in August of 2009.
After an introduction to CrossFit in 2007, Carl became a certified coach in 2009 and co-owner of CrossFit South Bend in 2011. In addition to coaching CrossFit and Power Athlete inspired classes at the gym, Carl has been coaching high school rugby since 2009. He uses the CrossFit Football and Power Athlete concepts to help his young athletes identify their goals and provides pointed instruction to help achieve those goals.
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