Enhance your current exercise regime with our patented B Strong BFR Training System

B Strong’s patented blood flow restriction training system was developed by James Stray-Gundersen, MD Sports Medicine & Science, who worked with elite-level athletes, and Sean Whalen, MS Engineering, a successful entrepreneur in the rehabilitation and sports performance industry.

With Sean’s 15+ years of tech experience in physical rehabilitation and entrepreneurship, and Jim’s 30+ years at the top level of elite sports and the sports performance field, they set out with the goal of making a BFR system for everyone, designed with hardware and software ingenuity, scientific acumen, and vigorous yet simple education.

This evolved into B Strong, a safe, effective, affordable and easy-to-use BFR system that quickly became the tool of choice for thousands of users around the globe. Since 2017, we’ve been proud to call some of the best athletes, coaches, doctors and physical therapists in the world a part of the B Strong family.

As the field continues to develop, we are committed to using science, engineering, education, and our strong connection with the professional rehabilitation and sports training community to continue to make this highly-effective technology more accessible.

After first being skeptical of BFR, Jim Stray-Gundersen, MD, tested it and was quickly amazed at its impact on fitness, health, lean body mass and muscle/strength increase on already highly trained athletes. Dr. Stray-Gundersen knew BFR could have a significant impact on all populations as a means of enhancing exercise and performance if he could make it safe and effective, easy to use, and affordable. 

With Stray-Gundersen's unmatched depth of expertise in medicine, cardiopulmonary and cardiovascular physiology, he continued to research, test, apply, and discovered and identified the key mechanisms that not only made BFR safe, but also made BFR effective, more comfortable and easier to use. 

Board Certified in General Surgery, Stray-Gundersen's background in both academic and athletic platforms gave him a unique perspective of training and performance for all ages and all levels of fitness. 

Stray-Gundersen was on the as research faculty in Cardiology and Orthopedics at the University of Texas Southwestern Medical School in Dallas, Texas for 20 years, and has also worked for 35+ years in Olympic and Professional Sports, focusing on maximizing human performance as a physician, physiologist and nutritionist for United States, Norwegian, German and Canadian National teams in the sports of track and field, cycling, swimming, all types of skiing, speed skating, biathlon, rowing, etc. Stray-Gundersen is co-researcher/author of the pioneering altitude study, Live High/Train Low, a 15-year study that internationally changed how athletes and coaches use altitude training to enhance performance, legally, for which he earned the nomination for Scientific Award from the United States Olympic Committee.

He worked with Special Forces, Marines, Army, Navy SEALs, Delta Force and served as the sports science advisor for the US Ski and Snowboard Association (USSA) for over 30 years, and founded the SG Performance Medicine Center in Frisco, Texas and Park City, Utah.

Jim was extremely dedicated to improving the lives of others through his expertise and knowledge in BFR training. Jim Stray-Gundersen leaves behind a legacy that will live on and grow drastically thanks to his wife, Hollie, sons Sten and Kjell, and his co-founder, Sean.