Blood Flow Restricted Training – what’s that?
Article by Dr. Darrell Menard – (Former RMC Physical Education Officer)
Q: I enjoy weight training and have made significant gains since joining the CAF. I’m always looking for new training strategies and while deployed I was introduced to something called blood flow restricted training. Have you heard of this type of training and could you comment if it works and if it’s safe? Sgt. Strong
A: Dear Sgt. Strong: Blood flow restricted (BFR) training is also called occlusion or Kaatsu training and has been around for many years. Its claim to fame is allowing people to make training gains doing low resistance exercise.
BFR training involves using a tourniquet to restrict blood flow to the arms or legs. The pressure to the limb must be strong enough to stop the return of venous blood from the constricted limb but not strong enough to stop arterial blood flow. This can be difficult to achieve as the desired pressure is highly individual. With the limb constricted, the person does resistance exercises at 20-30% of their 1 repetition maximum. People typically do 3 sets of 20-30 repetitions at this low resistance. The theory is that doing low intensity training with restricted blood flow allows people to make the same training gains they would get from doing high intensity training.
Does BFR training work? For people like yourself who can do higher intensity training, the research clearly shows BFR training offers no advantage and may even be less effective than high intensity training. Some rehabilitation programs have used BFR training and found it helpful for people who because of disease or disability can’t do higher intensity training with their arms or legs.
Is BFR training safe? Very little research has been done regarding the safety of BFR training but there are some significant concerns:
- Reducing blood flow to working muscles activates a reflex that can put people with high blood pressure, heart disease and poor circulation at increased risk of abnormal heart rates, heart attack, stroke and sudden death. This is concerning because many people have these medical conditions and don’t know it;
- We have no idea if there are potential health risks from the long term use of BFR training;
- There is no standardized way to determine the ideal constricting pressure for anyone doing BFR training and using excessive pressures could damage blood vessels, muscles and tendons and could also trigger life threatening blood clots; and
- This training approach is not recommended for people with the following conditions: pregnancy, a history of blood clots, poor arm and leg circulation, varicose veins, high blood pressure, heart disease, limbs that have had their lymph nodes removed, abnormal heart rates and people who are on medications that increase the risk of clotting.
The bottom line: BFR training will be a waste of time for you and we are uncertain about its safety. The potentially dangerous cardiovascular responses to this training technique are such that further research is needed to determine if it can safely be used by people who can’t do high intensity training because of disease or disability. Train smart – Exercise is medicine
Dr. Darrell Menard OMM MD, Dip Sport Med
Dr. Menard is the Surgeon General’s specialist advisor in sports medicine and has worked extensively with athletes from multiple sports. As part of the Strengthening the Forces team he works on injury prevention and promoting active living.
Strengthening the Forces is CAF/DND’s healthy lifestyles promotion program providing expert information, skills and tools for promoting and improving CAF members’ health and well-being.