Blood Flow Restriction Training, or BFRT, is a training method that places a cuff or band around a muscle of interest, inflate it to reduce blood flow and then perform resistance exercises at low intensity (20-30% maximal) but high number of repetitions (15-30 repetitions/set).
The first question that comes to mind is…
Why do restrict blood supply to muscles when is a key factor for performance?
Restricting blood flow to the muscle being trained limits the level of oxygen available to its cells. This hypoxic environment increases the anaerobic metabolism and the production of lactate. MORE lactate translates in MORE fatigue, even during low intensity workouts.
But then arises another question…
Why having a more tired muscle will improve my training?
The adaptative changes to the muscles during BFRT will be similar with those occurring with high intensity exercises.
When comparing 6 weeks training programs including high intensity, low intensity, high+low intensities with BFRT and low intensity with BFRT, the high intensity group and those including BFRT produced similar results in muscle endurance.
Greater and faster fatigue on the muscles, giving the athlete enough time to recover, allow muscles to develop and adapt more quickly.
How do the BFRT works?
Although the technique has been in use since the 1970s there is still much to be studied.
Some of the reasons behind the beneficial effects of BFRT may be due to:
- Increased release of Growth Hormone and lactate, which drive muscle growth.
- Development of additional blood vessels.
- Increase of the size and number of mitochondria, that are the energy “factory” of cells.
- Increase of the amount of protein that can be used by the body.
How about BFRT in runners?
Among runners BFRT causes “slow-twitch” Type I muscle fibres, which need oxygen as fuel, to become less active. The resulting outcome is the recruitment of “fast twitch,” Type II muscle fibres, capable of turning a runner faster.
Who else can benefit from BFRT?
Besides the already mentioned benefits on performance after including BFR training sessions on your schedule there are other populations to benefit from this technique:
- Injured athletes
After an injury there must be a healing process, in which heavy loads and high intensity sessions are inappropriate. BFR helps to attenuate muscle atrophy in a low-load environment while speeding up recovery.
- Post operative patients
After procedures such as Achilles repairs or knee replacements BFRT techniques allow muscles around the treated area to keep working without much strain.
- Old people
Ageing often involves limitations of mobility. It is in these situations that BFRT is useful, keeping the muscles working in arthritic conditions or people with difficulties to raise from a chair.
Thus, it is worth noting that even wearing a cuff at low pressure WITHOUT EXERCISE can be beneficial.
Who could have BFRT contraindicated?
People with vascular insufficiency or cardiac conditions should be careful with this technique and look advice from a physician before trying it.
Did you have any experience using these techniques? If so, we would love to read your opinion. Anyway, we hope this information was useful for you.
Video from Blood Flow Restriction Therapy After Knee Surgery: Indications, Safety Considerations, and Postoperative Protocol. NN DePhillipo et al. 2018