The purpose of this article is to guide you through the use of blood flow restriction training. This method of training is useful for muscle building, attenuating muscle loss during rehabilitation, reducing the effects of sarcopenia and improving functional ability in the elderly.
The reason why I’m writing about it is two-fold: Firstly it is to properly inform those that use this training method, but don’t quite understand its underpinning principles.
Secondly it is to introduce it to those who haven’t heard of it or tried it before.
This article will give you a step by step guide on how to integrate BFR training into your training safely and effectively.
Traditionally, training advice from bodies such as the ACSM have always advocated a mid-load range of 75% 1RM in order to build muscle. More recently that advice has been questioned. Whilst load is without a doubt an important variable in increasing the hypertrophy response, there is emerging evidence to suggest that muscle size can improve across a broad spectrum – in particular lighter loads.
One such method – blood flow Restriction training (BFR) – is an example of how using lighter weights can invoke improvements in muscle size.
The premise behind BFR is that you wrap a band, pressure cuff or tourniquet at the proximal (above) end of the muscle as a way of restricting blood flow. Original research used specific pressurized bands called KAATSU bands that could be set at specific pressures.
When done effectively, the pressure allows blood into the muscle via normal arterial blood flow, however due to the position and nature of veins, blood flow is restricted* from leaving. This leads to a surplus of blood within the muscle that results in longer nutrient perfusion time and net blood volume (AKA ‘the pump’).
*blood flow is only restricted not stopped which is why referring to this method as ‘occlusion‘ training is somewhat misleading.
The swelling effect of BFR initiates the build up of metabolites (lactic acid, hydrogen ions etc.) that trigger hypertrophy. The impact of this effect is that the central nervous system recruits and subsequently fatigues larger, anaerobic motor units. This is also important in the hypertrophy response.
The main positive outcome in healthy individuals is that of increased muscle mass. Cell swelling, hypoxia and lactic acid stimulated growth factors all contribute to this process. In this instance it is the mToR and NOS1 pathways that are said to be the triggering hormonal cascades that result in new satellite cells being activated (muscle stem cells).
BFR has also been seen to benefit clinical populations too. The use of tourniquet-based training post-ACL reconstruction has been found to attenuate muscle loss over a 3-month period  as well as other injuries and illnesses. Bodybuilders who have injured themselves or broken bones have found that using restricted training can continue training without any effects on bone recovery .
Lastly, the stimulation of the mToR pathway is useful for offsetting age-related muscle loss (sarcopenia) as increased protein synthesis helps to reduce loss of muscle mass. The fact that sarcopenia is associated with increased falls, all-cause mortality and loss of functional capacity, this is particularly useful.
The original KAATSU bands were used in early lab studies and gave a very controlled restriction effect which could be replicated each time to exact parameters. Whilst very high quality and pretty sophisticated, these bands are unfortunately very expensive. Instead, you can use a normal lifting wrap – or even better an elasticated tourniquet (more comfortable, easier to put on and take off).
When you tighten the band you should aim for a 6-7 (if 10 was the maximum amount of tightness and discomfort). The band itself needs to be placed on the proximal aspect of the limb. This is typically the part of the muscle nearest the center of the body e.g for the biceps you’d place the band at the point where the muscle connects to the shoulder (the axillary fold).
BFR is typically performed with light loads of 20-50% 1RM. this would usually allow 25 or more reps without a restriction device. Unless injury doesn’t allow it, aim for 40-50% 1RM to maximize motor unit recruitment.
Due to the load being so light, this method is able to increase muscle size without over-taxing the connective tissue at the trained limb. This makes it applicable to not only bodybuilders but rehabilitating athletes who wish to preserve muscle during a recovery period. There are a number of ways that you can perform BFR but the more traditional and well-known method is that used by Loenneke .
1. You’ll complete 1 x 30 reps, then 3×15 reps
2. Keep rest times minimal – 30-45 seconds between sets
3. Keep the bands on until ALL 75 reps have been completed.
4. Aim for a quick rep speed – around 1 second up, 1 second down. With such a low weight there’s no need to be over-controlling. You’re trying to pump as much blood into the muscle as possible.