Blood Flow Restriction Training

[bravenewfictor]

In the spirit of targeting and isolating specific muscles, which I know is something you focus a lot on RRM, have you (or anyone else in here) had any experience with blood flow restriction training? I am currently doing heavy, fairly low rep strength training, but I am looking for a smart solution for adding some more hypertrophy oriented elements into my program. BFRT seems like it has some advantages:
-Fairly time efficient
-Possible faster recovery than with heavier isolation exercises
-Possibly less likely to interfere with strength gains
-Very low risk of accidents, due to low weight being used

This podcast is a good intro to BFRT: https://www.youtube.com/watch?v=KXh2THPc984

I am considering implementing this for some exercises like bicep/tricep work, and perhaps some hypertrophy-work for legs.

[RRM]

The truly effective component of BFRT is lactate accumulation.
You can do that by restricting blood to the veins, but is far more simple to do it differently.
It's something i do all the time. Instead of using heavy weight, you need to use very light weights.
If you use heavy weights, you primarily use ATP and CP for energy, and once that is used up, the weights are too heavy to carry on. As a result your muscles will feel tired, but it's very hard to get'that burn'.
If you use light weights, you will be mainly using glycogen anaerobically. This always results in lactate accumulation, and then you can make it burn as much as you can bear.
The weights need to be light enough that you feel nothing for the first minute, and heavy enough that it starts burning after 90 seconds.
After those 90 seconds, the lactate really starts accumulating, and that is where the exercise truly begins.
Continue doing reps despite the burn. If you cannot stand the burn anymore, stop for 1 second maximally, and then continue.
Repeat until completely wasted.
That takes 10 minutes maximally. No need for restricting blood flow. It works like a charm and is very much time efficient.

[bravenewfictor]

I would argue that there very well might be other mechanisms, such as cellular swelling, that makes restricting blood flow more effective than just lifting to failure with quite light weights with no restriction. Several other mechanisms have been proposed.

Also, if the lactate accumulation alone was a major trigger for hypertrophy, I think we would see way more muscular physiques in endurance sports, and that is not really the case. Some studies (not all) shows that a relatively high percentage of 1rm is more effective for hypertrophy than lower loads (and higer rep ranges).

Thirdly, training to failure the «old fashioned» way is very depleting and damaging to the muscle, and generally one would have to wait quite some time before hitting the same muscle again. This is why typical bodybuilder programs (tons of volume, high frequency) dont tend to work very well when the athlete is not on drugs to boost recovery. With blod flow restriction, at least in theory, you get the same muscle building signaling, without the same degree of muscle damage. This will, in theory, allow you to hit the same muscle more often, thus giving you more hypertrophy within a given time frame.

[RRM]

I would argue that there very well might be other mechanisms, such as cellular swelling, that makes restricting blood flow more effective than just lifting to failure with quite light weights with no restriction. Several other mechanisms have been proposed.

Sure. To me it just seems a lot of hassle.
You don't need that hassle to maximize lactate exposure.
It's not lifting to failure. Lifting to failure is quite specific for ATP / CP training methods, usually lasting less than one minute (not maximizing lactate accumulation).
Instead, it's lifting to pain (maximised lactate accumulation), in which the true exercise (lactate accumulation) only starts after 60 to 90 seconds, until about 3 minutes.

Also, if the lactate accumulation alone was a major trigger for hypertrophy, I think we would see way more muscular physiques in endurance sports, and that is not really the case.

All endurance sports are about aerobic utilisation of sugars and fats. In endurance sports, the training programs are specifically designed to keep lactic acid levels low. Endurance sports always last much longer than several minutes.
I'm talking about anaerobic utilisation of glycogen. This method is aimed at maximizing lactate accumulation, peaking between 90 seconds and 3 minutes.

Some studies (not all) shows that a relatively high percentage of 1rm is more effective for hypertrophy than lower loads (and higer rep ranges).

To compare ATP/CP storage training vs lactate accumulation, it's not enough to compare fewer vs more reps.
If you do more reps, but still train to fail, and don't specifically train to maximise lactate, yes, it may certainly be less effective.
But this goes beyond less versus more reps. This is about the difference between training ATP and CP storage versus maximizing lactate exposure.
And that difference goes further, with the need for longer rest periods and isolation exercises.
To compare that, you need to specifically test that, and not just fewer vs more reps.

Thirdly, training to failure the «old fashioned» way is very depleting and damaging to the muscle, and generally one would have to wait quite some time before hitting the same muscle again.

This method is not training to failure. It's not the bodybuilding way.
This method is training to pain/burn.
It is less damaging to connective tissue, tendons etc, as the load is far smaller.
But, yes, it is very damaging to the muscle, even more so than the old fashioned way. Its exactly that damage that stimulates hypertrophy.
And yes, you are right. That indeed means that you need to rest each muscle thoroughly. You need to wait at least one week before you should exercise that same muscle. That is why in this method isolation exercises are required. This enables you to totally leave other muscles alone while exercising a different muscle. Exercises are designed in such a way that the supporting roles are absolutely minimized. In typical bodybuilder exercises, multiple muscles are trained (one main muscle, plus supporting roles)

With blod flow restriction, at least in theory, you get the same muscle building signaling, without the same degree of muscle damage.

Actually, with blood flow restriction, you disable the possibility to deport lactate, thus increasing the exposure to lactate, which is the damaging aspect.
Normally, accumulating lactate is partially dumped in the blood to get oxidized to pyruvate by cells in the heart, or other well-oxygenated muscle cells, or it is converted to glucose in the liver. That path is blocked when restricting blood flow. Thus active muscle cells need to do the oxidation all by themselves. Hence more lactate accumulation.

[bravenewfictor]

Interesting points RRM!

Since my goal is more overall muscle and strengt gains, training in a way that makes me unable to repeat that exercise for a week is not ideal. BFRT might enable you to train every muscle way more often, yielding more gains in total.

Also, the guys behind the Mindpump podcast talks a lot about 'trigger sessions'. What they do, is that they do low intensity exercises on rest days. The idea is to both boost recovery (by increasing bloodflow to the tissue) and to send a small 'muscle building signal', re-enforcing the stronger signal that was sent during a more heavy/intense workout the prevoius day. In theory, this allows you to somewhat increase the frequency of the main workouts, as well as improve the overall effect. Could be worth looking intoleranse

[RRM]

BFRT might enable you to train every muscle way more often, yielding more gains in total.

Actually, gain is the result of triggers plus rest.
The trigger causes damage, and rest enables compensatory growth.
If you exercise the same muscle too soon, the compensatory effect will not be maximal. Thats called overtraining.
If, on the other hand the rest period is too long, then you are undertraining.

How much rest you need depends on how much damage (trigger) is caused.
More damage = more rest needed.
If you want to train more often, each exercise needs to inflict less damage. If not, you are overtraining.
If BFRT enables you to train more often, you either overtrain, or train less intensively.

training in a way that makes me unable to repeat that exercise for a week is not ideal.

The reason that this recovery requires a week, is because the intensity is extreme.
When less damage is caused, less recovery time is required. So, it's not the method, but the intensity that determines how much recovery is needed.
You could also train each muscle twice a week, but only with lower intensity. If not, you will be overtraining.

What they do, is that they do low intensity exercises on rest days.

Yes, that's recovery training. It's a well documented, decades old concept.

[bravenewfictor]

The point with the BFRT is to send the same signals for growth, without the same degree of damage to the tissue. It is not only 'damage' that triggers hypertrophy, that is a simplification. Steroids are not inflicting damage, but mimicks one of several signals that the body would produce naturally when training. Localised release of growth factors is one proposed mechanism, and restricting bloodflow further enhances the ability for these molecules to interact with receptors.

The idea is therefore to get the same degree of hypertrophy, with a lesser need for recovery. This in turn allows you to increase frequency without overtraining. Lets say you can send the same signal to grow the muscle twice per week, instead of once, that would in theory double your gains.

[RRM]

The point with the BFRT is to send the same signals for growth, without the same degree of damage to the tissue.

There are 2 causes of muscle damage:
1) mechanical (loading)
2) chemical (lactate)
Training the same weight with BFRT vs normal will indeed be more effective.
In both exercises the mechanical loading may be the same, but in BFRT the damage caused by lactate will be greater, because in BFRT the deportation of lactate is inhibited.

So, comparing BFRT vs normal, the effectiveness of BFRT will be greater, despite similar mechanical induced damage. That is because in BFRT the lactate induced damage will be greater (similar to my method).

Steroids are not inflicting damage

No, but the release of steroids and growth factors is evoked by the damage, either chemically or mechanically induced.
If it is not damage, through which other pathway is their release stimulated?

Localised release of growth factors is one proposed mechanism,

How exactly are their levels elevated, other than by being triggered by mechanically or chemically induced damage?
What pathway?

restricting bloodflow further enhances the ability for these molecules to interact with receptors.

These growth factors are not released DURING the (catabolic) exercise.
They are released AFTER the exercise, during the anabolic recovery phase.
Thus the restricted bloodflow has no influence on those growth factors whatsoever.
First you exercise, and then you recover. They are separate.