Ok, functional hypertrophy is not real … but it is.
Functional hypertrophy is typically described as a gain in muscle size that leads to an equivalent gain in physical capacities. And is traditionally associated with gaining muscle mass via fairly low reps and heavier weights (5-8 reps/set most of the time). And it comes from the theory of sarcomere (contractile elements of the muscle fibers) hypertrophy vs sarcoplasmic (increase in the non-contractile elements of the muscle) hypertrophy.
More and more work seems to contradict this theory, showing that muscle mass gained via sets of 3 reps or 20 reps is structurally the same. Thus if you build 10lbs of muscle it will be the same tissue regardless of the type of training you did to get there.
Yes but if I trained mostly using sets of 5 and gain 10lbs of muscle my strength will go up more than if I gain the same 10lbs using sets of 15+ reps.
True. At least in the short term. But that is likely not due to differences in the type of muscle gained but simply because when you are using lighters weights you do not improve the nervous system as much. And the nervous system is at least as important as muscle mass when it comes to force production. Therefor it is not surprising that one would gain more strength, for the same amount of muscle growth, when utilizing lower reps/heavier weights.
There is also the possibility that heavier weights develop the fast twitch fibers more than the slow twitch fibers and that high reps (more than 15) work more the intermediate fibers (VERY high reps hitting more the slow twitch fibers). Thus leading to more strength and power improvements.
“Functional hypertrophy” probably does not exist as a “type of gain”… you won’t build 5lb of non functional muscle or 5lbs of functional muscle depending on how you train. The difference in performance gains is not dependent on the type of muscle being built but rather on how much CNS improvement you stimulated.
So we can say that there IS such a thing as “functional hypertrophy training”; a type of training that directly increase strength and size to the same extent. But that is due to stimulating a high level of CNS improvement along with the muscle growth. And yes, that requires the use of heavier weights.
Does it matter to the non-athlete? Sure.
There are many ways to stimulate muscle growth.
- Creating muscle damage
- Increasing the release of local growth factors
- Activating mTOR
- Releasing lactate
- Increasing stem cell levels
As such you can stimulate muscle growth by many different training methods. And for best results it is best to use more than one method (not necessarily in the same training session or even training phase). So “functional hypertrophy training”, stimulating growth via fairly heavy weights and lower reps will work via a different mechanism than doing pump work or slow eccentrics (for example).
Not all types should use the functional hypertrophy zone to stimulate growth. Types 2B and 3 will do less of it than the other types. But it is still used somewhere in the training year for maximum results.