Today i start a series of posts on Hypertrophy, to start the series I guess we should discuss what Hypertrophy really is & how it happens.

Hypertrophy is an enlargement of the actual muscle fibres.
There are two ways to create hypertrophy, one is through tension (mechanical stress on the muscle).
The other way is through cell swelling.
Tension causes myofibril hypertrophy, enlargement of the cross sectional area of the myosin & fibrils.
Cell swelling causes sarcoplasmic hypertrophy, as Arnold so famously called it..the pump❗️

Sarcoplasm is the fluid around the muscle, mitochondria, water, creatine, glycogen & capillaries.
It puts great demand on the energetics of the cell, then the cell has to increase its ability to produce energy so it increases the volume of the sarcoplasm to store more of everything which all contribute to
growth but don’t contribute to contraction.
So from a performance stand point the difference between myofibrillar & sarcoplasmic hypertrophy would be if someone has more myofibril hypertrophy they will be stronger (more force) & if they have more sarcoplasmic hypertrophy the energetics of the cell are enhanced & would be better at endurance.

Myofibril is more dense fibres like a power lifter, sarcoplasmic are more rounder like a body builder.
Look at hypertrophy as a continuum, at one end you have maximum load (low reps) you can lift with minimal TUT (time under tension) & at the other the load is less but the TUT & reps increase.

Hypertrophy is a product of load X TUT.
You will hypertrophy at either end but you will hypertrophy for different reasons
Stimulus to the muscle fibres is governed more by the TUT than the reps.

It is worth pointing out though that yes, the 8-12 rep range is considered the hypertrophy rep range to work in if you want to grow but considering you can do an 8 rep set in as little as 10 seconds or up to 2-3+ minutes this shows how much TUT is important to also factor in with your program design as i will discuss further below.

Now that we know this, the next decision to make is what is your actual current goal, do you want to get strong first? or maybe your sport has more of an endurance base or body weight requirement to it, what was your last program supposed to be achieving? again these are all things to consider when designing your new program.

Now that you know TUT is more important than the actual rep number lets look at the different zones you can work in to achieve an increase in either strength or hypertrophy.


0-20 Seconds  of TUT
The load is high in this zone & the TUT is not enough to break down myofibril’s so the training response will be quite limited for hypertrophy (strength phase).
Nervous system will become very effective at recruiting new muscle fibres but won’t hypertrophy as much as a longer TUT.

Once you return to a hypertrophy phase with an increased TUT there will be new muscle fibres to hypertrophy that were not active before the strength phase.
If someone does not want to put on size but needs to increase strength they predominantly should be trained in this zone.



20-40 Seconds of TUT
Myofibril muscle fibres are targeted most in this zone, specifically high threshold motor units.
An athlete that needs to increase strength but needs to also stay fast & have a high power to weight ratio will use this zone often.



40 – 70 Seconds of TUT

Myofibril hypertrophy occurs best in this zone, plus also the intermediate motor units.
This zone is perfect for an athlete or weekend warrior that needs absolute strength without respect to body weight (body builder). All the motor units are worked in this zone. 



70+ Seconds of TUT 
The load is light in this zone, so it wont be enough to stress the Myofibril muscle fibres.
This zone will stress the energetics of the muscle cells in this zone.
Cell swelling – The Pump! ❤️

Training a body builder in the 0-20 second zone will help to improve the amount they
can lift through all the other zones. 

In the coming parts to this series on hypertrophy i will go into detail how to get the most out of each & every training session from every angle including nutrition, optimal body fat %, periodized training programming & de-loading. yes sometimes you need to rest to grow!



Comments are closed.