The Bigger They Are...

Fitness culture loves buzzwords - verbal forms of neon signage.

I’ll refrain from attempting to list them all, lest I turn this article into a novel.

Here’s the point: a recurring sort of buzzword, perhaps one of the originals, is the term “hypertrophy.” This term is, unsurprisingly, somewhat nebulous and loosely applied; I’m interested in taking a deeper look.

“Hypertrophy,” according to Merriam-Webster, is an “increase in bulk (as by thickening of muscle fibers) without multiplication of parts.” In essence, it’s a term that people like to use for “getting bigger muscles.”

Traditionally, “hypertrophy” training has been relegated to strict parameters - adhered to by followers of conventional literature and bro-science, alike.

Sets of eight to twelve reps, training to failure, “feeling the burn…”

All of this is fine and well - but, perhaps - it doesn’t capture the entire picture.

The traditional, “bodybuilding” application of hypertrophy is likely… sarcoplasmic.

I’ll elaborate.

Hypertrophy, as many of you know, is generally divided into two “camps:”

A.) Myofibrillar Hypertrophy: An increase in the density and volume of myofibrils, within a muscle fiber; traditionally associated with heavy strength training.

B.) Sacroplasmic Hypertrophy: An increase in sarcoplasm (fluid) within a muscle, as opposed to myofibrillar development (contractile tissue).

Sarcoplasmic hypertrophy is more “traditional,” in that people generally associate it with bodybuilding training and “show muscles.” It’s often regarded as inferior to its myofibrillar counterpart, when discussed by strength coaches.

Myofibrillar hypertrophy has become its own sort of buzzword. Currently, it’s touted as something more “functional” or useful, as it is associated with an increase in contractile tissue within a muscle. Denser, more voluminous muscle fibers = more force production, is the idea.

In reality, and perhaps unfortunately, there is not always such a clear delineation and hierarchy between these two brothers.

First off, let’s talk about “functionality.”

Yes, myofibrillar hypertrophy is generally associated with an increased capacity for maximal force production - relative to sarcoplasmic hypertrophy. But, the idea of sarcoplasmic hypertrophy being useless, or simply for show, is naive at best.

When myofibrils increase in density, the muscle fibers that they comprise increase in the ability to produce contractile force - all else equal. This is understandably useful for any activity that requires strength, which - put, bluntly - is every form of physical activity. 

For this reason, I recommend a base of maximal strength training for almost every athlete - the extent to which this training is pursued is, of course, determined by individual needs.

So, why pursue some sort of sarcoplasmic development - when myofibrillar hypertrophy makes us stronger, and to some extent, bigger?

Sarcoplasm isn’t dead weight - it contains glycogen, which can be indirectly converted to ATP.

ATP allows you to move, and produce force.

Sarcoplasmic hypertrophy isn’t just for Arnold; it’s a mechanism to increase the volume of on-board fuel, within the muscle.

At this point, I hope that we’ve established that there isn’t “good” and “bad” hypertrophy; the waters have been muddied, so we may need to dig deeper.

Like most things in fitness, and perhaps life, the question of hypertrophy is a Goldilocks problem. What is “just right” for you?

It is difficult to develop these aspects of hypertrophy in complete isolation of each other - there are numerous variables at play that extend far beyond prescribed rep ranges and intensities.

Where there is one, there is the other; it’s a gradient of involvement.

In an effort to provide something more actionable, which is the intent of this article, let’s consider the following guidelines:

If your interest is in developing near-maximal contractile force, prioritizing myofibrillar hypertrophy, you may benefit from…

• Primarily higher intensities (80-85%+ of 1RM).

• Utilizing movements that facilitate heavy loads (Deadlifts, Back Squats, etc.)

• Utilizing movements that facilitate short, intense efforts (Olympic Lifts, etc.)

• Rep ranges of ~1 to 5.

• Longer rest times (3 to 5+ minutes).

• Lower total volume, to facilitate higher intensities.

If your interest is in developing muscular endurance or muscle size, via sarcoplasmic hypertrophy, you may benefit from:

• Primarily low to moderate intensities (<80% of 1RM).

• Rep ranges of 8 to 50+

• Shorter rest times.

• Higher total training volume.

If your interest is in concurrently developing both, something like Interval Weight Training (Dr. Pat O’Shea) may be useful to you.

Of course, these are just cursory guidelines. Other variables are always at play, including hormonal/metabolic states, nutrition, sleep hygiene, external stressors or training stimuli, and countless additional factors.

In summary…

If you want to get maximally strong, and increase volume/density of myofibrils: lift heavy things, rest a long time between efforts, and prioritize high intensity movements.

If you want to lift things, over and over, for longer periods - and/or “get big:” lift low to moderate loads, for a lot of reps, within comparatively short rest intervals. Prioritize increasing total volume over total intensity, within a given period of work.

If you want to do both, combine moderate-to-heavy loads with hard anaerobic efforts, calisthenics, and traditional “bodybuilding” movements; again, see the work of Dr. Pat O’Shea for more on that.

There’s a lot of ways to skin a cat.