If you think that a specific diet or exercise regime will guarantee muscle growth, you’re only half right. When we switch our perspective from the ‘macro’ to the ‘micro,’ we can fully understand what it takes to put on mass. Sadly, your muscles don’t magically sprout after you lift a dumbbell or drink a protein shake. There’s much more to it than that. This is a complex (and slow) sequence of recruiting cells, releasing growth factors, and fusing microscopic parts.
To use a metaphor, think of a single muscle fiber as a tree and your entire musculoskeletal system as a forest. By investigating the function and needs of the individual roots, we can start to see what it takes to help the whole forest thrive.
A Deep Dive Into the Muscle
Before diving in, please know that this system is extremely complex. We’re only scratching the surface of what’s really going on, but I sincerely hope it opens up a new perspective for you.
Unlike some cells, muscle fibers are unable to reproduce, so they must get creative. Fortunately, they show tremendous plasticity in response to mechanical load, stretch, and injury. Satellite cells are the stars of the show, being responsible for muscle adaptation and regeneration. After an exercise bout, they split, form a myotube (a small building block of a muscle fiber), and fuse with existing fibers to build mass.
It should be noted that hypertrophy (muscle growth) is based on adding to existing muscle fibers, as opposed to creating new ones. If you ever hear a trainer tell you that you’re “growing new muscle fibers” after a workout, please know that there is no evidence of this occurring in humans (yet). Additionally, these adaptations happen during the rest phase, not during exercise!
Although work from Jackson et al. has shown evidence that hypertrophy can occur independently of satellite cells, they still have a direct role in speeding up the process. The question is, what can we do to guarantee this growth will occur? How can we maximize our gains based on this physiological understanding?
What It Takes to Achieve Gains
In maintaining this microscopic lens, the basics of muscle growth lie in the balance of protein synthesis and protein degradation, along with cell turnover rates. Although the mechanisms of growth are complex, your job is actually quite simple. This process is optimized by functional overload through exercise and subsequent protein intake.
In short, continue lifting heavier weights to damage more total muscle fibers, allow for ample recovery, and fuel your body throughout.
By applying a load greater than you’ve experienced before, you’re literally changing the chemical construct of your muscles. In a gym setting, you may need to go to 'failure' with your reps to achieve this reaction. This will lead to the activation of growth factors, and yes, satellite cells.
This metabolic stress creates the ‘pumped’ look when your muscles become larger post-workout. This is due to an addition of muscle glycogen which helps to swell the muscle along with connective tissue growth (a temporary but satisfying phenomenon). Exercise also helps with testosterone release, stimulating growth hormone responses by increasing the presence of neurotransmitters at the damaged fiber site, which can activate tissue growth.
In summary, exercise triggers your muscle synthesis, while proper nutrition finishes the job. Unsurprisingly, this happens at different rates for everyone. Muscle growth is dependent on many factors including sex, age, hormones, and genetics. This tissue growth is most rapid at a beginner level, and (generally) tends to decrease relative to one’s developing physique. This is all to say, there will be road bumps along the way!
The more progress you make, the harder you have to work.
As you continue your exercise journey, remind yourself that growth is transactional. Give your muscle fibers a new stressor, and they’ll adapt your tissues to produce muscle gains. Revert to your comfort zone, however, and these cells will lie dormant, rapidly halting your progress.
This is a relentless process that takes hard work, there’s no getting around it. You must be consistent. You must get in the volume. You must avoid injury. If it was easy, everyone would be doing it right?
Ironically, the controversial adage of “No pain, no gain!” appears to be scientifically proven… well, at least in a sense.
Now go activate those satellite cells and achieve some gains!