How Muscles Are Made

While the incidence of, “I don’t want to get bulky” is no doubt WAY down since we opened in 2011, it’s still by far and away the most common statement we get from new athletes when we exchange emails regarding goals (and why anyone who doesn’t deal with in-depth goals discussions probably can’t relate to this). Weights are going to add muscle and make you stronger. It’s undeniable cause and effect, however, whether or not they make you “bulky” is another discussion. Remember that “add muscle” and “make you stronger” are relative statements. We tend to be polar in our projected fears, often failing to realize that the common outcome usually occurs most along the margins, not the extremes. We get a little bit stronger and add a little bit of muscle. But nope. That’s not how we view it. If we touch a weight we’re going to explode like The Hulk. Never mind the host of training, genetic, and nutritional input factors that need to be perfectly aligned for that to occur. (As well as that conceptually false belief of easy muscle growth serving as a philosophical insult to those who have worked hard to intentionally achieve that.) 

In order to “bulk” you need at least 4 of the following items to be present:

  1. A daily caloric surplus of at least 500 calories.
  2. Nearly 1g of protein per pound of body weight.
  3. At least 1g – 1.5g of carbohydrates per pound of body weight. 
  4. Consistently focus your efforts on heavy, high-rep lifting. 
  5. Genetics that favor easy muscle growth. 
  6. You’re eating like shit. 

Let’s address the bulk fear and why it’s ass backwards. For starters, some real talk. You know what’s bulky? Fat. Not muscle. Fat takes up substantially more volume per pound than muscle, so if you really don’t want to be bulky you’d be best served by reducing fat in excess of healthy levels, not the fear of muscle addition. The hilarious irony is that adding muscle onto one’s frame while burning fat will actually reduce bulk, not increase it. So, muscle is your friend, not your enemy.

The Difference Between Strength Training and Body Building

Further, functional strength training is going to create healthy muscle growth. When you reduce the fat on your body, you reduce your body’s ability to store toxins, and when you combine that with an increase in muscle, you increase your metabolism and the ability to burn calories. Muscle is the most calorically active tissue on the body, so the more you have of it, the more calories you burn and the more you can eat. You also make yourself harder to submit, more difficult to attack, and better at life’s functional daily tasks. There is no skill we call upon more in life than strength and the need for muscle.

So there.

I am sure I have a different definition of bulky than you do, so we won’t touch that. We’ll just assume we’re both relatively on the same page of what that means, but my guess is we are miles apart on what creates that, which we will now address. Let’s take a look at how muscle develops in strength training and how it develops in bodybuilding, and why not all rep ranges and lifting loads are created equal.


We define this as, but not limited to:

  • Barbell Lifts @ 75%+
  • 1 – 5 Reps
  • Total Body, Compound Movements
  • For example: 4×5 Back Squats
  • Yields Sarcomere Hypertrophy = Dense Muscle (Not Bulky)


We define this as, but not limited to:

  • Multiple forms of lifting (could be barbells, dumbbells, or other forms) @ 60-75%
  • 8 – 12 Reps
  • Compound Movements + Isolation Movements (where you are targeting a specific muscle group)
  • For example: 4×10 Bench Press
  • Yields Sarcoplasmic Hypertrophy = Bigger Muscle (mixed with proper muscle growth nutrition)

The rep count is what you want to pay close attention to. With strength training, we are in a low-rep environment (1-5 reps) and with bodybuilding, we are in a high-rep environment (8-12 reps). This is the difference between targeting the sarcomere (strength training) and the sarcoplasm (bodybuilding), which is the difference between lean, dense muscle (strength training) and large, growth muscle (body building). The sarcomere is the basic unit of a muscle cell. In it, it holds myofibrils that are responsible for creating tension and contraction (actin and myosin), and it also holds a lot of stuff that’s not responsible for strength and contraction called sarcoplasm (like fluid, glycogen, plasma). (This is all an over-the-top generalization to get across a main point. If you want a thirty minute read that goes into detail with varying viewpoints, you can go here).

The Difference Between Strength Training and Bodybuilding

As you can see with my lovely artwork above, strength training primarily creates density in the fibers. Bodybuilding primarily creates volume in the plasma components. Here is a closer examination of each.

Sarcomere Hypertrophy (Strength Training, ~5R)

Does Strength Training Make You Bulky?


Hypertrophy is derived from Greek, meaning “excess nourishment” or something enlarging. Sarcomere hypertrophy increases the density and the amount of muscle fibers and correlates to increase in strength and athletic performance, without a major increase in the cross-sectional area (size) of the muscle. Strength training in lower rep ranges across compound movements, like a 5R back squat targets muscle growth that results in stronger, but not bigger. In fact, strength athletes absolutely depend on this science because they must continue to increase their strength without going up a weight class. This muscle growth is far more important for athletic performance. With low rep, heavy strength training the muscle gets more dense, gets stronger, but it does not yield a substantial increase in overall volume (i.e. bulk).

Sarcoplasmic Hypertrophy (Bodybuilding, ~8 – 12R)

The Difference Between Strength Training and Bodybuilding

This is muscle growth where the cross-sectional area of the muscle increases but with little to no increase in muscle fiber density. The volume of the plasma between the muscle fibers increases and there is less increase in strength associated with it. These are longer, more high-rep strenuous bouts of resistance training. More traditional bodybuilding practices are theorized to develop sarcoplasmic hypertrophy, which is what we know as the pump, the result of metabolic stress placed on the muscle and results in a non-dense muscle growth. This is not to say that this kind of hypertrophy is void of functional benefit. This can be very helpful for expanding your base for those seeking to get stronger after a certain point. Take a 145 pound female trying to get stronger. After about a year or two, she may hit a plateau with her focus on strength training. At this point, it can be helpful to expand the size of the base in order to continue to develop. This can also be quite helpful for addressing areas of weakness and helping to limit the weak links in an isolated format.

This is not the recommended strategy for consistent strength training, however, as there is such a thing as too much hypertrophy in the realm of athletics and functional fitness. Excessive muscle growth can create slower recovery patterns, and deterioration in speed-strength and speed.


We will shift focus away from general practices and talk specifically to membership about routes they can take to achieve different goals in strength and aesthetics.

Goal: Stronger w/o Significant Muscle Growth

  • Aim to hit the PSC classes on Monday’s, Tuesdays, Wednesdays, Thursdays & Saturdays & maintain a caloric breakeven or deficit.

The Difference Between Strength Training and Bodybuilding

Goal: Stronger w/ Significant Muscle Growth

  • Hit Mondays, Wednesdays & Fridays consistently with a caloric surplus, lots of protein & carbohydrates.

Our preferred form of strength training here consists of squats, deadlifts, presses, cleans & jerks at approximately 75% and above. This will develop functional, aesthetic muscle that results in healthier human beings. From there, it’s up to you on how you want to pull the strings to explore further muscle growth, but the important takeaway is that muscle growth does require precise and deliberate exploration. It’s not an accidental occurrence that happens upon you without your doing.

And remember, the real cause of bulk is body fat above healthy levels. So stop the muscle fear mongering and embrace the healthy addition of it for both your longevity as a living person, and your performance as an athletic person.

Become more. Not less.

-Dave Thomas


Siff, Mel Cunningham. “Strength and the Muscular System.” Supertraining. Denver: Supertraining Institute, 2003. Chapter 1 Print. P. 68.