When people talk about “gains”, they are talking about the process of hypertrophy.  Hypertrophy is the term used to describe an increase in muscle size because of training.  That being said, hypertrophy is a polarizing topic that is riddled with several myths and misconceptions.

Each muscle fiber is composed of several myofilaments, contractile units consisting of actin and myosin proteins.  And our muscles will respond and adapt to the stress they are put under through resistance training.  When a muscle is not used it will atrophy, reducing the size of the muscle fibers and the amount of proteins that it contains.  However, when a muscle is forced to work under mechanical and metabolic stress, it will adapt and grow bigger to meet the work demands.

Hypertrophy Vs Hyerplasia

Hypertrophy is not to be confused with hyperplasia, which is an increase in the number of muscle cells.  While more research is needed to understand the developing more muscle cells, it appears that hyperplasia may only contribute to less than 10% of muscle growth.  But through hypertrophy, muscle cells can increase in diameter the size by adding new actin and myosin proteins to the existing myofilaments.

Research has shown that to maximize absolute strength, exercises should consist of low repetitions at intensities above 85% of the 1-repetition max (1RM).  At the other end of the strength continuum curve, to maximize muscular endurance, exercises should consist of a high amount of reps at lower intensities (below 60% of the 1RM).  The middle of the curve and how it relates to hypertrophy is much less clear.

Hypertrophy In Muscles


Hypertrophy training can be initiated regardless of the intensity and repetition ranges being used

Traditionally, 8-12 repetitions of an exercise at intensities around 70-75% of a 1RM have been recommended for hypertrophy training.  While this may result in hypertrophy, increases in muscle size are not exclusively connected to this magical formula of weight and repetitions.  If enough total volume of work is completed, hypertrophy training can be initiated regardless of the intensity and repetition ranges being used.  The total volume of work can be calculated as the amount of weight intensity times the number of sets times the number of reps.  Your body will adapt to demands of your work completed regardless if you are doing a heavy bench press or push-ups.  Your muscles can not distinguish between the two.

Total Volume = Weight x Intensity x Sets X Reps

In 2010, the Journal of Strength and Conditioning Research published that hypertrophy is the result of muscular tension and metabolic stress.  Muscular tension is the product concentric and eccentric contractions to recruit the maximum number of muscle fibers.  Metabolic stress involves training with moderate to high intensity and low periods of rest to induce muscular fatigue.

Hypertrophy And Genetics

While all muscle fibers can undergo hypertrophy, the amount of muscle that your body hold onto is largely due to your genetics.  Your bone structure, the number of muscle cells you are born with, and even your hormone levels are all predetermined to a certain extent.  You can maximize your genetics, but you cannot change them.

While many people fear starting a resistance training routine for fear that they might look “bulky”, adding muscle mass is a slow process with multiple variables.  Unfortunately, social media, the steroid culture surrounding bodybuilding, and even the movies have given the illusion that it is easy to bulk up quickly through working out.

What Are The Best Workouts To Promote Hypertrophy

The best workouts are always the ones that you complete.  Too often people start a workout program only to stop training shortly after.  For me this meant it had to be simple, fun, and and fit into my busy lifestyle. I workout at home or at the gym 5-6 days a week for about 40-45 minutes.  We have 3 kids and blocking off a few hours to go to the gym each day for my personal workouts is just not realistic.  Life is too busy. But I can always find a half hour during the day to fit it in my schedule.

The best workouts are the ones that get noticeable results.  I would say my genetics are “average” at best.  I don’t have a build that will ever let me put on a large amount of muscle while staying lean.  But hypertrophy training has given me the confidence to like what I see in the mirror or to have my shirt off at the beach without feeling embarrassed.

Starting A Hypertrophy Program?

The best way is to answer a few questions and I can guide you in the right direction.  When you are ready to get started I will be here to help you every step of the way.

What Do I Teach Students About Hypertrophy?

The topic of hypertrophy is a very polarizing issue when we go into the weight room in my physical education classes.  Unfortunately there are a lot of myths and misconceptions generated by “bro-science” and the bodybuilding culture when it come to hypertrophy.

Here is the assignment I use in my classes to explain the science behind hypertrophy.