The Science Behind Muscle Growth: Muscle Hypertrophy, Strength Training, & Muscle Recovery
If you are going to the gym and working with weights to gain some muscle then it’s really important for you to understand the science behind muscle growth because when you understand the mechanism of how muscles grow and how it affects our health, longevity, and metabolism. You can help yourself to optimize your time in the gym and train more effectively than most people do, and also achieve impressive results in a short duration of time.
There are 3 different types of muscles in our body: Skeletal Muscle, Smooth Muscle, & Cardiac Muscle. Each type of muscle tissue in the human body has a unique structure and a specific role. In this article, we are gonna exclusively look only into skeletal muscle because they’re the muscles that connect to our bones and allow us to perform a wide range of movements and functions that results in muscle growth.
They’re around 650 skeletal muscles within a typical human body and skeletal muscles cause muscle contraction when they receive signals from motor neurons. Motor neurons are the neurons that carry messages from our brains to our muscles. So, the better we get at having those signals between our brain and our muscles that tell our muscles to contract, the stronger we become. Let me give you an example that explains motor neurons more in detail:
Me and my friends go to the same gym, we are a group of 8 people and one of my friends is able to lift very heavy weights despite not looking very big and muscular. He’s not the biggest but yet the strongest person in our group and this is because of his ability to activate his motor neurons and contract his muscles better than the rest of us. Have you ever wondered why some powerlifters can be relatively smaller compared to bodybuilders but can lift significantly more weight compared to them? This is the reason behind their incredible strength.
So, these are the fundamental acquaintances that you need to know before diving deep into the article — The Science Behind Muscle Growth: Muscle Hypertrophy, Strength Training, & Muscle Recovery.
Muscle Hypertrophy
Let’s begin with understanding what is muscle hypertrophy and the mechanism behind hypertrophy.
Muscle hypertrophy is the scientific term for building muscle. It refers to an increase in muscle mass by increasing the size of the cells or tissues in response to various stimuli.
When we train, we create little micro tears within the muscle cells that we use and the recovery process essentially rebuilds these tears to make them grow back bigger and stronger. So, the more muscle fiber you activate in response to various stimuli, the greater your chances of improving your muscle hypertrophy.
Our muscles adapt to the pressure that is placed upon them. That is the reason why increases in strength and muscle mass take place when we work out consistently and apply pressure on specific areas of our body. Now let’s look at the science behind muscle hypertrophy.
Muscle growth happens whenever the rate of muscle protein synthesis (MPS) is greater than the rate of muscle protein breakdown(MPB). Let me explain what this means: Muscle protein synthesis is a naturally occurring process in which protein is produced to repair muscle damage caused by intense stimuli through any physical activity or exercise. This entire muscle protein synthesis process takes place because of mTOR.
mTOR stands for Mammalian Target of Rapamycin. What mTOR does is it controls the growth and production of protein in various types of cells in response to stimuli, including muscle cells. So, when we work out, mTOR gets activated and uses the muscle protein synthesis process to repair the muscle damage that is caused by lifting/training with weights. That’s how the enlargement of muscle fibers (hypertrophy) relies upon mTOR signaling.
There is also an opposing process that counteracts muscle protein synthesis (MPS) known as — Muscle protein breakdown (MPB). MPB is the process of breaking down muscle proteins into amino acid blocks due to protein loss that happens during exercise. The breakdown of muscles may sound negative, but it is a necessary part of building muscle because when muscles are damaged, they will build back larger, as long as we consume enough calories and protein to repair and grow the muscle tissue.
The whole point of MPS & MPB is: Muscle protein synthesis (MPS) is the process of building up amino acids (the building blocks of proteins) into new proteins. Whereas muscle protein breakdown (MPB) is the process of breaking down muscle protein into amino acid blocks. So, muscle growth happens whenever the rate of muscle protein synthesis (MPS) is greater than the rate of muscle protein breakdown (MPB).
If the rate of muscle protein breakdown (MPB) is greater than the rate of muscle protein synthesis (MPS) then it results in muscle loss. That’s how MPS & MPB control the muscle growth and muscle loss of our body.
And, there are also 2 types of muscle hypertrophy: Myofibrillar hypertrophy & Sarcoplasmic hypertrophy.
Myofibrillar are long cylindrical thread-like structures that lie parallel to the muscle fiber that is responsible for muscle contraction. Myofibril is formed by 4 complex proteins known as: myosin, actin, tropomyosin, and troponin. These four complex proteins are arranged into a functional unit called a sarcomere that is present inside myofibril. When you are flexing your muscles you are contracting thousands of small muscle fibers. Each of those fibers is a muscle cell that is comprised of myofibrils, each consisting of repeated sections of sarcomeres.
As we already know, when we are training with weights, we create little micro tears within the muscle cells that we use and the recovery process essentially rebuilds these tears by Muscle Protein Synthesis (MPS). So, during the MPS process, the protein that is produced to repair the muscle damage also adds additional myofibrils into our muscle cells and makes them become larger in size which results in muscle hypertrophy. And, the muscle hypertrophy that is caused by an increase in the number and size of myofibrils is called Myofibrillar hypertrophy.
Sarcoplasmic is the fluid surrounding the myofibrils in our muscles. It contains ATP, glycogen, creatine phosphate, and water. In simple words, sarcoplasmic is everything in a muscle fiber that is not myofibrils. It is a process of increasing fluid in our muscles to increase their size(hypertrophy). And, the muscle hypertrophy that is caused by an increase in sarcoplasmic fluid in our muscles is called Sarcoplasmic hypertrophy.
The difference between myofibrillar hypertrophy and sarcoplasmic hypertrophy is: Myofibrillar hypertrophy increases strength and speed by activating contractor muscles. It is advantageous for people who want to go for powerlifting, calisthenics, and gymnastics. Whereas, sarcoplasmic hypertrophy increases energy storage and endurance by activating glycogen storage in muscle. This type of hypertrophy is advantageous for people who want to go for bodybuilding.
Strength Training
Strength training involves physical exercises that are designed to improve our strength and endurance by causing muscle tension. When we are lifting heavy weights we are causing tension in our muscles which leads to mTOR activation that helps us in our muscle growth (hypertrophy).
There are numerous strength training techniques out there but no matter how each training is designed, in the end, they are always going to fall into either one of these categories:
Strength Training For Myofibrillar Hypertrophy
Strength Training For Sacroplamsic Hypertrophy
As we already know strength training for myofibrillar hypertrophy is for people who train for powerlifting, calisthenics, and gymnastics. Whereas strength training for Sarcoplasmic hypertrophy is for people who train for bodybuilding.
First, let’s go through Myofibrillar Hypertrophy Strength Training: In myofibrillar hypertrophy training, we must lift heavy weights progressively. Reps in the 5 -12 range with 2–4 minutes rest between each set result in massive changes in myofibrillar volume and density.
Don’t lift weights that you can’t do a minimum of 5 reps per set because gradually increasing either the weight you’re lifting or the number of times you lift it is the key to myofibrillar hypertrophy. SO, LIFTING HEAVIER WEIGHTS PROGRESSIVELY & LONGER REST PERIODS BETWEEN EACH SET IS HOW WE TRAIN FOR MYOFIBRILLAR HYPERTROPHY.
Now, let’s go through Sacroplasmic Hypertrophy Strength Training: In sarcoplasmic hypertrophy training, we must go with higher reps with reps in the range of 10–15 with moderate weights and short rest periods of 45–90 seconds. Slower rep training or muscle superset training are great training patterns that can be used to train for this method. SO, SLOW REP TRAINING WITH CONTROLLED WEIGHTS & SHORTER REST PERIODS BETWEEN EACH SET IS HOW WE TRAIN FOR SARCOPLASMIC HYPERTROPHY.
Muscle Recovery
Working out is important but what we do after our workout session for muscle recovery is much more important than just working out insanely because muscle recovery has a great influence on our results for muscle hypertrophy.
We will only be able to get the best out of our workout sessions when we only have a good muscle recovery session because when we are working out we are stressing our body for fat loss and muscle growth and a muscle recovery session helps our body to relax and recover from our previous workout sessions so that we could train again without carrying the feeling of stress in our body.
Here are a few simple but effective muscle recovery routines that you need to adapt for immediate recovery:
Hydration: Dehydration can affect our muscle's ability to repair themselves because water is what helps thin the blood and move nutrients and oxygen through the body. So, the more water we drink, the easier the cell-repairing nutrients can be brought to the recovery areas in our body. This helps to speed up the recovery time and eradicate the feeling of soreness in our muscles. Hydration also helps in Muscle Protein Synthesis (MPS) process to repair micro tears within the muscle cells that are caused by lifting heavier weights.
Protein Intake: The daily intake of protein from our food is essential as it helps us to increase the rate of muscle protein synthesis (MPS) in our body. And, as we already know muscle repair and growth only happen when the rate of muscle protein synthesis (MPS) is greater than the rate of muscle protein breakdown(MPB). So, to increase the rate of MPS, we need to have 0.8 grams per kilogram of body weight as it helps us to maximize stimulate protein synthesis.
Good Sleep: Sleep has a lot of impact on our muscle recovery and rebuilding process. We go through 4 stages of sleep every night, and during one of these stages, we go through a phase where our blood pressure drops and our body promotes muscle growth and repair. So in this process blood flow increases in our muscles, growth hormone will be released, and cell repair occurs. In simple words, during our sleep, our body goes through repair, rest, and rejuvenation.
Note: To know more about the 4 stages of sleep and how it affects our body and brain. Read the article I wrote about Sleep called: The Science Behind Sleep — Sleep Stages, Sleep Architecture, & Sleep Hygiene.
Rest Days: This is the most highly ignored recovery routine by most beginners who just get started working on their bodies. Most beginners either rest a little or not at all and either way it is their biggest barrier to muscle recovery and growth. Most people believe that muscle growth only happens when they train 7 days a week and put their bodies through constant pain and pressure through training but that is not how you build a better body. And, you are more likely to be injured by training 7 days a week and giving your body enough time to recover.
Our muscles need time to heal so that we could perform better and make progressive growth toward our fitness goals. Muscle growth doesn’t happen when we put our body through pain, muscle growth only happens when we put our body under pressure by training and also by giving ourselves enough time to recover from the muscle damage by eating right good, having good sleep, and better relaxation routines.
Conclusion
The more you dive deep into the science behind muscle growth, the more you keep discovering about your body. But at the end of the day, you don’t need all of that information to achieve your fitness goals. I have done my research for weeks, eliminated all the unnecessary information, and I wrote this article in a way that helps you to understand the essential science behind muscle growth to train effectively and optimize your time in the gym. That has been the end goal of this article from the start. So, I hope this article helps you to get the best out of the time you spend in the gym to make it into the best shape of your life.