Here’s a guide on skeletal muscle hypertrophy, that will explain the basic concepts in a simple way anyone can understand.
Everyone knows that your muscles get bigger by lifting weights (and proper recovery, of course) . It doesn’t get any simpler than that. However, few know the ‘mechanics’ behind the process. The key concept is muscle hypertrophy.
What is skeletal muscle hypertrophy ?
It is a process triggered by exposing your muscle tissue to outside mechanical stress which over time forces your body to build new muscle tissue to adapt to the stress. That’s why in order to build as much muscle mass as possible you need to understand this process thoroughly.
That’s the purpose of this article. We will go over the basic parts of this process and even though we may use some scientific terms to describe certain concepts, they will be explained along the way.
1. Skeletal muscle tissue is comprised of muscle fibers
When viewed through a cross-section muscle tissue is made up of lots of fibers packed together into tight bundles. Every muscle has two kinds of muscle fibers. The first kind is used for endurance activities, the second is for strength activities. Muscle size is directly related to the size of the fibers and when you stimulate fiber growth, you will start gaining muscle size too.
Slow-twitch muscle fibers type
The slow-twitch type of fibers isn’t particularly strong, but they are tremendously enduring. They are surrounded by blood vessels which enable the fibers constant oxygen supply and makes them very resistant to fatigue.
Fast-twitch muscle fibers type
The fast-twitch type is the opposite of the slow-twitch. They are very strong, but at the same time they get get tired very quickly. In short, slow-twitch fibers are used for low-intensity exercises done over a longer time period and fast-twitch fibers are used for intensive and short bursts of energy.
2. Training causes stress to muscle fibers
Training causes mechanical stress to the body and forces it to change the fiber structure and adapt to the stress, making them bigger, stronger and more enduring, which will make the load easier to handle. There are three ways to stimulate growth in your muscles:
Progressive overload and tension
What we mean by tension is the amount of time the muscles are used and by increasing the load and exercise duration in a gradual manner, we force muscle adaptation.
Training causes micro-tears in the muscle fibers, forcing the body to strengthen and repair the damaged fibers.
Muscle cell fatigue
When we push the muscle to the absolute limit, we also exhaust the fibers and thus cause the muscles to adapt.
3. Different stimulus types cause different muscle fibers growth
Lifting weights can stimulate growth via all three of the aforementioned methods, however, the body will react in a different way related to the type of exercise you will be doing.
Light(er) load, lots of repetitions.
This type of training is extremely popular with recreational lifters and bodybuilders and usually consists of lifting low weights (around half of one rep max) for 10-12 repetitions, sometimes more. This type of training doesn’t require a lot of strength, but it does require endurance and mainly uses the slow-twitch fibers, but neglects the fast-twitch type.
It exhausts the muscles and causes the muscle cells to tire much faster. This stimulus forces to body to grow more muscle mass in a process called sarcoplasmic hypertrophy, which increases muscle size by engorging the muscles with fluids rich with the energy required to improve performance.
Heavy load, few repetitions.
On the other spectrum, we have lifting heavier loads (70% and above of your one rep max), for up to 6-8 repetitions. This type of training demands high strength levels but doesn’t require much endurance, which forces to body to use the fast-twitch muscle fibers. This type of training causes damage to the muscle fibers, instead of inducing cell fatigue.
This results in a different body response, a process known as myofibrillar hypertrophy. This too increases muscle size but it does that by strengthening and enlarging the muscle fibers themselves.
4. You should decide what your goal is and train accordingly
Both types of training described above produce different muscle growth results. By using the first approach of high-rep, low weight exercising, you get an increase in muscle mass but it is not permanent.
Sarcoplasmic muscle hypertrophy is observed as ‘the pump’, which is just a temporary muscle size increase that usually goes away in a couple of days. Even though this type of exercising will make you look jacked, it will not have a big overall impact on long-term muscle growth.
A much more permanent growth is achieved by the second type of training that causes myofibrillar muscle hypertrophy. Instead of engorging the muscle tissue with fluids that can afterward be gone quickly, this type of training actually, makes muscle fibers bigger and stronger. When training with relatively heavy loads you can stimulate this type of muscle mass growth, and even though you may not be as pumped, you will build much bigger muscle mass growth in the long-term.
Think of it as filling a frame with concrete. The first type has more concrete, but a thinner outer frame, while the second type has less concrete, but very thick and strong frame.
5. Progressive overload makes your muscles grow
Muscle size increases only when it’s stimulated by training on a consistent basis and ever increasing load. For example, when you start pressing 40lbs overhead for the first time it will give enough growth stimulus to your muscle, so that when you try it again it will be easier.
However, if you keep using the same load over and over, the muscle will adapt and since you are not increasing the load, the body thinks there isn’t any reason to keep building new muscle tissue.
In order to force the body to build new muscle mass, you need to progressively overload the muscles used, mainly by gradually increasing the weight every workout. Every time you add weight, the body continually keeps adapting by building new muscle to handle the increased stress. Try to increase the weight every time you go to the gym by small increments thus ensuring that you challenge the muscles enough and make continuous muscle growth.
As we said, progression has to be slow, gradual and in small increments. Building muscle takes time, and the body won’t have the ability to adapt to the stress if it’s too fast, too soon. Always make sure you do the exercises with a good form, before trying to add weight, and always strive to increase the poundage as little as possible.
6. A sample muscle hypertrophy training regimen
If you want to build muscle in the most efficient manner, go for heavy weight, a small number of repetitions and always overload progressively. In this article, we present you a sample hypertrophy workout regimen which follows all the concepts described above and it is meant to trigger an optimal muscle growth rate. Always do your warm-up before starting each workout and strive to increase the load every two to three weeks.
Muscle Hypertrophy Workout 1
Bench Press, 3×6, Heavy load
Dumbbell Bench press, 3×12 reps with moderate weight
Overhead Press, 3×10, Moderate load
Dumbbell flyes, 3×12-15, Lighter weights
Bent-over Barbell Rows, 3×6, Heavy load
Pull downs, 3 x 12, Moderate weight
Tricep Cable Pushdowns, 4×10-15
Dumbbell Bicep Curls, 4×12
Muscle Hypertrophy Workout 2
Back Squats, 3×6, Heavy load
Leg extensions, 3 x 12 Lighter weights
Deadlift, 2×6, Heavy load
Leg Press, 4×10, Moderate load
Lying Leg Curl, 3×10, Lighter weights
Standing Calf Raises, 4×12, Moderate load
Crunches 3×20 reps
Muscle Hypertrophy Workout 3
Overhead Press, 3×6, Heavy load
Chin-Ups, 3×10, Moderate load
Seated Rows, 4×10, Moderate load
Close-Grip Bench Press, 4×12
Barbell Biceps Curls, 4×12