Hypertrophy: What it is and How to Build Muscle

Athletic man and woman with a dumbells.

There is no need to complicate your muscle building routine. You could spend hours online looking for a new workout, try dozens of different muscle building supplements, and waste a lot of money on placebos that don’t work. One way to keep weight gain simple is with hypertrophy. This complete guide tells you what it is and show you how to maximize your workout to build muscle.

What is Hypertrophy?

Hypertrophy is increasing muscle by increasing the size of its cells. Bodybuilders and athletes are interested in hypertrophy of skeletal muscle to build its size. Skeletal muscle is one of the three types of muscles found in the body [1].

In addition to skeletal muscle, the body has smooth muscle and cardiac muscle. Cardiac muscle is involuntary muscle that makes up the heart. The cardiac muscle is responsible for the heart beats (rhythmic contractions) that pump blood through your body. The third type of muscle found in the  body is smooth muscle. Smooth muscle is the muscle that makes up the vital organs. Smooth muscle is also involuntary muscle and it is found in the lining of the blood vessels the bladder, the stomach, and the intestines.

Skeletal muscle is the muscle attached to the tendons and bones in the body. Skeletal muscle is voluntary muscle and it is responsible for movement with connective tissues. Skeletal muscle relies on messages from the brain sent through the nervous system and blood vessels.

Types of Hypertrophy

There are two types of hypertrophy: sarcoplasmic and myofibrillar [2].

  • Sarcoplasmic hypertrophySarco refers to the flesh and plasmic refers to plasma. Sarcoplasm is the plasma in the cells of muscles. Sarcoplasm is mainly composed of collagen, glycogen, protein, and water. To cut to the chase, sarcoplasm is simply increasing size by increasing the fluids in the muscle. Some believe that a weight training regimen that increases the fluid around the cells makes them dense. The goal of sarcoplasmic hypertrophy is an aesthetic one – bigger, solid muscles. Sarcoplasmic hypertrophy is not to be confused with myofibrillar hypertrophy that increases size and strength. There is no evidence to support sarcoplasmic hypertrophy theories, but several blogs talk about it as if it really works. It is suspected that you can increase sarcoplasmic volume of a muscle by eating nutrient-rich carbs, loading creatine, and damaging the muscle with overloading the muscle and and encouraging resistance.
  • Myofibrillar hypertrophy – Myo refers to muscle and fibril refers to the structure of the cell. This is muscle growth achieved through increasing the myofibrils in the muscle fibers. Myofibrils are long fibre that are made up of both thick and thin myofilaments. Within the filaments are myosin, actin, troponin, and tropomyosin. The myosin and actin work together to contract the muscle.

Types of Muscle Fibres of Skeletal Muscle

To understand hypertrophy better, you need to get to know the types of muscle fibers of skeletal muscle. There are three types of skeletal muscle fibers [3]

Type I: Slow twitch fibres [3]

Slow twitch fibres contract slowly and can do so repeatedly for long periods of time.

Slow twitch fibres are also called “red fibres” because of the increased blood supply to them. Slow twitch fibres have myoglobin, oxygen and high levels of mitochondria. The muscles are resistant to fatigue and produce large levels of ATP (adenosine triphosphate through aerobic activity. When you do low-impact activities such as walking and biking, you are likely using Type I fibres.

The contraction speed is between 90 and 140 milliseconds. The small neuron means the fibres keep fatigue at bay because the nerve impulses don’t operate as quickly. The force for Type I muscle fibers is low, but they are sustainable over long periods of time.

Type IIa: Fast twitch fibres [3]

Type IIa, or fast twitch fibres, are fibres that are made for speed, weight training, and endurance. These fibres are called “white fibres” because they don’t need as much oxygenated blood. Fast twitch fibres can use both anaerobic (no oxygen) and aerobic (oxygen) sources for energy, Because of the limited blood flow, Type IIa fibres fatigue quicker than “red fibres” or slow twitch fibres.

Fast twitch fibres have a rapid speed of contraction. The contraction speed is between 50 and 100 milliseconds. The motor neuron is large, allowing the nerve impulses to move quicker. The resistance to fatigue is moderate. They produce high force in short, minimal reps of high intensity exercises.

Type IIb: Fast twitch fibres [3]

The second type of fast twitch fibres is Type IIb fibres. These fibers are also “white fibers,” but they are different that Type IIa fibres. Type IIb fibres use only anaerobic energy sources, which means energy comes from non-oxygenated energy sources. Fast twitch Type IIb fibres are for strength, heavy lifting, and other power activities. Type IIb fibres contract very rapidly, but they also fatigue quicker than Type I and Type IIa fibres because they use no oxygen at all.

The contraction speed is rapid at 40 to 90 milliseconds. The large motor neurons permit the nerve impulses to work quickly. Combine those features with no oxygen and the resistance to fatigue is very low. Type IIb fibres produce high force for very short periods of time when doing maximal intensity exercises.

Hypertrophy Training for Bulk

Now that you know the different types of muscle fibers in skeletal muscle, it’s time to get down to how they work and what effect hypertrophy has on muscle. Bodybuilders, athletes, and gym-goers use exercise to challenge their muscles so the muscle cells grow for more surface area. How does that work? The two important features of hypertrophy are high intensity workouts and resistance training [4]. The resistance training is the most important part because it increases endurance and strength overtime.

The Process of Muscle Growth with Hypertrophy

Anaerobic resistance training is the best for promoting muscle growth [5]. The force muscle be overloaded over a period of time and at varying stress levels. The process allows the muscle to adapt to the load. To increase strength and size, the muscle has to be challenged so it adapts.

There are three processes that influence growth: satellite cell activation, inflammation, and growth factors of hormones and cytokines (Hernandez and Kravitz).

1.Satellite cell activation

Satellite cells are also referred to as differentiated cells. They are quiescent mononucleated myogenic cells, which means they are inactive or dormant cells with one nucleus that originate from muscle tissue instead of nerves. The role of satellite cells in hypertrophy is promoting cell growth, but they must be activated in order to do so. These cells are inactive, but trauma and minor injury from strength training activates the satellite cells. Each muscle fiber has levels of satellite cells that affect growth. Type I muscle fibers have the greatest number of satellite cells. Type I muscle fibers have as many as 6 times more satellite cells than the Type II fibers because they receive more oxygen and blood.

2. Inflammation

Following trauma or injury to the muscle, inflammation occurs. Inflammation is the body’s immune response to the injury to repair the damaged the area. Inflammation includes a process of cytokine secretion to trigger the arrival of healthier cells, lymphocytes,monocytes, and neutrophils that help repair the injured area of the muscle damaged during weight training.

3. Hormone and cytokines growth factors

Hormones and cytokines are secreted to the skeletal muscle to encourage the process of hypertrophy. Hormones involved in the process are testosterone, cortisol, and growth hormone. To encourage hypertrophy, many athletes improve hypertrophy by adding synthetic versions of these hormones or peptides into their daily regimens.

Training for Maximum Hypertrophy

When doing any kind of weight training, what you must be aware of is the dreaded plateau. The workout plateau is inevitable if you stop only at the point when muscles adapt. Muscles aren’t very different from us. We become bored and don’t grow when doing the same things over and over. Your muscles do the same. Your training routine MUST advance.

Types of Exercises that Build Muscle

The exercises that build muscle are compound, multi-joint exercises. They use and stimulate more muscle fibers for growth. The best ones are the exercises that use all or most of the muscles in the body.

When designing a workout for hypertrophy, remember three things: metabolic stress, muscle damage, and progressive tension overload. Metabolic stress is the is the process of working the muscles to their limits with repetitive actions. The stress causes muscular failure. Progressive tension overload is the process of increasing the load on the muscle by increasing weight overtime. Muscle damage is not as traumatic as it sounds. Muscle damage is what most people refer to as “microtears.” Microtears in the fiber are essential for growth.

The following exercises are examples of exercises that achieve hypertrophy for muscle growth [6].

Hypertrophy Exercises for Chest

When you do chest exercises, do 10 sets of chest exercises every other day. When you do chest exercises, never push the muscle to failure. Always stop one rep short of muscle failure.

  • Bench Press/Barbell Bench Press

When you do the bench press, lie flat on your back on the bench. Hold the barbell with a medium-width grip. Your arms should be at a 90-degree angle. When you lift the bar off the rack, lift it straight up and lock your arms. This is your starting position. Take a breath as you slowly lower the barbell down to your chest. Pause only for a moment before breathing out as you slowly lift the bar back up to the starting position.

  • Cable Crossovers/Flyes

The cable crossover/flyes can wait until the end of your workout. Make sure you never lock your arms straight. Keep the elbows bent slightly and locked. Stand in a starting position, pulling your hands in front of your body and taking a step forward. Select your resistance. Be careful not to add too much weight. Bend your waist slightly. Breathe out as you extend your arms out to your sides until you feel the stretch in your chest. Take a breath in as you slowly return your arms to the starting position.

  • Incline/Decline Bench

Get creative with your bench positions. Don’t limit yourself to the positions you have been comfortable with for so long. When you work on the incline bench, lower the bar to your clavicle instead of lowering the bar to the middle of the chest. When you work on the incline bench, reduce the weight and put most of your effort into the isometric pause of the movement. The isometric pause is a contraction that occurs when you are fully stretched but when the bar isn’t touching the chest. Hold the pause for 3 to 4 seconds.

Hypertrophy Exercises for Legs/Glutes

Hypertrophy exercises are great for the legs. They give the legs visible bulk, superior strength, and muscle training. When you are doing hypertrophy exercises for the legs, live by one rule: Keep it Simple! Here are the three exercises for legs that give you more mass and strength.

  • Stiff Leg Deadlift

To do the stiff leg, or stiff-legged, barbell deadlift, you may need a pair of wrist wraps for the amount of weight you will be lifting. Use the overhand grip to grab the barbell on the ground in front of you. Protect your back with this exercise by keeping your torso straight and your knees slightly bent. This is your starting position. As you perform the exercise, NEVER bend at the back. Bend at the hips. This is your starting position. Keep the knees still and you lower the barbell to the ground. The bar should be right above the top of your feet, not in front of your feet. You will feel this is the hamstrings. As you return to the starting position, keep your torso straight as you bend back up at your hips.

  • Leg Curls

There are two different types of leg curls: lying leg curls and seated leg curls. To do a lying leg curls, make sure you adjust the machine to your height before you get started. The lever should sit on the back of your legs, not on the Achilles or heels. Just below the calves is ideal. This is your starting position. With your stomach flat on the bench and your toes straight down, exhale as you bend the lever up to your glutes. Gently lower your legs back down to the starting position. To change up the intensity of the exercise, adjust your foot position.

  • Squats

There are two types of squats: one for powerlifting and one for bodybuilding. If you want power and physique, stick to the squat for bodybuilders. Powerlifters are concerned with fewer reps with as much weight as possible. Bodybuilders need the reps for strength and look. To do a squat for bodybuilding, stand with the barbell resting on the traps. Face forward and keep you back straight. Never lift your chin drop. Flex the knees as you sit back into the squat. The knees should go forward as your weight shifts to the front of your heels. When you feel the upper legs touch the back legs, slowly straighten the knees as you return to the starting position.

Hypertrophy Exercises for Back

Don’t avoid the back. You need the back to be strong for the rest of the body to work properly and get stronger. Remember when you do work that back that you should never slouch or limit your range of motion. Always try different grips and move across multiple planes for the best workout. Here are a few killer back exercises.

  • Deadlift

Instead of keeping the legs straight, you need to put more of a bend in the knees. Depending on your level of training, you might start out with the trap bar to help keep you center or the sumo to help you with mobility. The conventional deadlift is still the star though. A conventional deadlift will cause pain in your spine and knees if you have never done them before or if your form is compromised.

  • Rows

The rows are great for the chest and the back. The bent over barbell row and seated cable row can be added to your workout during the week. To do a bent over barbell row, use the pronated grip to hold the barbell. Bend you knees as you bend slightly at the waist and keep your torso straight. Your arms should be straight and the barbell at your knees. This is your starting position. To perform the exercise, breathe out as you lift the bar to your chest. Don’t straighten your back as you raise the bar. Inhale when you lower the bar back to the starting position.

To do the seated cable row, sit on the machine with your torso straight and a cable in each hand. Your knees should be slightly bent. When your arms are extended, this is your starting position. Exhale as you bring your hands back, arching your back slightly. Pinch your shoulder blades together as you perform the exercise. Slowly inhale as you return to the starting position.

  • Chin-Up

The chin-up is one of the greatest tests of strength. Again, don’t be afraid to change up the grip. With your palms facing you, grab the bar, extend your arms and keep your back straight. This is your starting position. For added intensity, add weights to your ankles. Keep your torso straight and use pull your body to the bar.

Never lose sight of the goal when training: hypertrophy. Progress, add more weight, and do fewer reps for maximum definition. If your muscles need a boost to maintain stamina and endurance to support your workout, try the Fulcrum and WheyXX combo to help your muscles. One more thing: never forget rest days. One of the most important features of hypertrophy is rest. Your muscles need to rebuild, and rest is the only way to get that done. 

What is your best hypertrophy trick to build muscle?


  1. The development of skeletal muscle hypertrophy through resistance training: the role of muscle damage and muscle protein synthesis.
    Damas F1,2, Libardi CA3, Ugrinowitsch C4. Eur J Appl Physiol. 2018 Mar;118(3):485-500. doi: 10.1007/s00421-017-3792-9. Epub 2017 Dec 27.
  2. Different modes of hypertrophy in skeletal muscle fibers
    Angelika C. Paul and Nadia Rosenthal J Cell Biol. 2002 Feb 18; 156(4): 751–760.
    doi: [10.1083/jcb.200105147]
  3. Skeletal Muscle Fiber Type: Influence on Contractile and Metabolic Properties
    Juleen R Zierathcorresponding author and John A Hawley PLoS Biol. 2004 Oct; 2(10): e348. Published online 2004 Oct 12. doi: [10.1371/journal.pbio.0020348]
  4. Skeletal Muscle Hypertrophy after Aerobic Exercise Training
    Adam R. Konopka1 and Matthew P. Harber2 Exerc Sport Sci Rev. Author manuscript; available in PMC 2015 Aug 4. Published in final edited form as: Exerc Sport Sci Rev. 2014 Apr; 42(2): 53–61. doi: [10.1249/JES.0000000000000007]
  5. Effects of Aerobic And/Or Resistance Training on Body Mass and Fat Mass in Overweight or Obese Adults
    Leslie H. Willis,corresponding author1 Cris A. Slentz,1 Lori A. Bateman,1 A. Tamlyn Shields,5 Lucy W. Piner,1 Connie W. Bales,3,4 Joseph A. Houmard,5 and William E. Kraus2 J Appl Physiol (1985). 2012 Dec 15; 113(12): 1831–1837. Published online 2012 Sep 27. doi: [10.1152/japplphysiol.01370.2011]
  6. Increasing Lean Mass and Strength: A Comparison of High Frequency Strength Training to Lower Frequency Strength Training
    MICHAEL H. THOMAS† and STEVE P. BURNS, PhD‡ Int J Exerc Sci. 2016; 9(2): 159–167. Published online 2016 Apr 1
Leave a Reply

Your email address will not be published.