Muscular hypertrophy refers to an increase in muscle mass. This usually manifests as an increase in muscle size and strength.
Typically, muscle hypertrophy occurs as a result of strength training, which is why it is normally associated with weight lifting.
There are two types of muscle hypertrophy: myofibrillar and sarcoplasmic. Some people may adapt their training to target different types of muscle growth. For example, some people will train to prioritize either muscle size or muscle strength.
This article will discuss what hypertrophy is and how to train for muscle hypertrophy.
Muscular hypertrophy, or muscle growth, refers to an increase in muscle mass. There are two types of muscular hypertrophy: myofibrillar, which is an increase in myofibrils, and sarcoplasmic, which is an increase in muscle glycogen storage.
Skeletal muscles connect to the bones by tendons and are responsible for movement. Bundles of muscle fibers, known as myocytes, make up the skeletal muscles.
Each myocyte contains myofibrils that allow the muscles to contract. Myofibrillar hypertrophy refers to when the number of myofibrils increases. This causes muscles to increase in strength and density.
The muscles also contain sarcoplasmic fluid. This fluid is an energy resource that surrounds the myofibrils in the muscles. It contains adenosine triphosphate, glycogen, creatine phosphate, and water. During a workout, more fluid moves to the muscles to provide energy.
Sarcoplasmic hypertrophy refers to the increase in volume of this fluid. It can make muscles appear larger, but it does not increase strength.
Strength training can help people build muscle, both from myofibrillar and sarcoplasmic hypertrophy.
This involves training against resistance that gradually increases over time. The strain this places on muscles causes damage to muscle fibers, which the body repairs.
Repeatedly challenging the muscles in this way causes them to adapt by growing in size and strength. People can train to promote muscle growth by focusing on strength training, doing a variety of exercises, and getting good quality sleep.
However, some conditions can disrupt muscular hypertrophy. For example, myofibrillar myopathy is a type of muscular dystrophy that typically causes muscle weakness during mid-adulthood. The symptoms usually start in the hands and feet before moving to the center of the body.
Strength training is an important way of building muscle size and strength. The goal of strength training is to induce muscle hypertrophy from straining the muscles to cause damage.
Strength training typically includes performing movements against resistance, including:
- lifting weights
- using resistance bands
- performing bodyweight exercises, such as pushups
- using weight machines
Different types of strength training are suitable for different fitness goals, and people can choose to focus on specific muscle groups.
For example, bodybuilders who train for muscle size typically perform moderate intensity exercises with short rest intervals. On the other hand, powerlifters training for strength perform high intensity exercises with longer rests between sets.
Global recommendations for physical activity include strength training at least twice per week.
Some people may benefit from more regular training, but it is essential to get sufficient rest to allow the muscles to recover and grow.
One 2016 review found that training the major muscle groups twice per week is enough to build muscle. There was a lack of evidence to suggest that training three times per week would lead to greater improvements than training twice per week.
Resting between sets of exercise is also important for muscle recovery. A 2017 review suggests that rest intervals of more than 2 minutes are necessary to maximize strength gains in resistance trained individuals.
Building muscle will require consistent strength training over several weeks. Increasing the resistance gradually over time will help muscles grow.
There are no shortcuts for building muscle. It takes consistent training and following a healthful lifestyle for several weeks or months. However, there are some things a person can do to support the process.
Following a consistent routine that includes all the major muscle groups is essential for building muscle. Compound movements, such as squats, are effective for building muscle.
It is also necessary to progressively increase the resistance over time. Staying on the same weight for too long will not challenge the muscles and will prevent hypertrophy.
If possible, hiring a personal trainer is a good option for people starting out with strength training. A personal trainer can help someone develop personalized exercise routines and practice good form to prevent injuries.
Diet is another important consideration. People who want to build muscle should aim to eat a healthful diet rich in macronutrients.
Protein is an important part of the diet for building muscle. That said, the exact amount of protein necessary for muscle growth is still unclear. Research suggests that getting more than 1.62 grams of protein per kilogram of body weight per day is unlikely to produce additional benefits.
Myostatin-related muscular hypertrophy is a rare condition that causes high muscle mass. People with this condition have up to twice as much muscle mass. They typically also have low body fat.
A genetic defect in the MSTN gene causes this condition. It disrupts the production of myostatin, which usually controls muscle growth. By reducing myostatin, the condition causes uncontrolled muscle growth.
Myostatin-related muscular hypertrophy is unlikely to cause any serious medical conditions.
Muscular hypertrophy involves increasing muscle size, typically through strength training. Putting strain on the muscles through working out causes the body to repair them, resulting in an increase in muscle fibers.
Having more muscle fibers will lead to greater strength and muscle size. Strength training can involve a variety of exercises against some form of resistance. Increasing the resistance over time will lead to muscle hypertrophy.
Muscular hypertrophy can take time to produce noticeable changes in muscle size or strength. In addition to strength training, people should also incorporate healthful habits — such as eating a balanced diet and getting plenty of sleep — to optimize muscle gain and strength.