What Causes Muscle Hypertrophy?

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muscle hypertrophy Peter Bowen

During strenuous physical activity, the muscles can be subjected to multiple stresses that cause muscle hypertrophy. One of these stresses is peripheral fatigue, which occurs when the muscles become unable to complete the exercise. The more peripheral fatigue a muscle endures, the more work it will have to do to grow. Also, the length of the tendons in a muscle is a contributing factor in the size and shape of that muscle. Shorter tendons result in bigger muscles, while longer tendons result in smaller muscles.


Mechanosensors cause muscle hypertrophies by activating signaling pathways in the sarcomere. These signaling pathways are thought to cause muscle hypertrophy by triggering different genes. These genes include CSRP3 (Cystin Receptor Protein), titin (Elastin), and GPR56.

The generation of mature muscle cells is essential for the repair of muscle tissue. This regeneration is promoted by physical exercise, which is a major intervention for muscle strength and endurance. However, some individuals do not respond to exercise, and the mechanisms responsible for this resistance are not yet understood. However, the cilia in skeletal muscle satellite cells are essential mechanical sensors for exercise-induced muscle hypertrophy. The discovery of cilia in these cells may allow for future interventions targeting this component.

Several experimental approaches have been used to identify which muscle genes cause muscle hypertrophy. In a previous study, SCs were eliminated by diphtheria toxin, and subsequent studies with synergist ablation showed that the absence of SCs did not cause muscle hypertrophy. Moreover, an SC-specific knockout of the muscle-specific gene myomaker inhibits SC fusion.

Protein synthesis

Muscle protein synthesis is an important metabolic process in muscle tissue. It is responsible for the changes in muscle mass that are observed after endurance or resistance training. MPS is measured as the rate at which amino acids are incorporated into bound skeletal muscle proteins. There are two types of muscle proteins: contractile myofibrillar proteins and energy-producing mitochondrial proteins.

Muscle protein synthesis is controlled by a balance between protein breakdown and synthesis. This balance determines the change in protein levels in myofibers. In response to exercise, protein synthesis increases, and the breakdown of protein decreases.

Protein breakdown

Muscle hypertrophy is a common process in which the body repairs damaged muscle fibers. This results in increased muscle mass. Several factors contribute to muscle hypertrophy, including a healthy diet and regular resistance training. These factors can influence muscle growth in different people. For example, the hormone testosterone and the amount of estrogen in your body can affect muscle growth.

During physical activity, a muscle’s cross-sectional area is increased, and it may experience an increased rate of protein breakdown. This is called in-series hypertrophy. The process involves synthesizing new muscle proteins by ribosomes inside the muscle cell. These ribosomes read a muscle cell’s genetic blueprint, coded by messenger RNA.


Although muscle hypertrophy can occur in various ways, clinical genetic testing is the best way to diagnose this condition. Generally, muscle hypertrophy can be treated with a specialized diet and regular weightlifting. To maximize muscle growth, eating a high-quality protein-rich diet is essential. Lean protein is ideal. Protein should be consumed within 30 minutes of a workout to maximize muscle growth.

Exercise causes muscles to hypertrophy by increasing the force of contraction in individual muscle fibers. This increases protein synthesis, which increases muscle size. Aim for maximum muscle hypertrophy by engaging as many muscle fibers as possible. A recent podcast from the NASM-CPT on the biomechanics of hypertrophy explains this process. Increasing blood flow to muscle groups helps promote the growth of muscle cells.

Cellular hydration

There is an unresolved question as to whether cellular hydration causes muscle hypertrophy or not. The process of water entry and exit from muscle cells is associated with the contractile cycle. It plays an important role in the conformational change of myosin and actin filaments from their union state to a free state, where contraction is generated.

Water plays several crucial roles in the body, including regulating body temperature and transporting molecules. In addition, aging is accompanied by progressive dehydration, which leads to impaired muscle function and strength. Dehydration also reduces intracellular protein structures. Dehydration also increases muscle wasting and reduces contractile capacity. Moreover, the amount of ICW in lean mass is independently associated with muscle strength and functional capacity.