What Is Muscular Hypertrophy and How Is It Achieved?
There are two types of muscular hypertrophy, Myofibrillar and Sarcoplasmic.
Myofibrillar Hypertrophy refers to an increase in myofibril size. This happens when you stimulate your muscles by lifting heavy weights, which causes little tears to the individual muscle fibers. Since your body treats this as an injury, it overcompensates by sealing and strengthening them with more proteins which also leads to a small increase in muscle size. This happens because the muscles need to increase maximum strength and speed with less of a need for energy storage and endurance. The best way to achieve this is to perform lower reps approximately (1-5) of heavy weight approximately (80%+) of 1 rep max with rest times between 3-5 minutes.
Sarcoplasmic Hypertrophy also known as "the pump" refers to an increase in the volume of sarcoplasmic fluid in the muscle cell without an increase in muscle strength. Sarcoplasmic fluid contains ATP, glycogen, creatine phosphate and water. Sarcoplasmic hypertrophy occurs when the amount of sarcoplasmic fluid in your muscle cells increase. This happens because the muscles need to last longer with less of a need for maximum strength and speed and more needed for energy storage and endurance. This would add to muscle bulk, but not necessarily grow fibers, resulting in less functional mass and a reduction in relative strength because it would be adding less useful bodyweight. The best way to achieve this is to perform higher reps approximately (8-15) of moderate weight approximately (65%-75%) of 1 rep max with minimal rest times between (45-90) seconds. According to MYFITNESS essentially sarcoplasmic hypertrophy is a kind of artificial muscle growth. You’re training the muscle for no other reason than to increase it’s size visually by increasing the amount of fluid it can hold, but you’re not increasing the density of the muscles fibres
This is why powerlifters are much smaller than bodybuilders but can easily out-perform when lifting heavy weights.
How and When is Muscle Built?
When stress is placed on our muscles the muscle fibers tear. Since our bodies treat this like an injury, the injured cells release molecules called cytokines. Cytokines activate the immune system to repair the injury. The greater damage to the muscle tissue the more your body will need to repair itself. This cycle is what makes our muscles bigger and stronger. In order for this process to continue occurring our cells need to be exposed to greater loads (heavier weights) than they are used to. Exposing the muscle to great amounts of tension while the muscle is lengthening (also known as eccentric contraction) is most effective for maximizing muscle growth. I like to achieve this by performing slow eccentric contractions. Nutrition also plays a huge role in maximizing muscle growth. Optimal protein intake is essential because protein preserves muscle and provides the building blocks (amino acids) for new tissue. Hormones including Insulin, Growth Factor and Testosterone help put the body in a state where the tissue is repaired and grown. Make sure to get your sleep because this recovery process mainly occurs when we are sleeping. Our bodies adapt to whatever demand we place on them so if we consistently lift weights, eat correctly and rest we will see increases in muscle size and strength.