Hypertrophy: The golden word thrown around each and every gym almost as much as “anabolic window." The difference is obviously that hypertrophy is a real thing. When 99% of people use the term hypertrophy, they are using it synonymously with the word “pump.” To these people, when you perform high rep sets, and your muscles fill with blood (oxygen) the result is a very nice pum…. well…hang on, that’s too basic. The result is hypertrophy. Cue the “oohs” and “ahhs.” While this is true, it is only partially true. It also carries the implication that you cannot receive a “pump” from lower rep training. I’m willing to bet a vast majority of powerlifters, who consider running from high rep training as a form of cardio, would disagree. That’s neither here nor there. The reason that statement is only partially true is because there are actually two forms of hypertrophy, and they both work almost oppositely.
- Sarcoplasmic Hypertrophy. The sarcoplasm is the cytoplasm of the muscle cell, and contains large amounts of stored glycogen, ATP, creatine phosphate, and water. Going back to high school biology, the cytoplasm is essentially the most important part of a cell, as this is where all of the “important” functions/features of the cell take place (metabolic activity, giving a cell it’s shape, breaking down waste, etc.). So, sarcoplasmic hypertrophy, is hypertrophy that specifically deals with the muscle cell as a whole. What takes place during this form of hypertrophy is that the fluid within the muscle cell increases, thereby enlarging the overall muscle cell. How? Well, the fluid within the muscle cell accounts for approximately 30% of the muscle’s size. Now, it is starting to make sense. Yes, this is the result sought after by 100% of bodybuilders. To obtain this form of hypertrophy, one would typically focus on higher rep training (8-16+ reps) with shorter rest periods (approximately around one minute).
- Myofibrillar Hypertrophy. The myofibril is a unit within the muscle cell. The “muscle fiber “contains several myofabrils. The function of the myofibril is to perform muscle contractions. The purpose of myofibrillar hypertrophy is to increase the number of myofabrils within the muscle. As myofabrils increase, there is a greater ability to exert muscular strength. This type of hypertrophy does not focus on increasing the overall size of the muscle, but rather increase the ability of the muscle to perform certain tasks. This is why NFL players can exert more strength than some professional bodybuilders, yet the muscular size of the NFL player is significantly smaller. To obtain this form of hypertrophy, one would typically focus on heavier weight with lower reps (1-5). Because strength is the goal, and more weight is being lifted, myofibrillar training will mainly contain large compound lifts (squats, overhead press, bench press, deadlifts, rows) and will require longer rest periods (2+ minutes).
When it comes to training the muscle, you must ask yourself whether you are training to increase the size or training to exert more strength. While there is some carryover (i.e training for size will make you stronger and training for strength will make you bigger), choosing a set/rep ratio that is goal oriented is key!