Have you ever wondered why the guy in your gym who looks significantly smaller than you is able to put up more weight on the bench? It may be due to the difference in your training regimens. It is possible to gain a lot of size in your muscles without gaining a lot of strength. Conversely, it is also possible to greatly increase your strength without building too much muscle mass. When you lift weights, there are essentially two main types of muscle hypertrophy. The first type is known as sarcoplasmic hypertrophy. People who engage their muscles in sarcoplasmic hypertrophy end up adding much more size to their muscles, and proportionately less strength (although you can increase both at the same time, it is practically impossible to increase both at optimal levels.) You create sarcoplasmic hypertrophy in your muscles by activating your "slow-twitch" muscle fibers. This entails lifting weights for roughly six to twelve repetitions per set.
The second type of muscle hypertrophy is known as myofibrillar hypertrophy. When engaging your muscles in myofibrillar hypertrophy, you end up stimulating your central nervous system too a much greater level than you do when engaging in sarcoplasmic hypertrophy. This in turn builds more explosive strength, meaning that you will be able to lift a greater amount of weight. When initiating myofibrillar hypertrophy, you are still building muscle; however, the muscle you build is much more dense and compact than it is for sarcoplasmic hypertrophy, which is why you will not necessarily look as big. People who want to create myofibrillar hypertrophy should use heavy weights for one to five reps per set, which will activate your "fast-twitch" muscle fibers.
These a bare bones of sarcoplasmic and myofibrillar hypertrophy. I hope you enjoyed the card and found it useful!