Our muscles can grow bigger in two different ways. Imagine your muscles are made up of tiny building blocks called fibers. When we do exercises that involve lifting heavy things, these fibers get stronger and increase in number. This is called myofibrillar hypertrophy. It helps us become stronger and more powerful!

The other way our muscles can grow is by filling them up with special stuff called sarcoplasm. This stuff helps our muscles have more energy and endurance. When we do exercises with lots of repetitions, like lifting lighter things many times, our muscles get bigger because of this sarcoplasm. It’s like filling up a balloon with air, making it bigger and able to last longer.

Sometimes, both of these ways can happen at the same time. It depends on the type of exercise we do and what we want to achieve. Some people want to be strong like weightlifters, while others want their muscles to be big and last longer, like bodybuilders.

So, remember, muscles can grow bigger by either adding more building blocks or filling them up with special stuff. It all depends on the kind of exercise we do.