Mass-Building Exercise

Muscles grow in response to specific stimulus. So, whether you refer to it as bodybuilding or pumping iron, all muscle-building exercise is a form of stimulus training.

On the most basic level, strength training with heavy weights increases the number of protein strands (microfibrils) and protein filaments that make up individual muscle fibers. So, while you cannot grow more muscle fibers, you can grow the muscle fibers themselves. When you lift weights frequently and properly, the fibers will grow enough for you to see and feel the difference. In other words, as long as you lift often and in the right way, your muscles will get bigger.

Muscle growth is a result of adaptation

When you stimulate your muscles by lifting weights, you force your muscles to adapt to the stimulus. This is called neural adaptation.

A good example is the "tight" feeling you experience when you first start lifting weights or after you increase the intensity of your training. Your muscle adapt to the new stimulus by remaining in a heightened state of readiness - therefore, they feel rigid. Similarly, you may experience rapid gains in strength because your body assigns more muscle fibers toward an exercise as it adapts to, or "learns", the movements involved. Each time you do the exercise, your body anticipates the movements and assigns more muscle fibers to the task.

This process continues each time you provide the body with adequate stimulus - and the easiest way to do that is by using heavier weights. Eventually, your body will begin adding protein filaments to your muscle fibers in an attempt to adapt to the heavier loads. The results is that your muscles will become larger and stronger.

Overcoming natural limits on muscle growth

While your body is quick to add new muscle fibers when you first begin stimulus training, you will find that the growth slows down over time. This is because your body is responding to millions of years of human evolution in a world of scarce food resources. Our bodies are naturally wired to maintain the minimum amount of muscle required for our daily tasks.

From your body's perspective, large muscles are wasteful and inefficient because they burn up too much fuel. This is why you need to give your body new stimuli, heavier loads to lift and more reps to push out. You must trick your body into believing you need bigger muscles to get through your day. Muscle-building supplements also can be a major factor in overcoming natural limits on muscle growth.