Question

Why do we get tired on quick exercise?

Answer 1

During exercise the muscles work hard to lift a load. Whether it be resistance training or aerobic exercise, the muscles are under siege. The body’s neural response to this load is to recruit muscle fibers to complete the task, but muscle fibers become tired rather quickly. This is due to muscle tissue’s main source of energy, called adenosine triphosphate, or ATP. As the muscles use up this energy source, they become tired and fatigued. Hence we get tired faster on quick exercise.