diaphram
the diaphragm is the muscle(s) that are most important muscle used in inspiration (inhalation)?
Diaphragm
Your heart
The diaphragm, it is the main muscle used for breathing.
In the human body, the host used muscle would be the tongue, or facial muscle muscles (provided you are not paralyzed). The most used organ would be the heart.
The myocardium, or heart, is the most used muscle in the body.
The heart
Quads; the quadriceps.
Hockey probably gains the most muscle. In hockey, leg, chest. back, shoulder, and all your arms are used.
cardiac muscle is only found in the heart so it is used constantly but it isn't the most common muscle found in the body, this would be skeletal muscle.
The heart, as it is a four-cambered muscle that continuously (we hope!) pumps blood round the body.