The strength of endurance of a muscle depends on lots of things. One main thing that it depends on is a healthy diet. What you eat and drink has certain chemicals that are healthy for you that your body consumes to help strengthen your muscle and build stamina whereas if you put something bad in your body it will evidently weaken your muscles and stamina.
Hope that helps!
Slowly extending stretches until the muscle hurts
Gradually increasing the challenge level of stretches
Quickly swinging the arms back and forth for more stretch
<span>Intensely holding stretches for five to 10 seconds</span>
The layer that encloses and protects the heart is
Pericardium
