They get tired like all things. Also ligaments a tendons start loosing up.
As you age, your skeletal muscles tend to decrease in size. However, studies have shown that if an aging individual continues to weight train, the amount of muscle loss is minimal
The nervous system tells the muscular system what to do.
Aging effect in electronics may affect the electronic instrument and control system of nuclear plants.
You might get slower reactions.
you get small balls when you use them :)
muscular and skeletal
The Muscular-Skeletal System.
Some signs that the cardiovascular system is aging are increased stiffness of the aorta, reduction in the cardiac muscle fiber size, progressive loss of cardiac muscular strength, reduced cardiac output, a decline in maximum heart rate, and an increase in systolic blood pressure.
The nervous system.
Depends what type of training you are referring to. Resistance training (weightlifting) with proper diet/nutrition will lead to increased muscular size, definition and strength.
the muscular and cardiovascular system.
the main organ of the muscular system is the muscles
Lack of physical activity