Which of the following describes isometric muscle exercise?
1.Muscle size and strength will increase because the muscle fibers are making more
2.Muscle endurance increases because the circulation to the muscles is enhanced.
3.Muscle size increases because the muscle fibers produce more mitochondria.
4.Muscle flexibility is increased because the muscle continually shortens.
5.Muscles do not shorten during contraction so the muscles do not increase in size.