Effects of Strength Training : 2 - The lungs :

1 - The muscles

2 - The lungs

Your body may need up to 15 times more oxygen when you exercise, so you start breathing faster and harder. Your breathing rate increases until the muscles around the lungs simply can't move faster.

This maximum oxygen utilization capacity is called VO2 max. The higher a person's VO2 max, the more fit the person is.
3 - The diaphragm