Oxygen is the lifeblood of the body. Oxygen is important to blood cells because it is necessary in making energy for our bodies. A body low on blood oxygenation functions at a much lower level. A healthy cardiovascular system delivers much-needed oxygen to the blood. Any activity that gets the heart beating faster contributes to an increased oxygen level. Running, skipping, walking, jumping rope, bouncing on a trampoline, or using an elliptical are examples of cardio-strengthening activities. Strengthening is not so much about what you do, as it is that you do something.

A strong church is built by developing strong cardiovascular systems. Fit churches need cardiovascular endurance to develop at a steady and sustained pace. It is cardiovascular endurance that provides the needed oxygen to produce energy in the church. Three functions that produce this energy for churches are outreach, effective evangelism, and community engagement. Each of these increases the cardiovascular levels of churches.