Exercise stimulates the body’s many systems to respond accordingly. When a person consistently participates in an exercise program the body will adapt in direct response. If the execise program is appropriate, the body will improve the target systems. If the program is not appropriate, the systems will be affected in a negative manner.
This is similar to the body’s reaction to medications. The right medication used appropriately will yield the desired results. Too little or too much medication will not produce the desired affect and may cause more harm.