Explain how each of the three principles of cardiovascular fitness can lead to injury if they are not adhered to properly..

A sample response follows: Overload can lead to injury if a person ignores his or her body's warning signs and continues applying stress to overworked muscles. Progression can easily lead to injury if an exercise program scales too quickly in difficulty. Specificity can contribute to injury if a person doesn't adhere to reasonable and attainable goals and attempts to do too much, too soon.