To be effective, an exercise program must be
a.
uniquely tailored to every person
b.
maintained at a constant level of difficulty
c.
applied generally to whole-body fitness
d.
constantly increasing in difficulty

To be effective, an exercise program must be constantly increasing in difficulty. This will regularly increase the muscular fitness of the participant and enable him to increase bone strength and muscular fitness. Also, the increased strength and endurance produced by constantly increasing the intensity of an exercise program promote wellness and reduce disease risks.