Progression
Overload
Specificity
Regularity
Increase the Frequency, Intensity and/or Time/duration and Type of activity over periods of time in order to improve. An easy way to remember this is FITT! Some activities can be used to fulfill more than one of your basic exercise requirements. For example, in addition to increasing cardiovascular endurance, running builds muscular endurance in the legs, and swimming develops the arm, shoulder and chest muscles. If you select the proper activities, it is possible to fit parts of your muscular endurance workout into your cardiovascular workout and save time.