The keys to selecting the right kinds of exercises for developing and maintaining each of the basic components of fitness are found in these principles:
Specificity - pick the right kind of activities to affect each component. Strength training results in specific strength changes. Also, train for the specific activity you’re interested in. For example, optimal swimming performance is best achieved when the muscles involved in swimming are trained for the movements required. It does not necessarily follow that a good runner is a good swimmer.
Overload - work hard enough, at levels that are vigorous and long enough to overload your body above its resting level, to bring about improvement.
Regularity - you can’t hoard physical fitness. At least three balanced workouts a week are necessary to maintain a desirable level of fitness.
Progression - increase the intensity, frequency and/or duration of activity over periods of time in order to improve.
Some activities can be used to fulfill more than one of your basic exercise requirements. For example, in addition to increasing cardiorespiratory 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 cardiorespiratory workout and save time.
How to Measure Your Heart Rate
Heart rate is widely accepted as a good method for measuring intensity during running, swimming, cycling, and other aerobic activities. Exercise that doesn’t raise your heart rate to a certain level and keep it there for 20 minutes won’t contribute significantly to cardiovascular fitness.
The heart rate you should maintain is called your target heart rate. There are several ways of arriving at this figure. One of the simplest is: maximum heart rate (220 – age) x 70%. Thus, the target heart rate for a 40 year-old would be 126.
Some methods for figuring the target rate take individual differences into consideration. Here is one of them: