As people attain a level of fitness that meets their needs and further improvement is not desired, the program switches from developing fitness to maintaining it. At this point the principles of overload and progression may be set aside, but both are necessary for the improvement phase of fitness. Overload involves subjecting the body to unaccustomed stress. Challenging the body to periodically accept a slightly increased level of work forces it to adapt by attaining a higher level of fitness. When to impose each new challenge involves the principle of progression. The workload is increased only when the exerciser is ready to accept a new challenge. For aerobic exercise, target heart rate and/or perceived exertion may be used to establish criteria for scheduling the progression of exercise. For example, if you jog, swim, or cycle a certain distance, the exercise heart rate will decrease over time as your body adapts to training. When the exercise heart rate drops to a predetermined level, you should adjust the pace and/or distance to return to the original target zone.
The principle of specificity of training suggests that the body adapts according to the specific type of stress placed on it. The muscles involved in any activity are the ones that adapt, and they do so in the specific way in which they are used. For example, jogging prepares you for jogging but is poor preparation for cycling. Cycling does not prepare you for swimming. Although all these activities stress the cardiorespiratory system, they are sufficiently different that there is little fitness carryover among them.
The principle of specificity is particularly important for competitive athletes. Competitors attempt to maximize the returns from their training effort; therefore runners must train by running, swimmers must swim, and cyclists must cycle. The focus is on maximal improvement in one activity so that the body is trained in a specific manner. This locks athletes into regimented training programs, but people who exercise for health reasons are not under such constraints. They can vary activities and prevent the boredom of participating in the same activity week after week. Cycling, jogging, swimming, racquetball, cross country skiing, and weight training may be used in any combination or order for the development of physical fitness. This is the essence of cross training. Not only does cross training relieve boredom, it may reduce the incidence of injury because the same muscles are not being stressed in the same way during every workout.
Cross training has many advantages and is an excellent technique for attaining the health benefits of exercise. Variety, the major attraction of cross training, can also be a disadvantage. By participating in many different activities, you seldom become proficient in anyone. However, if the objective is health enhancement, proficiency is incidental.
Identifying goals provides some direction for the activities selected and the way the principles of exercise are to be manipulated to increase the probability of success. Only one or two major goals should be selected, and these should be as specific as possible so that an effective exercise program may be devised. Activities, objectives, and principles must match.
When you have identified the objectives and know what you wish to achieve from the exercise program, the means for sustaining the program must be identified next. The resolve to exercise is shakiest during the early stages of the program, usually because people push untrained bodies beyond their limits. This results in sore muscles, stiffness, and possible injury. The drop out rate is highest in the beginning of any exercise program. The irony is that the greatest return for the effort is attained during this phase.
Tags:cardiorespiratory system, exertion, improvement phase, locks, principle of specificity, target zone workload