Aerobic Exercise Part 5
As I explained last month, the process of prescribing aerobic exercise to improve cardiovascular conditioning begins with health screening and cardiorespiratory assessment. Once these evaluations have been completed, an aerobic training program that is both safe and effective can be formulated. All exercise prescriptions should be based upon the principles of specificity and overload: For aerobic exercise, these tenets are satisfied by manipulating program components that include the mode, frequency, duration and intensity of exercise. These variables are assigned according to the requirements of the perspective exerciser with consideration given to age, gender, physical fitness/health status, prior exercise history and long-term objectives. Prescribing exercise also requires accounting for the concepts of progression and reversibility because the process must be ongoing so that changes that occur as the program progresses are accounted for in an appropriate manner.
To satisfy the principle of specificity, the mode(s) selected to train the cardiovascular system should overload the energetic system that relies predominantly on aerobic energy transfer. Generally speaking, aerobic (endurance) exercise includes all activities that require rhythmic contractions of a significant portion of the body’s larger muscle groups at a sustainable percentage of the involved musculatures’ maximal capacity to contract. Basic activities that fit this description include walking, jogging, running, cycling, rowing, swimming and cross-country skiing. These are complemented by many alternative forms of aerobic exercise that are typically done in the health club setting including treadmill walking/jogging/running, stationary leg cycling, arm cranking, stair stepping, elliptical stepping, aerobic dance and spinning. Factors that should be considered when determining an appropriate mode include the preference of the exerciser, geographic location (climate, urban/rural, topography), equipment availability (public health club proximity, private home gym feasibility), economic concerns and any orthopedic limitations that might be present.
Prescribing an appropriate endurance training mode also requires understanding which options are not appropriate for a specific exerciser. For example, certain aerobic activities require skilful execution that precludes their use for establishing a cardiovascular overload for unskilled subjects. An example is cross-country skiing (either outdoors or on an exercise apparatus designed to simulate the movement), which involves performance that is difficult to master. If execution presents a limitation that does not allow an exerciser to work hard enough or for a long enough continuous period (for example, if you can’t maintain a challenging pace during cross-country skiing because you cannot sufficiently keep your balance), it will be impossible to overload cardiovascular function with the maneuver, at least given the current level of proficiency. In such a case, sessions designed to improve performance can be incorporated into the training regimen, but these should be done in conjunction with (as opposed to in place of) those that effectively overload cardiovascular function until the novel movement is mastered and can be used for that purpose.
In addition to activities that mandate a significant level of technique mastery, there are also some aerobic exercises that require a minimum level of aerobic conditioning in order to be appropriate for cardiovascular training. For example, jogging is (in my opinion) the foremost aerobic training option, but it is inappropriate for many exercisers simply because it cannot be done at an extremely low work rate. Consequently, even individuals who express a desire to jog and have no orthopedic limitations that preclude its use as an aerobic training modality won’t be able to do so to train their cardiovascular system until they develop sufficient aerobic capacity to sustain the requisite pace. For these exercisers, fast-paced walking might provide an adequate stimulus overload upon initiation of the program and once aerobic capacity improves consequent to that type of training, sessions that involve walk/jog intervals can be done to bridge the gap between continuous full sessions of walking and jogging.
An appropriate aerobic exercise mode is only a useful tool if it is sufficiently palatable for the individual who will be asked to repeatedly perform the activity for many years to come. Consequently, even if jogging is best, a prospective exerciser that despises this form of aerobic exercise is probably not a good candidate for a jogging program. However, it is also important to realize that all challenging endurance exercise is somewhat unpleasant; therefore, there is some credence to the old no-pain-no-gain mantra. Unfortunately, in recent years, there has been a trend for exercise professionals to refute this and, specifically, suggest that an exercise alternative that the exerciser finds enjoyable must be chosen to promote long-term adherence. This is good advice so long as the principles of specificity and overload are respected. For example, an exerciser might enjoy an intense session of stretching followed by a relaxing leisurely walk, but neither form of exercise provides the required overload to make the cardiovascular system stand up and take notice. On the bright side, if you accept the realization that there is no choice but to devote a small fraction of time each week to an activity that may not qualify as fun and games, aerobic “cross-training” (utilizing different aerobic exercises either during the same exercise session or on different days) can be useful for helping you cope. Cross training is also beneficial because it reduces the likelihood of overuse injuries that result from the exact same physical stress being repeatedly applied.
This article was originally published in New Living Magazine, which can be accessed on-line at www.newliving.com.
