At the primary levels of fitness and exercise application the reduction of body fat and increased aerobic conditioning are mutually inclusive processes. Simply stated, initially, those exercise procedures which enhance aerobic (cardiovascular) conditioning also promote the reduction of body fat. The basic explanation for this correlation is uncomplicated. The primary fuel source sustaining aerobic exercise is fat. It is therefore apparent that repeated exposure to aerobic exercise will stimulate the utilization of fat as the basic fuel source. That utilization reduces the primary element of available exercise fuel which is stored body fat.
Since there is much confusion regarding the basic differences between the elements for cardiovascular conditioning versus body fat reduction, a simple explanation is in order. For the purpose of stimulating positive, health- related cardiovascular adaptations the basic exercise formula consists of 3 to 5 weekly sessions sustained at a level of 60% to 85% of maximal aerobic capacity for a duration of 15 to 30 minutes. The latitude expressed in this formula should not be interpreted as a discrepancy. It is simply an allowance for the variation in the experimental exercise designs which have demonstrated positive correlation’s with significantly improved cardiovascular function.
The exercise formula for body fat reduction may be varied from the basic cardiovascular design in the following manner: For the purpose of reducing body fat, the exercise sessions can be performed on a daily basis. The intensity can be sustained at levels less than the 60% minimal level suggested in the literature and the duration can be extended up to 60 minutes per session. Each of these alterations have been reliably documented to provide additional or at least coequal benefits when applied to exercise conducted for the purpose of body fat reduction.
Apparently, total fat utilization is generally associated with positive cardiovascular responses to exercise. However, each mechanism exhibits a specificity when fully understood. In practical terms, this diversity allows the seeker of cardiovascular enhancement the leniency of fewer exercise sessions albeit at a more rigorous level than the fat reducer. Conversely, the seeker of fat reduction has a lesser requirement for more intense (harder) levels of exercise performance but has an increased return for longer, more frequent sessions which is not available to the seeker of cardiovascular improvement.
It should be reinforced that at the novice and intermediate levels of fitness, a wide latitude for exercise prescription exists. However, as the gradient of either leanness or cardiovascular condition approaches higher levels the specific diversity between these two objectives becomes more prominent. Reliable scientific literature indicates that the cardiovascular benefits derived from five weekly exercise sessions slightly exceeds that of three weekly sessions. However, that increased benefit demonstrates the concept of diminishing return. In fact there is no evidence that seven weekly sessions provide substantially more cardiovascular benefit than the minimum requirement of three weekly sessions.
For the purpose of exercise induced body fat reduction increased levels of exercise exposure appear to provide increased benefits. However, in a recently conducted experiment with long term weight management subjects a certain "threshold" level of exercise was indicated. Simply stated, apparently a limit exists with regard to the rate of body fat reduction that can be accomplished. This limit affects the short term fat reduction response and appears to provide the body's protection against any severe or "shocking" fat loss. This protective mechanism does not concurrently limit total fat loss or the continuation of gradual fat loss for a prolonged period of time.
For those interested in the application of aerobic exercise for either improved cardiovascular benefit or the reduction of body fat it is important to understand the specific cause and effect relationships involved. Both objectives may be achieved concurrently during the initial phases of fitness but at the later stages specific exercise strategies must be applied.