Specificity Principle (Specificity of Exercise Training or SAID)

Specificity has to do with the specific responses that occur as a result of training. In order for long-term physiological changes or adaptations to occur, a repeated, or chronic, stimuli must be applied to the body, along with progressive overload. This means for new levels of fitness to be achieved, an exercise (the stimulus) must be repeated often over a period of time.

Specificity Principle of Exercise Training

The specificity principle states that these metabolic or physiologic changes are specific to the muscular, cardiorespiratory, and neurologic responses that are required by the exercise activity. The patterns of muscle firing, and the cardiorespiratory responses are the two variables that have the most specific change. ¹Ehrman, Jonathan K., Paul M. Gordon, Paul S. Visich, and Steven J. Keteyian. Clinical Exercise Physiology. Champaign, IL: Human Kinetics, 2013.

The specificity principle is also known as SAID or Specific Adaptations to Imposed Demands.

Training specificity tells us that, in order to achieve the greatest gains in our ability to perform a chosen task, the majority of our training must be spent performing that task or tasks that are extremely similar to it. So, for a long distance runner to improve his performance, the majority of training should be spent running long distances. The cardiorespiratory responses (the transport and use of oxygen), and the specific neuronal firing pattern of the muscles, in long distance endurance running, are quite specific. In fact, a marathoner, for instance, would not want to spend very much of his time running a distance of 1600 meters, since marathon distances are much greater than this, while a 1600 meter runner, would find little benefit from training sprint distances.

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There is evidence of specificity in VO_2max between different types of endurance training, as well. This is exemplified by research on swimmers that demonstrated that swim training showed no improvement in VO_2max on treadmill running. ²McArdle, William D., Frank I. Katch, and Victor L. Katch. Exercise Physiology: Nutrition, Energy, and Human Performance. Baltimore, MD: Lippincott Williams & Wilkins, 2010. ³Magel, J. R., Et Al. “Specificity of Swim Training on Maximum Oxygen Uptake.” Journal of Applied Physiology 38.1 (1975): 151-55. American Physiological Society. Web. 28 Oct. 2013

The same specificity is true in strength training, and any other performance pursuit. Anaerobic exercise, which is what strength and power training is, produces specific adaptations to strength and power that are quite different from those of aerobic training (See: Difference Between Aerobic and Anaerobic Exercise) Only a very small benefit can be seen between the two types of training. However, as above, the adaptations to training are much more specific than these broad categories suggest and the specificity principle goes much deeper. Just how specific training can be is how most misunderstand specificity. For example, for muscles to adapt to become maximally strong, training intensities of at least 80% and up to 100% of 1RM must be used. See A Bit About Specificity and Transfer Of Training Effect for more on this subject.

There is some overlap between certain activities. This overlap and how the fitness gained from one activity can transfer to another is called transfer of training effect, and this is part of the basis for cross-training. However, the transfer of adaptations from any specific activity to another activity is minimal compared to the training effects of the activity itself. For this reason, we would expect to see some transfer, for instance between the fitness effects of long-distance biking and long distance running. However, since running requires much more load-bearing, and the muscle firing pattern is different, a dedicated bike rider should not expect to be able to compete with a marathoner, and vice versa. ⁴McArdle, William D., Frank I. Katch, and Victor L. Katch. Exercise Physiology: Nutrition, Energy, and Human Performance. Baltimore, MD: Lippincott Williams & Wilkins, 2010.

See also: Reactive Training: Why Training Be Feel Doesn’t Work