General Adaptation Syndrome (GAS)

Hans Selye, a Hungarian biologist who worked around the middle of the twentieth century, outlined a model that underlies the training process. When you train, you introduce a stimulus, or “stress” to your body. This is followed by a “response” from the body which leads to a physiological “adaptation.” Selye called this stress-response-adaptation process the general adaptation syndrome (GAS).

The work you do during a training session breaks down the body, followed by a recovery phase during which the body rebuilds stronger than before. This is another way of describing the general adaptation syndrome. As a result of the process, you gain fitness, or the ability to perform faster and longer than before.

Many athletes take the ideas of the GAS and reason, “If training makes me stronger and faster, more training should make me even stronger and even faster.” This is true as long as you are adequately recovering in between those training sessions. You can run into trouble, however, if you are comparing your training load with other athletes and simply trying to match the volume and intensity of their training programs. Crucially, it is not the absolute training load that matters, but the training load that your body can handle.