Documented experiences of the second wind go back a minimum of 100 years, when it was taken to be a generally held fact of exercise. Regardless of whether or not the affected person experiences signs of muscle ache, muscle fatigue, or cramping, the phenomenon of second wind having been achieved is demonstrable by the signal of an elevated heart rate dropping while maintaining the identical speed on the treadmill. Inactive patients skilled second wind, demonstrated through relief of typical signs and the signal of an elevated heart charge dropping, while performing low-average aerobic exercise (walking or brisk walking). For osclass-classifieds.a2hosted.com the often energetic patients, en.encyclopedia.kz it took more strenuous exercise (very brisk walking/jogging or bicycling) for them to experience each the standard signs and relief thereof, along with the sign of an increased coronary heart fee dropping, demonstrating second wind. As such, these with muscle glycogenoses do not must do extended exercise to experience "hitting the wall". In experienced athletes, "hitting the wall" is conventionally believed to be due to the physique's glycogen stores being depleted, with "second wind" occurring when fatty acids become the predominant supply of vitality.

The delay between "hitting the wall" and "second wind" occurring, has to do with the gradual speed at which fatty acids sufficiently produce ATP (vitality)