How long does the anaerobic glycolytic system last during muscle contraction?

The anaerobic glycolytic system, also known as the lactate system, is primarily responsible for producing energy during high-intensity activities lasting from approximately 30 to 90 seconds. This system does not require oxygen and generates ATP through the breakdown of glucose or glycogen, producing lactate as a byproduct.

During muscle contractions that last around 30 to 40 seconds, the anaerobic glycolytic system provides sufficient energy to continue performing more intense physical activities after the phosphagen system (which lasts about 10 seconds) has been depleted. Consequently, the range of 30 to 40 seconds effectively characterizes the duration in which this energy system operates most efficiently before transitioning to aerobic metabolism for prolonged efforts.

This understanding is critical for physical therapists and assistants in designing appropriate exercise programs and rehabilitation protocols, ensuring that they target the appropriate energy systems based on the duration and intensity of activity.