The phrase "anaerobic system" refers to a type of energy production in your body that works without using oxygen. It helps provide quick bursts of energy for intense activities, like sprinting or lifting heavy things.
Is there a decrease in anaerobic system performance after a certain amount of time. (philmaffetone.com)
Lastly, for very short bursts of energy, such as a 10 - second sprint, muscles can rely on another type of anaerobic system: they use up energy - storing compounds, called phosphagens, in muscular tissues. (sciencemag.org)
HIIT sessions will condition both your aerobic and anaerobic systems at the same time. (flexmastergeneral.com)