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. Full definition
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)