What type of exercise primarily targets anaerobic energy systems?

Weight lifting primarily targets anaerobic energy systems due to the nature of the activity, which involves short bursts of high-intensity effort. Anaerobic energy systems are utilized when the body requires immediate energy for activities that are intense and of relatively short duration, typically lasting from a few seconds up to around two minutes. This includes exercises that require strength, power, and explosiveness.

During weight lifting, the body relies on stored energy sources such as ATP (adenosine triphosphate) and creatine phosphate to quickly supply energy without the need for oxygen. This is in contrast to aerobic exercises, like marathon running, which depend on oxygen and fuel sources such as carbohydrates and fats for sustained energy during prolonged activities.

The other activities mentioned do not primarily utilize anaerobic energy systems. Marathon running is predominantly an aerobic activity, focusing on endurance over a long duration. Yoga and stretching emphasize flexibility and stability rather than high-intensity energy output, falling more into the category of low-intensity anaerobic tasks. Similarly, walking at a steady pace relies primarily on aerobic metabolism, as it allows for a steady supply of oxygen to meet the energy demands over a longer period.