The cardiovascular system, consisting of the heart and blood vessels, is responsible for transporting oxygen-rich blood to the muscles and removing waste products.

Endurance refers to the ability of the body to sustain a given level of physical activity over an extended period of time.

The anaerobic system, particularly the ATP-PC and glycolytic pathways, provides energy rapidly during the initial burst of high-intensity exercise.

Mitochondria are the primary energy-producing organelles in cells, generating ATP through oxidative phosphorylation during endurance exercise.

Glucagon is released during exercise to stimulate the breakdown of glycogen and release glucose into the bloodstream, maintaining blood sugar levels.

Adaptation refers to the physiological and biochemical changes that occur in the body in response to regular exercise, leading to improved endurance capacity.

Type I muscle fibers are characterized by their slow contraction speed, high endurance, and reliance on oxidative metabolism.

VO2 Max represents the highest rate of oxygen consumption the body can achieve during maximal exercise.

Hyperthermia, or excessive body heat, can impair endurance performance by causing physiological strain and reducing the body's ability to regulate temperature.

The lactate threshold is the exercise intensity at which blood lactate levels start to accumulate rapidly, indicating the transition from aerobic to anaerobic metabolism.

Carbohydrates are the primary source of energy for muscles during exercise and are crucial for restoring glycogen levels post-exercise.

Lactate clearance refers to the body's capacity to remove lactic acid from the bloodstream and convert it back to pyruvate or other metabolites.

Interval training involves repeated bouts of high-intensity exercise interspersed with rest or low-intensity periods, improving both aerobic and anaerobic capacity.

Thermoregulation refers to the body's physiological mechanisms for maintaining a stable core temperature despite changes in the external environment.

Hypoxia, or reduced oxygen availability, at high altitudes can impair endurance performance by limiting the body's ability to deliver oxygen to the muscles.