Which of the following can increase both heart and lung fitness?

A) an external locus of control
B) elevated cortisol levels
C) biofeedback
D) aerobic exercise

Aerobic Exercise

Physical exercise that improves the efficiency of the body's cardiovascular system in absorbing and transporting oxygen.

Lung Fitness

The efficiency and capacity of the lungs to take in oxygen and expel carbon dioxide, important for overall respiratory health.

Cortisol Levels

The concentration of cortisol, a stress hormone, in the bloodstream, indicative of stress response and adrenal function.