when a person is making cardiovascular gains through aerobic activity, they are increasing what to the lungs and heart?

Specifically, the following enhancements are often observed:

1. Cardiac Output: There is an increase in cardiac output, which is the volume of blood the heart pumps per minute. This is due to an increase in stroke volume (the amount of blood pumped with each heartbeat) and, to a lesser extent, resting heart rate may decrease.

2. Oxygen Uptake: The lungs become more effective at oxygenating the blood, which means that a larger amount of oxygen can be extracted from the air and transferred to the blood.

3. Capillarization: There is an increase in the number of capillaries (small blood vessels) in the muscular tissue, which allows more blood and therefore more oxygen and nutrients to reach muscle cells.

4. Heart Muscle Strength: Regular aerobic exercise strengthens the heart muscle, improving its ability to pump blood efficiently.

5. Lowered Resting Heart Rate: Because the heart becomes more efficient, it doesn't need to work as hard when you're at rest or during low-intensity activity, therefore the resting heart rate can decrease.

6. Improved Recovery Rate: The rate at which the heart rate returns to normal after exercise is faster because the cardiovascular system adapts to handle higher workloads more efficiently.

These cardiovascular gains contribute to better overall fitness, increase endurance, and often lead to a healthier life.