Which physiological change can occur with cardio respiratory endurance training?

Increased stroke volume is a significant physiological change that occurs with cardiorespiratory endurance training. Stroke volume refers to the amount of blood ejected by the heart with each beat. Through consistent endurance training, such as running, cycling, or swimming, the heart becomes more efficient. This efficiency is achieved because the heart muscle strengthens, allowing it to pump a greater volume of blood per contraction.

As a result, a trained athlete can deliver more oxygenated blood to the muscles during exercise, which is critical for sustained physical activity. This adaptation enables athletes to perform at higher intensities for longer periods without excessive fatigue, which is crucial for endurance sports.

In contrast, decreased cardiac output, reduced heart rate response, and decreased oxygen uptake do not align with the expected benefits of enhanced cardiorespiratory fitness. Cardiac output may remain stable or even increase in trained individuals due to higher stroke volume, while heart rate response also typically improves as the body becomes more efficient in its use of oxygen. Oxygen uptake, or VO2 max, tends to increase in response to training, allowing for better overall performance.