What is a possible effect of regular physical exercise?

Regular physical exercise has a profound impact on the body, one of which is enhanced oxygen delivery. When a person engages in consistent physical activity, their cardiovascular system adapts and improves its efficiency. This includes increased heart rate, improved blood flow, and a higher capacity for oxygen transportation throughout the body, particularly to active muscles during exercise.

As exercise is performed regularly, the body undergoes physiological adaptations such as increased capillary density in the muscles and improved oxygen extraction, which all contribute to a more effective delivery system for oxygen. This enhanced oxygen delivery is crucial for endurance performance and overall exercise capacity, allowing individuals to perform physical activities with greater efficiency and less perceived effort.

In contrast, decreased energy levels and a lower metabolic rate are not effects typically associated with regular exercise; in fact, regular exercise tends to enhance energy levels and support a healthy metabolic rate. Increased risk of injury is often associated with improper exercise technique or overexertion rather than being a direct outcome of regular physical activity when done correctly. Thus, enhanced oxygen delivery stands out as the correct and most relevant answer to the question.