Explain why proper body alignment is important, and give an example of how it can positively influence your performance during a workout or activity

Proper body alignment or proper posture is important in many ways. First, it gives an impression of confidence. The other benefits are for your health and metabolism. When working out, you put yours muscles and ligaments to great pressure. When you do this in proper posture, your body will execute the exercises more efficiently with less energy than needed. This will prevent you from accidentally pulling any muscle. At the end of the day, your muscles will feel less fatigued than those not executing with right posture. In the long run, this might lead to pains like arthritis and joint pains.

For example, when doing planks, avoid your head and belly from sagging on the floor. Use your core muscles to support yourself. This would prevent spinal compression.

This is true. yes. indeed.