Final answer:
A warm-up should include dynamic stretching with purpose, targeting muscles and joints to increase blood flow and reduce injury risk, rather than static stretches which can be harmful if muscles are not yet warm.
Step-by-step explanation:
The stretching and mobility part of a warm-up should be conducted dynamically with purpose; focusing on both muscles and joints. The purpose of this part of the warm-up is to prepare the body for physical activity by increasing blood flow and reducing the risk of injury. The practice involves controlled, purposeful movements that mimic the exercise or activity to follow. While stretching, you are primarily working on muscle fibers, but the increased blood flow and movement also benefit the joints. It's essential to avoid static stretches as they can lead to injuries when the muscles are not yet warm. Dynamic stretches, on the other hand, help to gently increase the range of motion and prepare the body for the demands of the workout.