Final answer:
The warm-up should include exercises that gradually increase intensity and prepare the muscles, while the cool-down should include exercises that gradually reduce intensity and help the body recover.
Step-by-step explanation:
A warm-up before an intense activity and a cool-down afterwards are important to prevent injuries. During the warm-up, you should include exercises that gradually increase the intensity and prepare the muscles for the activity. Examples include walking, jogging, cycling, and stretching. The cool-down should include exercises that gradually decrease the intensity and help the body recover, such as walking and stretching.