What do they do in a sports physical?

Screen. A sports physical is designed to screen the athlete for fitness to train and compete in their sport and also look for pre existing injuries/conditions that could be a detriment to them.
History and Physical. You should be asked about past medical history, including any heart, breathing, muscle problems, injuries, or family history of heart problems. You should get a head to toe exam, including a hernia exam for males. You will have your weight, height, and blood pressure taken. You may have urine tested, you might get blood tested depending on the doctor and the requirements on the form.
SPORTS PHYSICAL. A sports physical is not much different than a regular physical. They do pay particular attention to the heart and lung exam. Additionally, particularly in youth sports, the musculoskeletal system is a focus area, particularly looking at the spine and knee joints. Most current exams have baseline neurological testing for concussion.
Sports physical. Includes a thorough history and physical exam to allow you to safely participate in activities and access any risks you may have for injury and recommend any rehab/exercises prior to activity. There are a few differences in the exam and history for males and females. http://www.acsm.org/docs/brochures/pre-participation-physical-examinations.pdf.