The document discusses how to properly warm up before exercising or playing sports. It states that a warm up has two parts: joint mobilization and activation. Joint mobilization involves moving different joints like ankles, knees, hips, and shoulders using motions like circles. Activation prepares the body's locomotive, cardiovascular and respiratory systems through exercises like running with high knees, side shuffling, and jumping. A sample warm up game called "chains" is also described.