Warming up and cooling down is a vital aspect of performance and should be a part of every exercise regimen, training program, or competition. Failing to do both can result in injury, unnecessary strain, and lowered performance.
Warming up aims to reduce muscle stiffness and gradually raising body temperature. This is best accomplished with dynamic stretching exercises and helps lead to warm, relaxed muscles, decreased resistance, and increased blood flow throughout the body; producing improved focus for your event.
Cooling down allows you to bring down your body temperature and relax and re-align the muscles in your body, preventing strains and injury. This should involve static stretching exercises and aim to remove the lactic acid that may have accumulated during your session, bringing your heart rate back down to resting level.