Summarize:

Warming up before a race helps you give your best performance and prevents injury. Jog for about 10 minutes to warm up your muscles, then do some light stretches. As part of your warm up, do some dynamic stretches, such as high knees, butt kicks, squats, reverse lunges, and alternating side lunges. It's tempting to sprint out of the starting line so you can secure the lead, but that's a mistake. Running too fast at the beginning of the race will tire you out sooner, leaving you little energy to finish the race. Instead, pace yourself so you are able to finish the race at a faster pace than the other runners. Don't let other runners psych you out if they choose to start off fast. Remember, they're going to burn through all of their energy before the end of the race, so you can always pass them later. At the beginning of the race, you'll need to manage your energy levels so that you don't run too fast, which may tire you out too soon. As you progress through the race, you can increase your pace occasionally to pass other runners. However, save your sprint for the end of the race. It's natural to want to run faster to finish first, but tightening your shoulders and face won't accomplish this goal. In fact, clenching these muscles costs you energy that you could be using for a strong finish. Instead, keep your face and shoulders neutral and relaxed. Check in with yourself when you reach race landmarks and release any tension you're holding in your face or shoulders. Sticking close to your teammates can keep you motivated during the race, so try to run as a pack for most of the race. However, don't slow down your pace if you're much faster than your teammates. Practice sticking together when you go on practice runs. When in doubt, ask your coach for advice about where you should be running in the pack.
Warm up about 30 minutes before the race with a light jog and stretching. Start the race at a steady, moderate pace. Keep a quick, even pace rather than alternating between a sprint and a jog. Relax your shoulder and face muscles so you don't waste energy. Run with your teammates for encouragement.