Event photography is exciting, challenging, and a great way to get tons of great shots of incredible (and willing) athletes. Part of what makes an event exciting, is the crowd.
When shooting for companies that are sponsoring or running the event, you will need lots of great shots that showcase action, and the crowd. An important part of capturing the crowd is learning to compromise. Sometimes the best angle that you see will not work in a way that includes the crowd. You'll have to decide if that action image is more important, or if one that is slightly less amazing, but includes the crowd, is a better bet.
One of the biggest issues with shooting to show the crowd, is the actual crowd themselves, plus the fact that most events take place in harsh midday light. The crowd will wear all different colors and create a VERY cluttered background. The only real way to deal with this without flash is by using a very shallow depth of field. This looks very professional as well, but will also blur the all-important sponsor signs by the crowd. At times it works great, but it is often tough to get an angle that will allow that super shallow depth of field since you'll need a fairly long and fast lens.
This is when it's best to bring on the flash! At APS we are very big advocates of adding flash to make your photography stand out from the pack, and to create more stunning images. You'll typically want to underexpose slightly so that the crowd is less bright than the athlete. Then simply pop off a flash (or two, three, maybe even 100 if you're Joe McNally) aimed at the athlete. This light on the athlete will make them stand out from the background. It will also make your shot standout from a lot of other photographers.
It's easy to sometimes forget about composition when shooting to capture crowd and action. Try and remember that shots generally look better when the action isn't centered. It often works well if you have course access to shoot at an angle to the crowd so that they will occupy most of one side of the frame, and the action will be on the other side. Say 45-90 degrees towards the crowd depending on lens choice.
Another angle to look for is up high, or getting very low. Both will work depending on where the crowd is to move the action away from the it and gain a better background.
It takes a lot of experimentation, and is always best to scope out the scene first, but if you can master the action/crowd shot, you'll be on your way to becoming a great event photographer! To learn more about event photography including acquiring press passes, networking, and landing jobs, checkout this article here.