When shooting outdoor activities, the photographer often has many choices as to how he/she wants to operate the camera. Program mode, Aperture priority, Shutter Priority, Manual? Obviously it depends on the scene and how creative the photographer wants to be with images. In some cases, the manual exposure on your camera may be your best bet.
In the case of sports activities, you probably want to obtain sharp images for your primary subject but may not need the entire image in sharp focus.
Pre-focusing on the area where you believe the action will occur and setting your camera on manual exposure may get you the shot that you want. Taking a test shot in program mode will often give you a starting point of a well exposed image. You can then adjust your shutter and aperture to your desired settings and get the best of both worlds. You can deliberately blur a section of the image, or leave everything in sharp focus.
Remember, when shooting certain sports you may need a very fast shutter speed (> 1/1000 sec) to freeze action. In most cases, leaving your camera on Auto ISO will allow a reasonably exposed image. This also helps if clouds start to roll in on a otherwise sunny day. If you are new to action photography try going to a park one day and shoot a baseball game. Go to a school event for a football or soccer match.
One additional tip would be if you are shooting at a pool. There are a lot of reflective surfaces, so you may want to change your metering mode to partial or even spot metering when selecting your subjects. Carefully choose your focus point in your camera.
With a little practice, sports images can be fun and produce great images!
The more practice the more fantastic the images will be!