There are several different ways to approach preventing motion blur. Using the L810's built in flash will help but may not be appropriate for all shooting situations. You could also try shooting in the Sports Scene Mode which was created specifically to freeze motion in active situations. Information on the Sports Scene Mode can be found on page 37 of the L810 manual.
The Continuous Shooting and Best Shot Selector options will allow you to take pictures in quick succession and capture action. Information about Continuous Shooting and Best Shot Selector can befound on page 32 of the reference section of the L810 manual.
The L810 also has Vibration Reduction and Motion Detections feature that can help reduce the effect of camera shake and subject movement. These features are not available with all shooting modes, see page 54 and 55 of the reference section of the L810 manual for more information on these settings.
Another way to reduce motion blur is to increase your shutter speed. The L810 does not allow you to manually choose your shutter speed but if you increase your camera's sensitivity to light (ISO) the shutter speed should speed up. Changing your shooting mode to Auto (not Easy Auto) will give you the ability to select your ISO sensitivity in the L810's shooting menu. Selecting a higher ISO setting will allow the camera to use faster shutter speeds thus reducing the likelihood of motion blur in your action shots. See page 33 of the reference section of the L810 manual for information on changing your camera's ISO sensitivity settings.
For an informative article on shutter speed and exposure see this page on Nikonusa.com:http://www.nikonusa.com/en/Learn-An...