40d + Sport

For fast moving sport is Aperture Priority, Al Servo & Central Focus Point the best combination to use on the camera?

It's a good start. I use M and set the shutter speed and aperture and adjust iso if needs be.

As Mike said, I also suggest that you use M. That way you don't risk the shutter speed getting too slow in changing light. For example, at a night high school football game (US) the lighting is usually terrible but also changes form the 50yd line to the end zones. By using manual you can be sure that your aperture and shutter speed will not change. It's quick and easy to change your ISO. Same with a baseball game where each base can end up in a different light.

I always shoot in manual as well, but I do that for everything I shoot. Al Servo and centre point for tracking subjects.

Or changing subject: How the subject affects the exposure & why manual keeps me worry free: Post #47

First set the f-stop & shutter speed you need. Then adjust the ISO. Need an exposure crutch?

If you can, try Custom Function C.Fn-13 (1) to put the focus points on the joystick (multi controller) which makes it easy to switch when things are moving fast.

AF Point selection for sports

If the light is even, I've had decent luck in AV and ISO 400, and bumping up the ISO when the light starts to fade. If you're shooting in RAW, I've found it's better to meter for the highlights. It's easier to add detail back into the shadowed areas in RAW post processing, but once the highlights are blown out, there's not much you can do for them.

What I have seen is that even though your camera will say that highlights are blown out, there aren't blown out in reality and you can recover them unless you are way over-exposing. if I under-expose and adjust in pp, I get too much noise in shadow area.

I prefer manual exposure mode, AI servo and center AF point.