S1: sports mode faster than AV mode?

I have a S1 and use it to take sports photos. When I set the camera to sports mode (running man), I can get a shutter speed of 1/100 indoors. When I set the camera to Av mode and select the most open apeture, I still can't get the same shutter speed as the sports mode. Is there any way around this?

The reason I ask is because I like sports mode, but everytime I change modes or turn on and off the camera, sports mode defaults overide my changes. I usually set the camera to no flash, and -1/3 ev.

Thanks!