I tried the settings recommended by DonSchap and have been pleased with the results. These were taken at a stadium with pretty good lighting. All shots were with an A700 and a Sigma 70-200 f2.8 lens.
The backround black sky, which always showed a lot of noise with my 5D is vastly improved.
The kicker is; All of these were shot at ISO 6400
f2.8 1/1000 120mm
f2.8 1/1000 70mm
f2.8 1/1000 135mm
f2.8 1/1000 200mm