These are my 1st ever decent action shots taken with an A57 and Minolta 70-210 F4.
shot in burst mode. I think I need to read up on the focus settings and the metering modes available on this camera.
Just in case the exif was stripped, heres what I was using. 1/400, 210mm, ISO 160, f4
It does look like the camera wasn't well focused on the subjects so I agree you might need to figure out your focus settings. Something looks a little off with these photos but I don't know if it's just the focus or some processing or lack of sharpness. I'd think about adjusting the camera settings to be able to get a faster shutter speed.
The problem I think with continuous shooting is that it doesn't look like it adapted to the fact that the subject is moving closer to you so you ended up with the last couple of shots of each series with subjects cut off. For the last two I might have flipped the camera to a horizontal position to keep both runners in the frame, or stayed vertical and reframed the shot to just get one runner.
If you can anticipate the action and get set and ready for the action/athletes to come to you, that can help get a good shot. If you go early you might get time for test shots, maybe during warmups etc. Shooting sports involves figuring out the timing - and lots of practice.
Shutter speed is too low, try and work with 500th-1000th you can bump the iso up as well, 400-640, and f stop to 5.6. However these look like the camera wasn't focusing on anything. The angle you chose for the shots is good. Just have to work on sorting your exposures and camera out.
If you were to shoot these at 640iso, get your shutter speed up to over 500th second and f stop around 5.6, you will still get the separation between subject and background that you are looking for. Faster shutter speed just stops the action, higher iso allows this to be possible. Try playing with exposures even if it's just shooting a picture of a static object and see how changing the iso allows you to change the shutter speeds and f stops.