Hi Guys,
I was at OASC August last year, the fitness test is a MSFT - Beep Test, you are looking at a minimum of level 9.10, then you do press ups - 60 seconds - minimum of 13, then sit ups - again 1 min - minimum of 35.
These are mimimum standards, they are looking for maximums at OASC, you need to aim for at least level 11 on the MSFT. These targets are pased on younger than 25, the older you get the lower they get.
For the sit ups you need to be touching your temples with your finger tips and then bring your body up until your elbows touch your knees.
There is stacks of information on OASC here -
http://www.thestudentroom.co.uk/forumdisplay.php?f=96