When applying from with Canada for sponsoring a spouse, do they let you know when to go for it, (Medical) or do you do it before the application is submitted?

We applied in June and the instructions said the medical would take place during the second phase of the application process.
However, our forms were returned and we were told to take the medical BEFORE our intital application. You can download the forms from the CIC website.

The medical is pretty easy, you should practise for the 'holding your breath for 60 seconds' test though, that was pretty hard.