Kelly:
You could do this in any way that feels organic to you!
I think last time I tried it I planned to do cardio one day, then Slow & Heavy lifting the next, then cardio, and on like this alternating.
I like to space it out throughout the week. One reason for this is that the Slow & Heavy pace demands huge concentration. If the kids are in and out asking for drinks and snacks every five minutes, it can be quite off-putting. So, alternating days worked for me. It's also good to alternate if you think that the shoulders are used on more than just exercises designed to target the shoulders. Mine get used a lot during bench presses, etc, so alternating days gave the shoulders adequate time to rest before they were taxed again and so could perform optimally.
But on some days life got out of hand and I ended up doing the entire S & H lifting in just 2 days because I had fallen behind with my lifting and had to squeeze it all in before the designated week came to an end!! Hey, life happens. So, whatever works for you! Actually doing it like this was pretty intense and I got quite a pump!
The Slow & Heavy series did great things for me. I had never been so strong in all my life as when I did this rotation in July. Of course, going back to endurance work after that was a killer! My body had forgotten how! Plan for this to happen and you will be able to handle it psychologically better than I did! It threw me somewhat...
Enjoy!
Clare