I'm relatively new, so I'm wondering of this sounds familiar:

1. Seeing an A+ provider in the afternoon, then at night trying to mask your unbridled joy as you bounce around like a teenager who just got laid for the first time.  
2. Trying to move normally the next day as your entire body aches but you have to hide the pain from your SO lest you need to explain it. And, of course, she wants sex tonight.  

It's odd that sex with a provider causes muscle aches but not sex with the SO. I have a few theories on that, but I'd love to hear some others.

Staying active, exercising, fucking and advil.

END OF MESSAGE

This probably isn't a good idea. You don't want to alter your schedule. You don't want to do anything that isn't normal. Maybe join a gym and start going regularly. Talk about it a lot, until she gets bored of it. Then use it for cover. She won't suspect anything. It will have become part of your normal routine. You could then have a legit reason to have a bag, with toiletries so you can shower at the gym if necessary. Then use it to shower after a visit, she'll be none the wiser.

It's all about being the boring/same olde guy that she knows and has no reason to worry about.  Sudden changes cause worry. Worry causes her to look closer. You don't want that.