There are definitely some legitimate reasons not to workout out on a given day. The two excuses I will accept every time are you either contiguous or non-ambulatory.
It should be pretty obvious that nobody wants whatever pathogens you’re trucking around in the gym, but there’s a second reason you need to consider. Our immune systems and ability to recover from workouts/stress are linked. Yes, you might be able to still ‘hit the WoD’ hard, but guess what? Your return on that investment is going to be little to zilch. As hard as it might be to take, you’ll make bigger ‘gainz’ from extra sleep and rest.
Next, up I need you to be ‘ambulatory’. If you’re not fit to operate a vehicle, is it really a good idea to put a bar over your head? If you have to be carted across the parking lot in a wheelbarrow, what are you hoping to gain from ‘Fran’?
Ok, all that aside we’ve been open to the public 2009 and I’ve been coaching people with this methodology since 2006. In that time we’ve worked successfully with people with all sort of issues.
A partial list in no particular order 
- Broken wrists, arms, legs
- Torn knee cartilage
- Missing limbs
- Post-rehab training for
- Right Hemicolectomy
- Liver resections
- Knee and shoulder surgeries
- Various Autoimmune disorders
- Cancer survivors
I literally could go on and on, but really in the end the story is the same. If you can get yourself to the gym safely and you’re not spreading the Flu, Noro (or whatever the germ-pocalypse of the week is) we can work with you.
Simply communicate with the coaches, have an open mind and get ready to work.
For more info on the concept see Greg Glassman’s ‘Working Wounded’
http://library.crossfit.com/free/pdf/33_05_working_wounded.pdf
