Go with what Mike said.
I dislocated my shoulder when I was doing that. When they took my BP, it was quite low at the time, might have also been due to the shock/situation as well.
If your goal is to get stronger, be healthy and have it last, then dont worry so much and just eat first.
As far as PWO eating.
Id have to dig again, but I remember reading that your body actually dosent even really start digesting/replenish till after the first hour or longer after an intense type of workout. I find some quick carbs is the best, and if its got protein, even better.
If youre feelin extra tired, try a tall glass of milk and a glass of water, then a meal afterwards. I think Shakes would be better saved for later as well, after the first hour or so. I usually just wait till my body is cooled completely, so stretch, shower, prepare my meal, then eat. Usually takes me about an hour or so includin commute.