Thanksgiving day is also a day I don't have to work but do have to eat a lot which pretty much means it needs to be a long run day. That run needs to happen before the food happens for obvious reasons. I have very little interest in participating in the cooking part of the day. Others might want you to help with all the cooking of it. How do you make that run happen.
-State early on that you will be needing to get your run in that morning(because well you have to.) This will keep everyone's expectations low for you doing any cooking that morning.
-Get up and out the door before there is much going on in the kitchen.
-If you do pass someone on the way out the door just say "I'm going for a quick jog and will be right back." (30 minutes, 3 hours whatever)
-Get yourself back about an hour out from dinner. Time to shower and dress somewhat appropriately. No one wants to be stuck next to you at the dinner table after you have been running for several hours. If you miss calculate your time and can't fit a shower in before dinner at least change and sit next to the scented candle.
-Fully enjoy Thanksgiving dinner. You just ran double digit miles, eat all you want.
-Head up the clean up crew. Don't be the jerk who didn't cook or clean.
-Foam roll and nap.