I've never had much trouble getting up and going to work out. I just kinda do it, even if I'm not feeling it. Now that I'm pregnant, I feel like I'm losing that. I'm just so tired! I've played tennis every day this week and that's been awesome, but masters starts in one minute and I'm in bed. So. Blah. Not sure where I'm going with this. I guess I'm frustrated with myself. I'm trying so hard to not gain a bunch of weight, and this isn't going to help.
Here's the thing about growing a baby: your body is now working literally 24 hours a day at something on top of your regular life. So you are going to be exhausted. You have to respect that and give your body some rest. You can still work out, it might just be for fewer days or minutes or less intensity. Flexibility is the name of the game, so hang in there!