I Have No Doubt That This Is Gonna Hurt - MDTBL #3

So I've been going to the gym for about two weeks now.  No big deal, right?  Hey, for someone who has an easy time maintaining bad habits and hard time even starting good ones, it is a big deal.  Last Monday I met with a trainer and he gave me a rundown of what to expect if I decided I wanted to start a regimen, including a workout session.  The first day I had gone back to the gym and done some cardio I thought, Hmm, I guess I'm not as out of shape as I think I am.  I was wrong.  Dead wrong.  Just because I can sweat it out on the elliptical for a good 45 minutes and not feel like I'm dying doesn't mean I'm in any kind of shape.  The trainer took my weight and BMI - I weigh 167 pounds (I was only slightly surprised the number was that high, but I guess all the drinking I did over the summer caught up with me,) and my BMI is at 39%.  That means this body of mine is 39% fat.  Ew.  (Thank God I'm pretty.)  Apparently I'm in the danger zone - for my height and age, the ideal BMI range is 18-23%.  Okay, take the information, process it, file it away and keep moving forward.
Once we had gone over the basics, we went into the gym and this guy had me doing all kinds of funky exercises that definitely had me feeling like I was going to die.  Leg lifts?  Okay, not a problem.  Squats with the yoga ball?  I can handle this.  Jumping jacks?  No big deal...yes, yes this is starting to be a big deal....the mountain climber?  (You know, when you hit the ground and alternate bringing each knee up to your chest.)  Umm....you want me to do 30 seconds of these moves, continuously?  Fuuuu....
By the time he was done with me I was covered in sweat and completely out of breath.  But this is a good thing. I need someone teaching me these types of exercises and encouraging me to keep going when I want to quit.  People like me are the reason fitness and weight loss are billion dollar industries.
Let me stress, again, that I have no desire to be "skinny," to look anorexic, or to be a size zero.  Nor do I have any desire to have 6-pack abs or "ripped" muscles on any part of my body.  I mean, when the trainer asked me if I had any questions, the first thing out of my mouth was, "I'm not going to lose any of my curves, am I?"  I love my ass and hips - they're what I have going for me.  He laughed and told me no, the goal is to get me a bit leaner, more toned, and healthier.  Sounds good to me.
I just have to keep reminding myself that yes, this is going to hurt.  It's not going to be easy.  But it's going to be worth it when I can run up the 3 flights of stairs to my boy's apartment and not want to pass out once I get to his door.  It's going to be worth it when instead of being mildly aware of what my body looks like from certain angles during sex, I won't be concerned at all.  It's going to be worth it when I have more energy and even more confidence than I already do (which will be hard to top anyway.)
Yes, Dana, this is going to hurt.  But it's going to be totally worth it.