Let it begin

So, as many on my Facebook saw, I have decided to run a half marathon. For what plausible reason, I have no clue. This is not a new desire. Truly, its not. But to finally really, honestly decide to do one is a new thing. I think I'm getting senile.
I started working with a trainer this week to get me in shape for running. For those of you who don't know me personally, round IS a shape, dangitall! Ok, I'm not round. Curvy as all creation, yes. But some of those curves need to become well-defined muscle before attempting to combat 13.1 miles of pavement. At one time. 
Being the good trainer that he is, one of the first things he asks me is what my running experience is. I admit I walked a 5k back in August. Oh, you meant really running? High school, junior high, maybe the Paleolithic Era. Possibly the Jurassic. I'm not sure, it's been awhile. To be fair and honest, I was a damn good sprinter back in junior high and high school. 100m, 200m? I was your girl. 4x100m relay? There's a reason I was the anchor. I couldn't be touched.
Fast-forward 25+ years and 4 kids, and the story is a bit different. I'm an overweight, yoga-doing, twice-a-week-around-the-block-walker with an avid sweet tooth. What in the name of God's green earth possessed me to actually want to attempt a half marathon? Senility or some other serious mental incapacity is all I can claim.
Anyhoo.
This is the end of my first week of training. Things hurt that I didn't know existed, or that I thought would be part of training for running. Why in the nine hells do my ARMS hurt? And my neck? And who knew you used your back and abs when you ran? Hips and legs I was expecting, but my arms? Really? REALLY? Ugh.
I have done more walking lunges in the past 5 days than I have in the past 5 years. Pushups? I lost count. Russian twists? I didn't know my abs were capable of doing 1 of these, let alone the 45 I have done this week. Mountain climbers? My shoes and legs hate them. My legs will adjust. My shoes will just have to suck it up. Bridges and hamstring curls? I collapsed after 20 seconds. I kind of thought my yoga practice would have me prepared for some of these things, but I was dead, dead wrong. And I haven't even ran a step yet.
I have also learned how to correct my form during certain exercises (especially butt-kicks). I have learned that my body is capable of more than I thought. I'm learning to enjoy my evening soak to soothe said muscles. And I'm learning to muzzle that inner critic when she says I can't do another rep. That inner critic can go jump off a cliff right now. I have a long way to go, but I'm pretty sure I don't want her along for the trip.