Without question, the Barbie-themed birthday bash we just threw for the Wee Lass was infinitely more stressful than embarking on – and sticking with – the P90X program we started 8 days ago.

(And that just gives you a clue as to how challenging that party was to pull off. Let’s put it this way: Our Barbie-for-hire was circling Jersey City in a taxi loooong after the guests had arrived. Good thing the girls were in full-tilt freakout mode when she finally showed up. So sweet.)

But back to mama-fitness. I won’t pretend for a second that P90X isn’t hard; it’s grueling. I think the shortest of the 12 workouts is 58 minutes. That’s much longer than I’m used to exercising, and when it comes to intensity, much more akin to working out with a trainer than winging it on your own.

Oddly, I’m really loving it. Maybe not the Yoga X so much. That’s a killer. And the Ab Ripper X is definitely not my idea of a good time. But I really like the program as a whole, and I feel such a huge sense of accomplishment when I power through my session for the day.

This morning, when I was changing from PJs into my workout clothes, I thought I spotted the beginnings of ab definition. Sadly, it was just a few tiny bruises – no doubt from smacking myself with a dumb bell during one of the routines. Still, for once after delivering the tot-let five years ago, I think bonafide tone in my midsection is actually in the cards.

We’re only on Week 2 of a 12-week journey, but I’m digging it. Yesterday, in the three-way mirror in the fitting room of Target, as I tried on a few tops and sweaters and eye-balled my –s in a pair of tight-ish jeans, it was all good. More hard work, and it will be even better.