You never know where you are going when you get that 6 p.m. call from the modeling agency. Your child has been requested for a go see, are you available?

My kids consistently get called to three locations that are obviously full-time photo studios, complete with catered lunch and Moulton Brown hand cream in the bathroom.

The rest? One-time visits to rickety West Village buildings that make me feel like a contender on American Gladiators.

Last week, I arrived at a tiny apartment building. According to the posted signs, you had to buzz up to the third floor and then hold your child's hand climbing the narrow, rickety stairs to what I swear was somebody's rundown studio apartment, being used for the day to cast a Procter & Gamble commercial.

No big deal, right? Except that I had a sleeping toddler in a stroller because 3:15 p.m. is nap time. I had to abandon the stroller at the foot of the stairs (good thing my City Mini is grungy enough that it's unlikely anyone will steal it), and carry my sleeping child up three flights while loaded down with my super-heavy handbag and diaper bag. Try doing that while pregnant and battling seasonal allergies, and you will feel like you just survived the Pyramid when you reach the top.

Once you arrive, immediately locate the person in charge (usually a ridiculously young, beautiful and groomed man or woman brandishing clipboards who obviously considers the masses of children to be a necessary evil – constantly yelling for quiet at a room packed with toddlers is only minimally effective). You get assigned a number, then struggle to find a place to sit while you take off the kids' shoes and wait to be called for weight and height measurements. After the weigh-in, consecutive numbers get called for a brief turn in front of the camera. When we left, it was raining so I ensconced one child under the stroller canopy and draped the other in my emergency windbreaker, then got drenched while running to the car.

Arduous as that experience was, it wasn't any different from the many times I've arrived at the Monroe Center in Hoboken only to find the elevator is out of service; carrying my stroller up five flights of stairs to Monroe Movement Space keeps me in great shape for modeling excursions.

Hey, nobody ever said motherhood was going to be easy. It's a good thing I was an athlete for many years before becoming a parent; all that strength and coordination training is coming in handy. It also explains the standard Hoboken mom gear of yoga pants and athletic shoes; when we take the kids out and about, we never know if we are going to wind up getting an impromptu workout.

To read more about what makes Kathy Zucker tick, check out her blog at http://momcondoliving.com/ and follow her at http://twitter.com/kathyzucker