I'D BEEN a gym rat in high school and college, doing everything from practicing basketball to lifting weights.

So why, a few weeks back, was I so apprehensive about working out at the new Gold's Gym in Fredericksburg?

After years of talking about needing more exercise, nudged by pants waistbands that were forever shrinking, it still took a gym opening a few hundred feet from my back door to force action.

But as I picked up my membership card and packed my bag for the initial visit, I was more nervous than a teen pinning a corsage on a prom date.

For two main reasons.

Main Reason No. 1: The whole notion of working out has changed since those gym-rat days.

Back then, you shot hoops, ran laps or pulled or pushed a few weight machines up or down. Simple.

These days, you walk in to find a whole host of automated machines with computer brains that you pedal, stride on, walk up, walk down, jog atop and more.

There are buttons to push, heart monitors to trigger, "warm-up" and "fat burn" settings to decipher and even a little clip you put on your T-shirt so the machine has the decency to stop when you fall on your keister.

And there are machines with screens little or large that'll let you sweat to "Oprah," or, in a darkened room, the latest Batman movie.

Or worse, several different levels and types of weight equipment, from free-weight stations I recognized to others with various handles and cables designed to tax everything from your glutes to your brutes.

Main Reason No. 2: the deplorable condition of my physical fitness.

While no one has ever thought to call me slender, there were days when I could show up in a swimsuit without having the terms "stocky" or "love handles" coming to mind.

There were also days when I'd been working out enough or simply working enough to heft weights that didn't scream anemic.

The bottom line of this concern was the fear of sauntering into the gym only to be surrounded by people so fit, trim and physically powerful that I was lumpy clay to their chiseled steel.