When the Vicegrip Vixens asked me to come skate with them at their latest roller derby practice, I got excited.

No — that's an understatement. I got really excited. Spectacularly, catastrophically and uncontrollably excited, on the level of a crack-addled, caged-up monkey. Three things I like — tattooed women, hand-to-hand (or elbow-to-ass, knee-to-throat, etc.) combat and potty-mouthed humor — were going to be there, and in force, catering to my most adolescent desires. The days leading up to the practice were filled with quivering anticipation. I almost needed a grandpa diaper.

Kidding. Anyway, the bout was not to be. I had mistaken an invitation to skate with these women as a chance to rub elbows with them, so to speak. But when the Vicegrip Vixens, one of four teams comprising the Tampa Bay Derby Darlins, said I could join them for practice, it was just to let me skate beforehand, not during.

Not that I mind. These gladiators-on-wheels need all the practice they can get. No slight intended — many are experienced and talented skaters. But in terms of time, the league is in its infancy.

The Tampa Bay Derby Darlins, formerly called the Tampa Tantrums, started in mid-2005. At first, the Darlins were just a loose aggregation of women with similar interests. Earlier this year, the pack was split up into the Black Widows, the Switchblade Sisters, Cigar City Mafia and the Vicegrip Vixens. Their first contest, held at the United Skates of America in Tampa (where the Darlins are practicing tonight), was only two months ago. More tilts are scheduled, one per month to be exact, culminating in an October championship match.

Around and around the rink I go, hunched down ("helps maintain your center of gravity," a Darlin shouts as she speeds past me), which forces me to stare at anonymous asses, while feeling and looking like one myself. The real practice, the one where people get hurt for reasons other than simply wiping out on the rink, was a girls-only affair.

There's not much to know about roller derby, as the rules are pretty basic: a group of women skate in "jams," two-minute races in which two opposing groups of "blockers" (five per team, including two "pivoters") try and stop their opposing "jammers" from speeding through the pack. Kind of like a one-on-one race, albeit with living, breathing, malicious obstacles.

Think of roller derbies as a higher class of mock fighting. But the injuries can be very real, with bruises and broken bones a common occurrence. EMTs are kept close by at matches, even though the girls come equipped with pads and helmets. On occasion, real fights erupt, which, like NASCAR, are always good for getting the crowd going.

Little wonder why I'm not allowed in the rink during practice.

"You look like a liability," Eve L. Twin scoffs at me. She is a 33-year-old lifelong roller-skater and mother of two who serves as co-captain of the Vixens. She just drove up from Sarasota, and if she comes off sounding a little testy, it's not because of the traffic or construction she just endured on I-275.

"I don't get enough pushing people around at work," she explains of her attitude. Is she joking? Half-joking? Is she being completely literal? Who knows.

Sarcasm and cynicism abound at the rink tonight, so it's hard to tell what or whom to take seriously. That seems to be a requirement of roller derby culture, and indeed, most girls have a "whaddya want?" kind of attitude that may be taken as either precocious and playful as a month-old kitten, or ornery and snide as a nihilistic ticket-taker at the county fair.

Another hallmark of derbyism: tattoos. Most women have them, and most don't mind showing them off. The tats are usually of the vintage '50s variety, which goes along with the whole Bettie Page aesthetic that is prevalent at practice tonight.

"I have them on all my toes," says Frieda Killigan of her ink. Killigan, whose body is tattooed in various strategic places from head to toe, works in the operating room at Sarasota Memorial Hospital, a fitting workplace for someone who gets to see a fair share of injuries on the wooden rink.

Why the toes? "I can't have them on my knuckles," she says in a withering "no-duh" tone. She has H-O-P-E inked on one foot and F-E-A-R on the other.

Eva Lynn Tint chimes in. About the tattoos that seem a requirement for participating, she says, "There's this image of roller girls as being edgy — how better to show off your punkness?"

True, tattoos don't necessarily scream out "linguistic anthropology major," which is what Eva is. The 24-year-old St. Pete resident attends USF, though she also finds time to work at a commercial real estate firm as well as be a Vicegrip Vixen. She just departed work, actually, to be here at practice, though she's not on wheels tonight.

She indulges me by answering the following questions, which are probably kind of inane (but then, doesn't my fearlessness in asking stupid questions show off my punkness?):

Q: What do I need to know about roller derbying?

A: Doors don't hurt after you run into them for the sixth or seventh time.

Q: Do y'all have prior experience as skaters?

A: About 10 percent do.

Q: What's with the stank in here (referring to the United Skates of Tampa)?

A: Not only are there an enormous amount of skates without feet in them, but hockey guys leave a horrendous stench. I think that adolescent boys — they don't realize they're at the age where they need to use deodorant.

Q: Who succeeds at this? Big girls or little girls?

A: Little ones. It depends, though, because everyone has unique strengths and weaknesses. Big girls push harder, but they fall harder, too.

Q: Like Super Mario Kart? I love that video game!

A: I love it too. Yeah. Bigger skaters are like Donkey Kong. Little skaters are like Toad.

The Black Widows vs. The Cigar City Mafia, Sun., July 23, 6 p.m., United Skates of America, 5121 N. Armenia Ave., Tampa. $10. www.tampabayderbydarlins.com.