At Houston's second annual Hot Undies Run, I learned something very important: The simple term underwear is now synonymous with boxers, boxer briefs, loincloths, Spanx, spandex, long johns, corsets, thongs, boy shorts. And treasure trolls.

Underwear also comes in all shapes and sizes. Just take my word for it. When over 700 pairs of undies gather around Rice Village to support a good cause and a local running group, you realize for the first time just how many varieties of skivvies there are out there. Well beyond the realms of Victoria’s Secret.

The Saturday event was a two-mile fun run with a quick stop at the Rice campus bar Valhalla for a refueling of Shiner, and was open to anyone 21 and up “with a sense of humor.” Racers were encouraged to vie for The Best UN-dressed award (with prizes available) and to bring new, unopened packages of socks or underwear, for underprivileged boys and girls in the Houston Independent School District for an organization fittingly called Undies for Everyone.

The idea for this sweaty little fun run came from Carissa Thomas, one of the Brian O'Neill (BON) Running Club's officers. Thomas is currently working on her MD/PhD and has close family ties to a wonderful organization, the Children’s Tumor Foundation (CTF). She came across a similar idea benefiting the CTF in Washington, D.C. where residents ran around in the cold over Valentine’s Day in their underwear — so of course it only seemed appropriate to start something similar in Houston. In the record-breaking heat.

In its inaugural year, the race raised more than $7,000 for CTF, but far beyond the money, was the awareness it produced.

BON was launched in the fall of 2008 by Dave Lee — an avid runner and entrepreneur who decided to tie his two passions together. After reading an article in Men’s Fitness about a similar group that epitomized a “fitness culture” in his hometown of Colorado, Lee thought, why not Houston? Sure, the weather may be a bit different than the Rockies, but Houston is social and has a lot of avid runners, so why not?

The loop around Rice is always packed with sweaty runners, but if you’ve noticed an abundance of runners of all levels on Tuesdays, you’ve probably seen BON in action. They meet every Tuesday (rain or shine) from 5:30-7:30 p.m, for a free 5K where people run at their own pace individually or with groups and meet back at Brian O’Neill’s (one of the club’s sponsors) for free snacks and drink specials. Not to mention lots of laughter and great running advice from some of the most hardcore runners Houston has ever seen.

I’ve been given some instrumental advice during my visits to BON — mostly that I run crooked and need to drink more V8. And my doctor agrees.

Lee’s dream in the not too distant future is to expand these free social running clubs to every major city in America. There are already three other local running clubs under this umbrella — CityCentre Running Club (Houston), Goose Acre Running Club (The Woodlands), Berryhill Running Club (League City) — and a fifth is set to launch this September in College Station called Corner Bar Running Club. Later this year, the group will be expanding for the first time outside of Texas to San Jose, Calif., Janesville, Wisc. and Chicago, Ill. – so tell your friends.

Lee is well on his way to making this running club dream come true. And if you know him at all, you know he’ll sure be able to accomplish this task at hand.

For more information about the BON running club, visit the group's website, Facebook or TWITTER and remember, the club meets every Tuesday for free.

So just show up in your running shoes. Underwear optional.

You can read more from Jayme Lamm on her blog The Blonde Side.