Michael Greenebaum and Jon Sevel had been running buddies for years, covering some 1,200 miles and three Marine Corps Marathons, when they decided to establish a race on their home turf in Baltimore County. There was never any doubt about which race: a half-marathon.
Despite an odd length at 13.1 miles and a lack of elitist appeal, the half has become a full-blown craze among runners, experienced and new.
The number of those running in general has been booming for the past 15 years. But half-marathons have been the fastest-growing road race in recent years, according to Running USA Inc., a Ventura, Calif., organization that promotes fitness and tracks trends. Many new halfs are being added every year, some with more than 1,000 participants, such as Greenebaum and Sevel's inaugural event, named the Maryland Half-Marathon and planned for May 31 in Timonium.
The pair quickly decided to use their race to raise money for the University of Maryland Marlene and Stewart Greenebaum Cancer Center, named for its benefactors, Greenebaum's father and mother, who is a breast cancer survivor. They thought a charity connection would lure more runners and turn the race fee and pledges into cash for a good cause.
"We thought it would be great to have a local spring half-marathon in Baltimore County," Greenebaum said. "There are 5Ks every weekend, but people get really excited about half-marathon events. You need to train, but they are very doable."
Charitable appeals, organized group-training programs and the growth in the number of female participants are helping to fuel the rise in running, according to Running USA. The 5K, at a little more than three miles, remains the nation's most popular running event. But participation in half-marathons has grown the most - nearly doubling in the last decade to 715,000.
Local runners say the half's appeal is clear. It's a real accomplishment without the aches and time commitment of a 26.2-mile full marathon, which typically takes those who run regularly 18 weeks to prepare for and several days to recover from.
"It's a challenge, and you have to train, but it doesn't take up a crazy amount of your weekends," said Staci Bafford, who began running half-marathons about two years ago. "Plus, unfortunately, my knees do not really like longer distances."
The 27-year-old who lives in Canton is training for the Maryland Half-Marathon. She has run half-marathons before and chose the Maryland race because she is a thyroid cancer survivor and was treated at the cancer center. She wanted to give back, a major reason many people choose to run races.
The length of a race people choose to run is often determined by their running partners, said Rich Desser, who trains with the NCR Trail Snails, a running group that meets on the northern Baltimore County trail. The race distance is often longer than people would undertake on their own.
"When you're on your own, training for a full marathon can seem like a daunting task, and in a sense it is," he said.
"A half-marathon still provides a challenge, but seemingly at a much more manageable level," he said. "When you hook up with a group of friends, or a running group who become friends, and the group as a whole is training for a longer distance, like a half or a full marathon, it is much easier to grasp the training as a more manageable endeavor."
Local race organizers say their numbers show that participation in half-marathons is growing rapidly. The half has become the largest race offered by the Baltimore Running Festival, which is the state's biggest collection of running races and has been held every October since 2001.
The half was added in 2003 and has sold out every year, even though the field keeps expanding to accommodate more runners. Last year, the 8,000 slots sold out two months before the race, and there was a waiting list of 500. The 4,000 full marathon slots also sold out but not as quickly.
Up to 10,000 half-marathon slots will be available this year and more than 1,200 are already spoken for, a 40 percent gain on registration at the same point last year.
Lee Corrigan, president of festival organizer Corrigan Sports, said the races have been grown slowly - particularly the half-marathon - to ensure that they are still enjoyable. Based on runner feedback over the years, the course has been altered so the full and half-marathon runners merge more smoothly; runners have been started in waves so they aren't crowded in the beginning of the race; and walkers have been encouraged to move to the back of the pack.
"One could certainly make the argument that the half really has helped the Baltimore Running Festival survive," said Corrigan, whose company also organizes the Frederick Running Festival and the Baltimore 10 Mile Race.
"It's becoming an incredibly popular distance," he said. "In today's society, it's tough to get all that time necessary to train for a full marathon. A lot [of runners] can do the half with not nearly the time and effort it takes to run a full marathon. And there is something to be said for wear and tear on a person."
He added that half-marathoners, like full marathoners, also get an athletic shirt from festival sponsor Under Armour and a finisher's medal.
In Baltimore County, Greenebaum and Sevel hope their race becomes as popular as the Baltimore races. In the inaugural year, they hope to have 2,009 runners and to raise up to $500,000 for the cancer center.
They'll have a proven base of half-marathoners to rely on.
The race "is a great thing," said Greenebaum. "You can run in the morning, do something good for yourself and the center, and continue with the rest of your day."
Sevel added that the race "is already half full."
Here are some coming half-marathons in this area:
* March 21: The National Marathon & Half-Marathon offers a tour of the nation's capital. Call 866-786-0262 or go to nationalmarathon.com.
* April 18: The Ocean City Half-Marathon starts at the Ocean City Inlet parking lot and finishes at Assateague Island State Park. Go to octrirunning.com.
* April 26: The TriColumbia Howard Life Festival includes a half-marathon and other events, which start outside of Merriweather Post Pavilion. Go to tricolumbia.org.
* May 3: The Frederick Running Festival is a collection of races, including a half-marathon, on a rolling course around Frederick. Call 410-605-9381 or go to frederickmarathon.org.
* May 31: The Maryland Half-Marathon benefits the University of Maryland Marlene and Stewart Greenebaum Cancer Center and starts at the Maryland State Fairgrounds in Timonium. Go to mdhalfmarathon.com.
* Oct. 10: The Baltimore Running Festival is a collection of races, including a half-marathon, around the city. It starts at or near M&T; Bank Stadium. Call 410-605-9381 or go to thebaltimoremarathon.com.