Weighing 115 pounds as a high school sophomore, it was clear to me that the easier (and safer) path to athletic success followed a cross-country trail, not a football field.

I never did find much success, but made the varsity as the seventh man on a seven-man team. More importantly, I built friendships with my teammates, learned proper training principles and still relish that sense of camaraderie we shared through grueling workouts in the woods on rainy fall afternoons.

We all learned that cross-country runners were tougher than football players.

Sean Osborne is giving me - and all those old cross-country runners like me - a chance to relive those experiences with a new race series, the Wisconsin Trail Assail, starting in May.

The six-race series includes 5K and 10K cross-country races in Waukesha County Parks: Menomonee Falls, Nashotah, Minooka, Fox River and Muskego. The series concludes with the championship race in Nashotah Park on Oct. 5. You can find the schedule here.

The races will have separate divisions for elite runners and high school athletes, plus an overall series championship.

A real estate executive, Osborne created the series as part of his side business, Silver Circle Sports Events, which he launched to put on a mud run and 5K as part of Summit Days.

"Waukesha County is excited to bring the Wisconsin Trail Assail series into our park system," Waukesha County Executive Dan Vrakas said. "With over 8,000 acres of park and open space, we pride ourselves in providing people opportunities for outdoor recreation, which improves and maintains their physical and mental health and well-being."

Although he didn’t run cross-country during his high school years at Waukesha South, Osborne has fully embraced the concept. The races will have the same large, open-field start, the dash to the trail and the wide-open finish.

It’s the set-up that Osborne saw watching his son run cross-country last season at Oconomowoc.

"I never realized how big cross-country was in the schools," Osborne said. "We just loved it. I realized there aren’t a lot of cross-country events for adults who ran in high school."

Osborne, 43, came to running and the trails much later, after college at the University of Wisconsin – Whitewater and a stint in the Navy.

"I never participated in high school sports," Osborne said. "I didn’t start running until I was 29. I got fat.

"I committed in a meeting that I was going to run the Chicago Marathon and I did it, and here we are 14 or 15 years later. Running is an awful sport to start. It’s hard on your body, hard psychologically. But it is addicting."

Running led Osborne to swimming, then triathlons and the 2012 Ironman Wisconsin, which he finished in 14 hours, 46 minutes.

His triathlon coach, Dwight Sandvold, from Fitness and Sports Training of Wisconsin, encouraged him to get off the road. He gave it a try in Nashotah Park, which has a collection of trails totaling six miles.

He was hooked after the first mile.

"There is nothing better than running in a park on groomed, tree-lined trails," Osborne said. "It’s cool in the shade. There’s wildlife, not a lot of people. It’s just a great sense of freedom when you’re out running. Man, I wish I would have run cross-country in high school."

More options: While Osborne built his series to mirror high school races, runners have a number of options to race on the trails. Wisco Trail Runs offers seven events around the state, tied to the Wisconsin Off Road (mountain bike) series.

Several groups host races at Lapham Peak, in the Town of Delafield, starting with the Bear Trax on April 28, Prowl the Peak in early August, and the InStep Lapham Peak Marathon and half marathon Sept. 14.