The husband and wife team of Nelson Guizzo and Carolina Castellano put their physical fitness to the test. The Newtown couple participated in the IronHike Endurance Series at Mohawk Mountain in Cornwall during the end of September and beginning of October. They hiked 15 miles in eight hours, reaching elevation of about 7,000 feet in the Clingman’s Dome challenge — not bad at all considering the event called for a 12 hour allowance and there was muddy terrain.

Guizzo is 51 and Castellano 46; they just celebrated their 22nd anniversary. Avid outdoor enthusiasts, they have hiked in New Hampshire’s White Mountains, in the Grand Canyon, and a few Adirondack High Peaks. Back when they were in their 20s, the couple completed a 60-mile hike in the Himalayas. All of this under their hiking belts, and the IronHike experience was a unique one for both.

“We have done recreational hiking most of our lives but never for an endurance event,” Guizzo said.

Both said the IronHike event was challenging and Guizzo credited his wife for setting the tone. “Carolina has a strong will and a mind over matter that matches very few. All day, people commented on her consistent pace. She is a machine when it comes to experiences where she challenges herself mentally. For me, it was harder and I had more physical discomfort — cramping — than she did. I would say it was a perfect physical/mental challenge for people in the type of shape that we are currently in,” he said.

“The biggest challenge was physical exhaustion and wear and tear,” Guizzo said. “Not only did you gain altitude, but unlike other endurance hikes where they take gondolas down from the summit, you have to descend the same amount, which puts a lot of strain on your knees and toes. I would say the downhills caused the most pain.”

What’s next for this hiking couple?

“Carolina and I are recent empty nesters. We have made a goal to be 46ers, which means we want to bag all 46 high peaks of the Adirondacks. In addition, we plan on doing the next IronHike event,” Guizzo said. “We may try a relay team next year.”

This was an inaugural event with limited participants, and Guizzo anticipates that once it becomes a fully-registered 300 person event, it will be even better.

The IronHike Endurance Series blends hiking, trail running, camping, and extreme endurance in a single or multi-day format. Participants picked from four events, each with different distances, elevations, and time limits. In addition to Clingman’s Dome the offerings were Denali (43+ miles, 20,825 elevation); Everest (61+ miles, 29,155 elevation); and Olympus Mons (152+ miles, 72,590 elevation).

The IronHike Endurance Series is the creation of John Kolker, a sudden cardiac arrest survivor, and passionate hiker.

Sports Editor Andy Hutchison can be reached at andyh@thebee.com.