It isn’t often you get to correspond with a marathon finisher, and Paul Gouthro of Lynn certainly has a tremendous story to share.Gouthro ran his first marathon last October, the Marine Corps Marathon in Washington, D.C., and achieved his goal of completing it in under four hours.”A sub-4 time was certainly doable, but I had to run it just right,” Gouthro said. “I checked my qualifying time for Boston, and at my age in 2012 I’d need 3 hours 40 minutes. I put that goal aside for another time and set my sights on sub-4 this first time.”Gouthro has known challenges before, as he is a Marine veteran. (Also, during his training last summer, he sustained a hip problem, trochanteric bursitis, that was relieved with a cortisone shot, a week of rest and a gradual re-start.) He currently works for General Electric in Lynn. His wife Patty, a West Lynner, and daughters Christine and Caroline watched him in the marathon. He met other runners from GE on marathon weekend (the marathon took place on Sunday, Oct. 30 at 8 a.m., just below Arlington National Cemetery).”Our shirts had GE Veterans and Athletes Program on the front and a big GE meatball on the back,” Gouthro recalled.He noted a North Shore connection to the H3 and H60 models of Presidential helicopters that flew over the Potomac all weekend.”Both Presidential helicopters are powered by GE Lynn engines!” he said.Gouthro’s goal meant running a 9-minute pace for each of the 26.2 miles.”I think the first time I checked I was +4 minutes to my 9-minutes per mile rate,” he said. In subsequent checks, he was plus-five ? then plus-six. His highest margin was plus-seven.Gouthro made stops so he would not go without sustenance.”I was careful to drink and eat along the way,” he said. “At mile 8, I actually walked back and forth behind the tables as I drank a full bottle equivalent of Gatorade.” At a food stop between the 12th and 13th miles, “I found my favorite flavor of GU, ‘Jet Blackberry,’ and ate two packets, stuffing two more packets in my pockets,” he said.Yet the proverbial wall hit around miles 22 and 23.”I tried talking to myself that I wasn’t in pain, but it didn’t work,” Gouthro said. “I tried thinking of other things, but that (didn’t) help much either. The pain got worse. It was bearable, so I continued to run through miles 23 and 24. By mile 25, the pain was excruciating.”So close ? and so far. It was time for a reassessment.”The only thing that helped was to do what I didn’t want to do, and that was walk,” Gouthro said. “I wasn’t measuring my margin anymore. I was just focusing on getting around the pain and finishing the last two miles.”Yet he found that he could mix in running with walking ? and then got the ultimate second wind.”When I finally saw the cutoff to the finish line, I just kept running,” he said. “I knew I had one more challenge ahead.”While the final 0.2 miles of the marathon are uphill, Gouthro said he navigated it with no trouble, drawing motivation and inspiration from seeing the Marine Corps memorial of the Battle of Iwo Jima ? and the finish line.”The race time clock read over 4 hours when I saw it,” Gouthro said. “But I just kept running as fast as I could until I crossed the finish line. My time would be determined by the electronic chip in my bib number, not by the race clock.”So, he said, “As I crossed the finish line, I pressed the stop button on my wrist Garmin. I looked down and couldn’t believe it. I had done it. 3:58.40 ? sub 4! My official time was later posted at 3:58.31.”Gouthro trained using the intermediate method of the Hal Higdon marathon program. He cross-trained at the Peabody YMCA through instructors who included Mina Perry (Pilates), Kelley Annese (yoga) and Cheryl Cormier (Zumba).”I’ve been through some tough physical training before, like Marine Corps boot camp at Parris Island, but Mina’s classes surpassed that for me,” Gouthro said.He also appreciated the training runs.”One Sunday morning during training it was forecasted to be hot s