Bernard Lagat never thought he’d be here. Specifically, in New York City, preparing to race a marathon this weekend. The now-43-year-old made his name in the grueling 3.5-lap sprint of the 1500m—a discipline in which he earned two Olympic medals and three World Championship medals—and, later, the 5K.

In 2007, Lagat captured dual world titles in both events—surely, the pinnacle of a glittering competitive career. But despite his best-laid plans, retirement doesn’t seem to be in the cards for Lagat just yet. “I used to say my retirement would be in 2013 after the London Games,” he says. “I did everything I could do to sacrifice.” Yet he kept competing.

He won the 5K at the 2016 Olympic Trials at the ripe old age of 41. In the Rio final, he placed fifth and set a masters world record of 13:06.78. “I’m looking at myself like, that is a masters world record already. Am I going to hang everything up and be done?”

The answer was no, and, much to the delight of his long-time training partner Juan Luis Barrios of Mexico, his next mission was to conquer the marathon. He also has a peer to catch in the U.S. masters rankings—Meb Keflezighi, who broke the American masters record at the 2015 New York City Marathon in 2:13.32, before lowering it further to 2:12.21 with a runner-up finish at the 2016 Olympic Trials Marathon in Los Angeles.

While Keflezighi, 43, is reportedly considering his own comeback for the 2020 Olympic Trials, he’ll be in New York to run purely in a brand ambassador capacity and has offered plenty of advice for Lagat via text message.

“[I asked Meb about] how, when he was getting older, how was he able to handle the day-to-day training while hanging out with his family?” Lagat says. “Mentally, how do you get yourself to go out there? What do you tell yourself, how are you handling the aches and pains?”

Lagat admits he runs far less mileage than most marathoners, including Barrios, and that he still struggled to adjust to the higher training volume. “Coach [James Li] is very cautious not to make me do so much because he knows if I do too much, it will be counter-productive,” he says. “I might get injured, I might get tired. We average around 60 to 75 [miles per week], so for marathon training, that is nothing. Some guys get that in two days! My training partner is hammering between 110 and 120 every week. That would just put me in a bad position. I know my limitations for doing too much.

“I found I was struggling a bit at the beginning, getting tired from the volume and intensity. It took me a long time to get past that hump to where I felt like I can actually recover. My last month in Flagstaff, I felt like I’m enjoying this now. Sometimes we get aches and pains in the calf or the hip, you take a day and ice. When I trained for the 5K, it was the same thing. When I need to take a day off, I take a day off.”

Lagat chose to cancel his buildup races before New York due to a lingering pain in his hip after winning the Peachtree Road Race on the 4th of July.

“It went away in a month,” he says of the hip problem. “I had a fear of, maybe, what if I run another race and get another problem—will I have enough time to recover? I did not want to take any chances, so I scrapped every race I had lined up. But at the same time, Coach Li also twisted the training to make me feel I benefited from training the same way I would from the test run.”

He describes a key Flagstaff workout as an eight-mile warm-up run at six-minute pace (“before, a warm-up used to be three miles”), followed by a 10-mile tempo run in racing flats at five-minute to 5:05 pace (“which is not easy at 7,000 feet”). Barrios, who set his personal best of 2:10.55 this year in Tokyo, has raced New York twice and offered Lagat some perspective on the course, which is generally considered to be difficult.

“Sometimes people don’t want to talk about how hard a course is because they don’t want to scare a person to go out there and run as hard as you can,” he says. “Winning is not in the cards, which is good, because it removes that one thing out of the equation. I am not worried about the gap [to the leaders] as long as I am hitting my splits. Will I be able to get [Meb’s record]? That would be sensational, but to get that time in New York is quite hard.”

Lagat made headlines in 2016 by qualifying for his fifth Olympic team. If his marathon debut goes well, might he consider trying for a sixth team in 2020?

“I cannot say no, but then again, everything would depend on how this race goes,” he says. “Not just the positioning, not just the time I get, but the feeling—do I want to do anything crazy like that for 2020? If I feel, ‘Woah, it was incredible, I wasn’t dying toward the end,’ and I am just learning to train for it, those will be the things I talk about to my agent and coach. That is something I am not closing the door on.”