The heat will be on at US Olympic marathon trials

“You have to understand what your fitness level is and then make necessary adjustments,” said Desi Linden, who qualified when she placed 10th at the 2014 Boston Marathon in 2 hours, 23 minutes and 54 seconds. “I feel confident that we are pretty well-prepared for it. But 80s, you still need to make adjustments, so we’ll do that when we know the exact temperatures.”

Recognizing that temperatures could reach the 70s or even 80s on race day, Linden’s team, the Rochester, Michigan-based Hansons-Brooks Distance Project, spent six weeks training outside Orlando, Fla. The group had plenty of days with high heat and humidity, and that makes Linden an overwhelming favorite to make the Olympic marathon team for the second time.

The other overwhelming favorite in the women’s race is Shalane Flanagan, the 2012 trials champion and the top qualifier for the 2016 race. The Marblehead runner earned her spot in the field when she ran a personal best 2:21:14 at the 2014 Berlin Marathon.

Flanagan dealt with a stress reaction in her right foot at the start of her marathon trials build-up. After being in a boot for roughly a month, she “pushed the envelop” with her training post-injury. Discussing her trials preparation Friday afternoon, Flanagan described her missed training time as “fairly insignificant in the whole grand scheme of things” and said she was “cautiously optimistic” about the trials. And the weather sounded like a bigger concern.

“I’ve never run in the temperatures that are expected,” said Flanagan, who has a bronze medal from the 10,000-meter race at the Beijing Olympics, which took place in hot and humid conditions. “I wouldn’t classify myself as a great heat runner, but I wouldn’t say I’m terrible. I’m just going to listen to my body as much as I can.”

The strong contenders for the third and final Olympic berth include Flanagan’s training partner Amy Cragg and her former training partner Kara Goucher. At the 2012 Olympic marathon trials in Houston, Goucher placed third, while Cragg finished a heartbreaking fourth. Entering the 2016 trials, Cragg owns the third fastest qualifying time (2:27:03), while Goucher won a couple of half-marathons at the end of last year with her fastest times since 2012.

“It has given me so much confidence training with Shalane,” said Cragg. “Every day we do just about everything together, and she’s someone who consistently gets it done.”

The men’s field presents more uncertainty and intrigue than the women’s, especially since Galen Rupp will make his marathon debut at the trials. While best known for his accomplishments on the track, including a silver medal in 10,000-meter race at the 2012 London Games, Rupp is seen as a serious contender for marathon trials title. He qualified with a 1:01:20 half-marathon at a low-key race in December, and ever since his participation in the trials has been the talk of the distance running community.

Some of the best marathoners excel in their debut at 26.2 miles. (See Flanagan’s second-place at the 2010 New York City Marathon in 2:28:40.) And some walk away humbled by the experience and uncertain if they will race that far again. (See Meb Keflezighi’s ninth-place finish at the 2002 New York City Marathon in 2:12:35.)

Now, Keflezighi, 40, is a veteran who has New York and Boston marathon titles on his résumé, as well as an Olympic silver medal in the marathon from the 2004 Athens Games. Like Flanagan, he enters the 2016 trials at the defending champ and top qualifier.

“With the first marathon, there’s a lot of undiscovered roads there,” said Keflezighi when asked about Rupp. “The first time I did it, I said, ‘I never want to do this again.’ Whether it’s the weather or the distance, the marathon really keeps you humble.”

In addition to Rupp and Keflezighi, Dathan Ritzenhein (2:09:45 qualifying time), Luke Puskedra (2:10:24), Bobby Curtis (2:11:20), Elkanah Kibet (2:11:31), Sam Chelanga (1:02:59, half marathon) and Jared Ward (2:12:56) have been generating buzz around their chances to make the Olympic marathon.

And Massachusetts will be well represented on the course with nine men and nine women, including seven members of the Boston Athletic Association’s running club.

The runners will cover a 2.2-mile loop one time, then repeat a 6-mile loop four times. The 6-mile loop follow long stretches of Figueroa and Flower Streets, and passes landmarks such as the Los Angeles Memorial Coliseum, the USC Campus and Exposition Park. The loop course offers lots of opportunities for fans to see the country’s best marathoners. It also features several sharp turns, including 180-degree turns.

“[The course] excites me,” said Flanagan. “It reminds me of cross-country. I think people will enjoy [the turns], instead of seeing a long stretch out in front of them.”

The race will come down to the runners who can deal well with the heat and the sharp turns and the pressure. And given the weather, it will likely be a slow, cautious start by the top contenders with the final 10 kilometers deciding who goes to Rio.

“It’s a fair system, but it’s a cruel system because you have to be 100 percent,” said Linden. “You have to be ready to go, and then you have to be even better in the next one [at the Olympics]. But I wouldn’t want it any other way.”