For most of her life, Molly Huddle had a fairly simple routine before the start of a race.

Huddle, an elite runner, would pack a bag, eat a pre-race meal, do some drills and get to the start line. She knew what she was doing: Huddle is a two-time Olympian and former American record-holder in the 5,000 meters, 10,000 meters and half marathon.

But now, at 39, she has a bit more to think about with a 1 ½-year-old in tow.

“I never thought I’d think about breastfeeding as much as I do now,” said Huddle, who finished third in her New York City Marathon debut in 2016. She will be running it again on Sunday.

She is in good company, and will have a little help.

For the second year in a row, new mothers — two top American elite marathoners among them — will be starting the New York City Marathon with something new speckled along the course: lactation stations.

There will be lactation tents all along the course and a service that allows runners to transport personal nursing pumps from the start area on Staten Island to the finish area in Central Park. Inside the tents, runners will have access to private spaces and hand pumps.

Many Olympians, including Alysia Montaño, Kara Goucher and Allyson Felix, helped draw a wave of attention to maternity issues, resulting in more pregnancy clauses in contracts and more accommodations for runners returning to the top levels of their sport after giving birth.

“Folks know to demand change,” Montaño said. “I do not deserve to be penalized because I’m working into parenthood, or because I’m postpartum.”

Montaño is a co-founder of &Mother, a nonprofit group that focuses on mothers in sports and worked with the New York City Marathon on the lactation stations.

“There have been so many women athletes who have been mothers and have succeeded without our advocacy work,” Montaño said. She added, “It was just 10 times harder for them.”

There is a rich history of runners returning to elite competition after childbirth, but accommodations for new mothers are fairly revolutionary.

In 1960, two years after giving birth to a daughter, the sprinter Wilma Rudolph won three gold medals at the Rome Olympics.

In 2007, Paula Radcliffe, considered one of the marathon greats, won the New York City Marathon about 10 months after giving birth to a daughter. In 2016, Tirunesh Dibaba of Ethiopia placed third in the 10,000 meters at the Rio Olympics, earning her sixth Olympic medal a year and a half after giving birth to her son.

“You can do it,” said Kellyn Taylor, an American marathoner. “You can come back stronger. It’s been proven.”

She would know.

Thirteen years ago, Taylor, who is 37 now, gave birth to her eldest daughter, Kylyn, then returned to her track career only to find herself “pumping in an open field.”

“There was nowhere else to do it,” she said, laughing. “It is what it is.”

On Sunday, Taylor is once again returning to elite running after the birth of a child, this time 10-month-old Keagan. Taylor and her husband, Kyle, have also fostered many young children and in the past year adopted two children, Kaisley and Koen.

(For those wondering, Taylor said she does not nap.)

Taylor and Huddle will be joined by a gaggle of marathoning mothers — the Kenyans Hellen Obiri, Peres Jepchirchir and Brigid Kosgei among them — who are poised to battle for podium spots.

It’s a stacked field. Obiri won the Boston Marathon this spring with a time of 2 hours 21 minutes 38 seconds. Kosgei broke Radcliffe’s longstanding marathon world record in 2019, running the Chicago Marathon in 2:14:04. (The record has been broken again since.) Jepchirchir won the marathon gold medal at the Tokyo Olympics in 2021 and the New York City Marathon a few months later.

Family planning has long been a contentious topic for athletes, whose body is their business. To some extent, peak childbearing years and peak distance-running years overlap, so accounting for both is a continuing calculation, Huddle said.

She and Taylor are racing on Sunday as a precursor to the U.S. Olympic Trials for the marathon, which are scheduled for February. The timing is quite calculated.

Huddle contacted athletes who had already had children and asked for guidance. Some had a quick turnaround. The marathoner Aliphine Tuliamuk had a baby in January 2021 and a ticket to the Olympics that August.

Some trained through pregnancy, while others took an extended time off. Everyone Huddle spoke to had a different experience returning to competition, and when she looked to advice from the medical community, she didn’t find guidance fit for an elite athlete.

“Is it a one size fits all? No,” said Dr. Abigail Campbell, the director of N.Y.U. Langone’s Center for Women’s Sports Medicine.

She said that more of her patients were tuning into their bodies and finding what worked for them. That can depend on how their delivery was, whether they were having pelvic floor issues and how their bodies responded to hormonal changes.

It wasn’t all smooth sailing back to competition for Huddle. She had a femoral stress fracture in March, which she believes might have been caused partly by failing to get enough nutrition while breastfeeding. She has since adjusted her diet.

It’s all part of the process, she said. Her 1 ½-year-old, Josephine, will be on the sidelines Sunday to cheer her on. Josephine has taken to imitating her mother doing drills.

Before the sun rises on Sunday, Huddle and Taylor will both begin a new kind of race morning routine.

There will be a pre-race meal and a pre-race pump. They aren’t sure when exactly they will do it, but they are happy to have options.

“If you want women to get back out and thrive in their careers, in the world, these spaces need to be available, not just in running but everywhere,” Huddle said.