United States' Katie Ledecky cries after winning gold, in the women's 800-meter freestyle medals ceremony, during the swimming competitions at the 2016 Summer Olympics, Friday, Aug. 12, 2016, in Rio de Janeiro, Brazil. (AP Photo/Dmitri Lovetsky) (Dmitri Lovetsky/AP)

The tears rolling down Bruce Gemmell’s face in the wee hours Saturday morning were four years in the making, and you couldn’t possibly understand their genesis if you hadn’t been there for the ride — if you hadn’t seen the daily 5 a.m. workouts and the 70,000 weekly yards of laser-focused training and the countless race-pace sets that left Katie Ledecky on the verge of vomiting one moment, but ready for more the next. She is a Lamborghini, a machine of pure and awe-inspiring power that asks nothing more of its operator than to be pushed to go as fast as it can.

Late Friday night, Gemmell’s lease came up. And two things were understood as he handed over the keys: He will never have another like her, and he was better off for having experienced this.

“What more can you ask for?” Gemmell, Ledecky’s coach since fall 2012, said through stifled sobs. “She’s certainly made me expand what I thought was possible, and my challenge was to figure out what she needed to do to get there.”

She got there, at the 2016 Rio de Janeiro Olympics, with a dominant performance — four golds, one silver, two world records, victories by unheard-of margins of 4.77 and 11.38 seconds — that left grizzled coaches, their fingers permanently curled in the shape of a stopwatch, unable to conjure a precedent. Because one doesn’t exist.

“The best swim that’s ever been done,” Bob Bowman, the U.S. head men’s coach and longtime coach of Michael Phelps, said of Ledecky’s 400-meter freestyle on the second night of the meet.

Ledecky, at 19 the youngest member of the U.S. Olympic swim team, as she was four years ago in London, spent Saturday on a media victory tour — the “Today Show,” the BBC, a news conference at the Olympic media center — and will fly home to Bethesda on Tuesday. A little more than two weeks later, she’ll head to Stanford to begin her freshman year.

“I have to get all my stuff for my dorm,” Ledecky said with a giggly smile. “I’m excited for the next chapter and what the future can hold.”

In 2013, when she and Gemmell sat down after the 2013 world championships to talk about their goals for Rio de Janeiro, they settled on three: a 3:56-something in the 400 free, a sub-8:05 time in the 800 and a victory in the 200. She hit every one, and when the 800 was over, and with it Ledecky’s meet and the daily partnership between athlete and coach, they shared a hug, each sobbing into the other’s shoulder.

“Maybe I would be more guarded with her,” Gemmell said of his tearful private moments with Ledecky on Friday night, “if I could go to work tomorrow morning with her.”

After Gemmell, there were still more hugs for Ledecky to give — to teammates, USA Swimming staff members, other coaches. They have seen her destroy opponents in the pool with an assassin’s cool detachment, and they have seen her goof around in private like the teenager she still is. But no one had ever seen her so emotional.

“I think this is the first time I’ve ever seen her in tears,” Phelps said.

Katie Ledecky developed the "gallop" in her stroke with former coach Yuri Suguiyama. It gives her an advantage in the pool over her female competitors since most do not have the strength to sustain it. (Jayne Orenstein/The Washington Post)
‘I still want more’

Somewhere in that hug line was U.S. women’s assistant coach Greg Meehan, who has been handed the keys to the Lamborghini. The Stanford women’s swim coach recruited Ledecky with a pitch touting the school’s storied and talent-loaded swim program, its Ivy-level academic offerings and its opportunities for even a legendary athlete to blend into campus life.

“She’s probably the most decorated athlete ever to walk onto a campus, in terms of the number of world records, the gold medals, the dominance in her events. It’s unprecedented,” Meehan said. “[But] I think Stanford offers the opportunity for Katie to be herself. It’s the reason Chelsea Clinton and Tiger Woods chose Stanford. Because those people can just come and be part of the climate on campus. I think that climate is going to allow her to have a sense of calm.”

But the unspoken truth is that these next four years, leading to the 2020 Tokyo Olympics, present a series of challenges and potential pitfalls for Ledecky, of the type that have tripped up some who have navigated them before her. There is reason to think she has both the talent and the grounding to survive it, and even to keep improving, but that is never a given.

“I still want more,” Ledecky said Saturday. “I still want to compete at this level. I still want to win the medals. I’m just as motivated as ever, if not more.”

The past four years went by with Ledecky in the protective bubble of her Bethesda home and her parents, Mary Gen and David. She finished high school at Stone Ridge in May 2015 and took a gap year in order to focus on her training. She still lacks five classes, a written test and a driving test before she can acquire her driver’s license; all this time, her parents have been driving her back and forth to practice.

The next four years are less controllable, more given to variables.

“She took the gap year so she didn’t have to go through that transition [in an Olympic year], and now she’s going through the transition — and she’s well prepared for it,” Mary Gen Ledecky said. “It’s not that she couldn’t have done it last year. It’s just that she and Bruce and Greg and everybody were on the same page about the best plan for her.”

The Ledeckys are a family of high achievers, with Harvard and Yale degrees on their shelves, and Katie herself has said turning professional immediately after Rio — to cash in on a massive marketing potential that one agent who represents swimmers estimated could be worth $8 million annually in endorsement income — was never a serious thought.

“I’m only 19,” she said Saturday. “And I only want to represent myself and my coach and my family and my teammates. I don’t think I want to represent anything bigger than that right now.”

But that doesn’t necessarily mean she will stay at Stanford for four years. According to Meehan, in his initial conversations with the Ledecky family, “the family had talked about four years.” Ultimately, though, he said, “She’s earned the right to make that decision.” In reality, the decision will be a year-to-year one. There simply isn’t any reason to decide in 2016 where she will be in 2018 or 2019.

“If she goes to Stanford for four years, fine,” David Ledecky said. “If she decides at some point within the college four years that she wants to go professional, we’d fully support her. We’re not pushing her either way.”

Coaching handoff

The community of elite U.S. swim coaches is remarkably collaborative, and Gemmell could very well find himself involved in Ledecky’s training during her summers and at major international meets such as the 2017 world championships in Budapest. Meehan has shadowed him for much of the past two years, in preparation for this week’s handoff, and Meehan, in turn, considers Gemmell an indispensable resource.

“That’s why it was important for me personally to make sure I had a relationship with Bruce — because I can easily pick up the phone and ask him for advice,” he said.

Gemmell acknowledges his biggest concern for Ledecky’s growth as a swimmer is the fact she will no longer be training with men — something he began doing with her long ago, when it became apparent there were simply no women who could push her in practice — since Stanford’s men’s and women’s programs train separately.

“Greg will figure it out,” Gemmell said. “But that’s a huge — that’s what she’s done. That’s what has challenged her. That’s what has driven her.”

Red-eyed from crying, emotionally drained, Gemmell pondered a question late Friday night: Given the obstacles and the history of swimmers making this transition, how confident was he that Ledecky could still be better four years from now?

“’Be better,’” he repeated. “Does that mean her times are faster? I’m not sure it does. She’s been the most dominant female freestyler ever, probably the most dominant female swimmer ever over four years. ‘Be better.’ Gosh. There can be new challenges, new opportunities. I guess I don’t want to get hung up in the [notion of], ‘Faster is necessarily better, and if it’s not faster, it’s not better.’

“I know that’s how we measure the sport by. But we talk so much about the process, and being better in other ways. I don’t want to set it up as, ‘Gosh, she’s not better because she’s slower than she was two years ago.’ Well, maybe she is better even though the time isn’t faster.”

There has been talk of Ledecky changing up her repertoire, moving down in distance to start dominating the 100 free the way she does the longer ones, or taking on the 400 individual medley. What if she started winning Olympic gold medals in those?

“I don’t think that would be better, either,” Gemmell said. “I guess I have a hard time defining ‘better.’ ”

It was too much to ponder at that late hour, and in that particular emotional state, somewhere between profound satisfaction and profound emptiness.

“I don’t know,” the white-haired coach finally said. “Maybe it’s Greg’s problem.”