Katie Ledecky, right, is all smiles after winning the gold medal in the 800-meter freestyle at the 2012 Londom Olympics. (File photo) (Toni L. Sandys/THE WASHINGTON POST)

For 72 hours here, Katie Ledecky got to see how the other half lives. The half that doesn’t necessarily need to swim 70,000 grueling yards every week in practice to achieve its goals. The half that measures its times in fractions of seconds, not whole ones. The half that doesn’t set or threaten world records every time they jump in a pool — and that sometimes finishes fourth, or 18th.

For one weekend only, Ledecky, the 18-year-old freestyle phenom, got to experience life as a very good sprinter, not the all-time-great distance specialist she has become. Her program for the Arena Pro Swim Series Orlando event, held at the aging but oddly charming YMCA Aquatic Center, featured none of the events she has come to dominate internationally, with world records in each: the 400-, 800- and 1,500-meter freestyles.

Instead, she shortened up and went heavy on the sprints — racing the 50, 100 and 200 freestyles, plus the 200 and 400 individual medleys. It was a curious program, designed not to maximize victories but to break up the monotony of an intense period of training, as Ledecky builds toward what is shaping up to be a historic performance in August’s Rio de Janeiro Olympics.

“I’ve probably had six weeks of the best training I’ve ever had,” said Ledecky, who won five gold medals at last summer’s FINA World Championships, with an unprecedented sweep of the 200, 400, 800 and 1,500 frees. “Just a really good, dedicated period of training. . . . I don’t need to swim [the distance events] in every single meet. It’s good to take one meet off from those.”

Simone Manuel is competing against friend and sometime roommate Katie Ledecky in the sprints this week at the Arena Pro Swim Series in Orlando. Manuel posted the fastest time in Saturday morning’s 100-meter heats. (Alex Menendez/Getty Images)

But the choice of Ledecky’s events this weekend, as selected by her coach, Bruce Gemmell, was also a strategic one.

Ledecky’s standing in the 400 and 800 is virtually unassailable. No woman in the past four years has been within three seconds of her best time in the former, or eight seconds in the latter. The only real question, barring something unforeseen, is whether she will improve her own world records.

By winning the 200 at last year’s Worlds in Kazan, Russia, and then backing it up with a 2016 world’s-best time in Austin this January, she has also established herself as a clear favorite in Rio at that distance as well.

Along with a spot on the 4x200 freestyle relay team — an event in which the U.S. has won gold in four of the past five Summer Games — that gives Ledecky a realistic, though certainly not guaranteed, pathway to four Olympic golds in Rio. Among American women, only Missy Franklin (2012) and Amy Van Dyken (1996) have won that many in a single Olympics.

“She’s really rewriting the rules of the sport,” Franklin said Friday, one day after Ledecky beat her and three other former Olympians in a star-studded 200-free field with a winning time of 1 minute 55.73 seconds, “and to be a part of that, and watching it happen in person, is really a spcial experience.”

The 100 free is where things could get very interesting with Ledecky. As recently as last year, it appeared to be a stretch for her to even enter the event at the U.S. Olympic trials in Omaha this June. Her 2015 best time of 54.55 ranked just 52nd in the world and 10th in the U.S. Then, in January, she swam a 53.75 at the Arena meet in Austin — an eye-opening time that, entering this weekend, stood as the best this season by an American and the fifth best in the world.

But Saturday night, the final of the 100 free here only showed how far she still has to go in the event. Swimming the back end of a 200 IM/100 free double, with only about half an hour in between — the kind of challenge she could face in Rio if she expands her program — Ledecky swam a 54.67 to finish third behind Simone Manuel (54.27) and Allison Schmitt (54.56).

While it is still early in the season, making times and rankings appear misleading, the prospect of Ledecky making a move to the top of the rankings in the 100 free — as her Austin performance two months ago portended — could have huge ramifications for both the makeup of Team USA in Rio and the legacy Ledecky might construct there.

By finishing in the top two in the event at trials, Ledecky would get herself into a fourth individual event at Rio, plus an additional relay, the 4x100 freestyle. And should she assert herself as the top American in the 100 free, it could also get her a spot on the 4x100 medley relay.

But before anyone dreams up a seven-event program for Ledecky in Rio — let alone a seven-medal meet — there are reasons it is unlikely to happen, beginning with the fact that even her best time puts her well outside the range of medal contention at this point. Her personal-best 53.75, for instance, would have put her in sixth place at last summer’s World Championships, nearly a full second shy of a spot on the medal stand and 1.23 seconds shy of gold.

“I’m not targeting a certain medal count this summer,” she said. “I have my goals in the races I’m targeting, and hopefully it will all go well. . . . I’m still learning a lot with the shorter races, even the 200.”

At sprint distances, a margin of one full second is a massive chasm, and despite her immense talent, there simply may not be sufficient time for Ledecky to become a legitimate medal threat — especially because she isn’t willing to focus on the 100 in training at the expense of her core events. If she isn’t a legitimate medal threat in the 100, she probably wouldn’t swim it in Rio.

“It’s hard because of the sacrifice [in training] she would have to make,” said former three-time Olympic gold medalist Rowdy Gaines, now an NBC commentator. “I think the 100, right now, is a throwaway event for her. Could she win a gold medal in Rio at that distance? I would venture to say that would be really hard, against all those great sprinters.”

But a spot on the 4x100 relay — with its potential for a fifth gold medal in Rio, more than any other American female Olympian in history — remains a realistic goal, and Ledecky acknowledged that is her primary motivation in targeting the 100 free the rest of this year.

“I’d love to be on the relay, and if I get on the relay, I want to make an impact. I don’t just want to be another swimmer on the relay. I want to help Team USA out there,” she said. “So I’m going to do everything I can do to get faster than I was in Austin, hopefully a lot faster, and we’ll see where that takes me.”

In the end, Ledecky knows better than anyone else what she is and what she isn’t. On Friday morning, she swam the 50 free in the morning preliminary heats, finished a distant 18th — which would have put her in the “C” final that evening — and eventually scratched.

That afternoon, between sessions, in an otherwise empty pool, when everyone else was napping, eating lunch or otherwise whiling away the day, a lone figure sliced through the water, back and forth, back and forth, with her coach the only person on the pool deck.

It was Gemmell on the deck, and it was Ledecky in the pool, the indefatigable distance swimmer, getting her work in.