In 2014, Mr. Sisi and the military unveiled an ambitious makeover of the Gezira Youth Center, which had been little more than a huge, weedy public lot next to the upscale Gezira Sporting Club in Zamalek, the island in the Nile that is home to many embassies and villas.

President Gamal Abdel Nasser seized the center from the Gezira Club in the 1960s to give Egypt’s young people something comparable to the country’s opulent private country clubs, but it had long been neglected. Even two years ago, a jogger could barely find the running path — a horse track dating from colonial times.

Now that track has been repaved with spongy asphalt and expanded to be wide enough for six runners, and it circles a complex with facilities for beach volleyball, tennis, swimming, basketball, wrestling and gymnastics — all open to the public for a little more than $1 and often overcrowded.

The demand for workout space is so high that dozens of young people join impromptu calisthenics classes in the evenings on a dusty building site adjoining the center.

Traditionally, Professor Fishere noted, authoritarian governments have been interested in promoting sports and physical culture. And in this case, it was a relief valve on the pressure cooker that is the Arab street.

“This is a safe area for both, an area the regime is willing to support,” Professor Fishere said. “And for the youth, it’s a good outlet for their energies.”

That is particularly important in a society where 62 percent of the population is 29 or younger, according to government statistics.

Back in 2014, a jogger along the Nile River would have had the broken sidewalks and potholed roads to himself; these days they are often crowded by 7 a.m. Cairo Runners, founded soon after the revolution in 2011, fields thousands of joggers every Friday, and thousands more join bicycle rides on the weekends — despite the city’s notoriously dangerous traffic and even in the searing August heat.

When Nirvana Zaher, an Egyptian fitness trainer and consultant, ran a Gold’s Gym franchise in Cairo in 2008, it was practically the only scene in town for fitness fanatics. The revolution changed that, she said, and not just because young people gave up and turned from politics to sports.

“A lot of Egyptians didn’t realize their true nature before the revolution, didn’t realize we could do things we’d never imagine,” Ms. Zaher said. “The revolution was just a catalyst. Even as the political revolution has ended, internally the revolution has never ended.”

Not everyone agrees that the failure of the political revolution spawned the one in fitness.

The Egyptian Rowing Club, one of many with boathouses on the Nile, is so busy that there is often a waiting list for the club’s sculls and kayaks. Even so, Abeer Aly, a board member, says she thinks the increased popularity is just a sign of the times worldwide. “I can’t see the correlation between youth revolution and fitness events,” she said. “I just see a trend of people practicing and enjoying rowing, cycling and other things a lot more.”

But Ibrahim Safwat, 31, who founded Cairo Runners in 2012, said the uprisings gave people permission to occupy public space in a new way, whether it was for politics or to have fun. “After the revolution people felt the streets are ours, we can do whatever we want on the streets,” he said. “This gives us hope, and people feel they have a little power.”

Cairo Runners is one example that has made the authorities nervous. Each Friday, as many as 8,000 runners pour into the streets, and often the organization has trouble getting permits for its runs. But crowds come anyway, and there are so many people that no one dares to stop them. Mr. Safwat has no trouble summoning up hundreds of volunteer marshals to control the crowds — many of them veterans of the 2011 protests, in which they had similar roles.

In a working-class neighborhood of Giza, Omar Khalid el-Gabaly, 21, took up street workouts with a group of friends, building bars and poles in an abandoned building and inventing moves that sometimes look like a cross between gymnastics and jumping jacks. The sport is now affiliated with an international calisthenics federation, and his club is called the Bar Pharoahs; other street workout clubs have opened in 14 provinces across Egypt.

“After the revolution, everyone had a power in them, they saw that,” Mr. Gabaly said. “They had to hang that up, but if politics is out, young people aren’t happy about it and they need something else.”