Afternoon prayers have ended in an Istanbul mosque and the silver-haired men turn their gaze from the imam to the sports instructor in a white polo shirt.
A dozen worshippers and the imam with a long, carefully trimmed beard stand up straight, feet planted on the thick, turquoise carpet of the Abdulhamid Han Mosque.
Then they raise their knees, rotate shoulders and hop in place, exchanging muted giggles and shy glances.
For 15 minutes they followed the instructors' movements, getting more exercise than they had done in many years.
"A person is like a vehicle. Just like we need vehicle maintenance, when we do sport our organs improve," mosque-goer Servet Arıcı explained.
Like the others, the 66-year-old had been doing his daily gymnastics since January, when a fitness project was rolled out in 11 mosques of Istanbul's Bağcılar district, one of the massive city's most densely populated.
To his right, the veteran of the group, Hüseyin Kaya, 75, said he was delighted to "make every part of my body move."
"It makes a difference," the bearded former taxi driver said, his forehead creased with wrinkles under his black skullcap.
The instructor, Fatih Yamanoğlu, said the daily routine was enough "to avoid future injuries and make life easier" for the elderly men.
Between 25 and 35 worshippers work on their flexibility every day after the noon and late afternoon prayers, Yamanoğlu said.
In a country where the share of the over-65s has almost doubled in 25 years to more than 10%, offering workout sessions in mosques "might be a good idea." Serap Inal, director of the Department of Physiotherapy and Rehabilitation at Istanbul Galata University.
"However, I would suggest taking them out and exercising in fresh air," she said.
The imam, Bülent Çınar, is delighted his mosque is now more than a place of worship, attracting fitness-conscious faithful from neighboring mosques.
He said he was also ready to have "a female instructor" lead exercises in the women's prayer room, urging the initiative to be extended across Türkiye's 90,000 mosques.
"After we do these exercises, the quality of their prayers improves," the imam said.
"They move more easily. They are rejuvenated."