The haj is no longer an old person's ritual as a new generation of youthful Muslim pilgrims has transformed both the annual rites and Mecca itself.
"The younger you are, the easier it is," says Saniah, a British pilgrim who, at 25, was on her second trip to Islam's holiest site in Saudi Arabia.
"Twelve years ago my family and I came for umrah," the lesser pilgrimage which can be performed throughout the year, she says, elegantly veiled in green and black.
This year, Saniah returned for the haj because it is a religious obligation and "a radical change of life", said the Briton, preferring not to give her last name.
Saniah is among roughly 1.5 million people from across the world attending the haj which formally began on Saturday.
The haj is one of the five pillars of Islam, which capable Muslims must perform at least once, marking the spiritual peak of their lives.
A can of soft drink in one hand and a cone of French fries in the other, Saniah eats with her husband at one of the many modern commercial centres dotted around the Grand Mosque in Mecca after performing Friday prayers.
"In early generations young people waited to be old before doing the pilgrimage," Saniah says.
"But the new generations, we're more aware of our religious obligations."
Smiling, she adds that the long haj marches and prayers under a burning sun "are easier to bear when you're young".
Omar Saghi, author of "Paris-Mecca, Sociology of the Pilgrimage", says the haj is no longer "the mystical horizon of an entire life but a rational event" which has become almost routine.
Mohammed, 33, who travelled to the haj with his wife from Paris, says a number of their friends have already performed the haj.
Their travel agency told them it is also sending many other young couples.
"The haj is one of the five pillars of Islam," says Mohammed, a physical education teacher.
"It's an obligation and so, as soon as we had the means and while we're healthy, we decided to do it," he says, waiting in line at a luminous fast food counter with his wife Madiha, 28, a student of education science.
"Rather than buy material things like a car, better to spend our money on something that is going to benefit us on a spiritual level," she says.
Mohamed Khazma, who works on the security team at a hospital in Tripoli, Libya, is searching for a table to eat his fried chicken.
At 27, he says he is delighted he was able to gather enough money to come to Mecca, because "it's an opportunity that not everybody has".
The rising number of such young people, "more educated and already used to tourism and mass consumption", has slowly helped to change the face of Mecca, the author Saghi says.
"The big (advertising) signs, the big companies, capture this new clientele that the classical market of hotels and family restaurants can't satisfy," he says.
Saniah recalls that, during her first visit to Mecca 12 years ago, they ate in the street.
"It's a lot better (now). We have the option of five-star service."
Khazma, however, wants nothing to do with the shopping centres, their air conditioning, restaurants and shops.
"I forget all of that," says the young man with a short trimmed beard and long grey jalabiya robe.
"I take my Koran, some dates and some water and I stay in the Grand Mosque from afternoon until the middle of the night," says Khazma.
Mohammed also says he is sometimes uncomfortable with all the modern conveniences which are "very far from the time of Abraham and the harshness of the desert" thousands of years ago.
He says he and his wife were obliged to accept their travel agent's plan and hotel to perform the pilgrimage in the footsteps, they believe, of the Prophet Mohammed and Abraham before him.
"But we often wonder if all of that is in line with our spiritual quest," Mohammed says.
"The shops, the luxury, the commercial centres, it clouds the spiritual