Prior to the start of the 1996/97 season, a 24-year-old Zidane had just joined Juventus and would be put through the most grueling workout of his life.
Led by fitness coach Giampiero Ventrone and his right-hand man Pintus, nicknamed "El Latigo" -- which in Spanish translates as "The Whip" -- Zidane once recalled that he would "often be at the point of vomiting."
Exactly 20 years later, Pintus was lured away from Lyon by Real Madrid and trusted by Zidane to whip his Galacticos into shape ahead of his first preseason as head coach.
Pintus' favored training plans of long distance running clearly had the desired effect, as Real went on to secure a first league and European Cup double for 60 years.
Now in his second pre-season with Los Blancos, the Italian's methods show no sign of abating with Zidane's side already winning both the Spanish and European Super Cups ahead of La Liga's start this weekend. Real start their title defence away at Deportivo La Coruna Sunday.
"We are doing the work that we need to prepare well for the season," midfielder Luka Modric tells CNN while the club were in Los Angeles last month.
"So far we are working really hard, mostly running sessions -- we are doing training sessions with the ball as well. So far we are doing okay.
"It's hard," he says with a wry smile. "But we have to do it to be well prepared for the season."
Since signing for Real Madrid in 2012, Modric hasn't gone a single year without winning a trophy.
Twelve major titles in four trophy-laden seasons -- including the Spanish Super Cup less than 36 hours after his transfer from Tottenham Hotspur -- has seen the Croatian earn the nickname "Lucky Luka."
Modric concedes that preseason training is not a player's favorite part of the sport, but acknowledges it's a necessity if the club wants to continue Zidane's prolific start as head coach.
"For us professionals it's not ... it's part of the job," he says with a degree of hesitancy. "We have to do our best, work hard to do everything the coach is asking from us."
"He set up preseason in that way, he wants us to have a good base for the rest of the season.
"He's very demanding but it's a big pleasure to work with him and he's done an amazing job since he joined Real Madrid. We've won almost everything with him and hopefully we will continue doing well."
If preseason training used to be about preparing players for the physical rigors of the year ahead, these days clubs like Real also use this time in the football calendar to think about their global marketing footprint.
According to Forbes' latest valuation, Real are worth $3.5 billion
. As one of the largest sport organizations in the world and boasting one of the biggest fan bases, the club is naturally interested in connecting with its supporters all across the globe.
Los Blancos have visited the US in 11 of the past 17 seasons and the club's Director of Institutional Relations, Emilio Butragueño, says they are always "delighted" to return.
"This is a fantastic opportunity to build bridges with our fans here in the US," Butragueno, who played for Real between 1984 and 1995, tells CNN.
"We are a Spanish team and we are very proud of that, but at the same time we feel that Real Madrid is universal.
"That is one of the reasons why we try to come back so often, because we want to strengthen our relationship with our fans and share our passion about football."
Butragueño notes the "tremendous" growth of Real Madrid's fan base in recent years, something Modric has noticed when he and his teammates travel to compete on different continents.
Whether it's pre-season in California or the Club World Cup in Japan, replica Real Madrid shirts can be found anywhere the team goes.
"It's really amazing, wherever we go they are there," Modric says. "They are cheering for us, they are supporting us.
"We want to do our best on the pitch to make them happy and to bring success to the club and to them, that we can enjoy and celebrate together for all Real Madrid fans all over the world."