According to Reeves, the most challenging was a car stunt in which his character races around the historic Arc de Triomphe in Paris.
Reeves had to learn how to do a reverse 180 and drift all while reloading his prop gun and shooting it out of the door.
As Reeves explained: "For 'Chapter 4', we wanted to bring the muscle cars back."
"Have we gone too far?" the actor asked about the insane stunts in the film.
"We took the car-driving to the next level, which I really enjoy," Reeves previously told Total Film magazine about the 'Chapter 4' car stunts.
"There's 180s, forward-into-reverse 180s, reverse into-forward 270s, drifting. So it was really fun to get a chance to learn those skills, and to play.
"'John Wick: Chapter 4' has the most action of any of the ('John Wick') films, which is saying a lot. And it's more by a good margin. It's a big show. 'John Wick: Chapter 4' was the hardest physical role I've ever had in my career so far. They really trained me up to be able to have what we call the toolbox," he added.
In 'John Wick: Chapter 4', Reeves' eponymous assassin faces off with new enemies and reunites with old friends on his mission to destroy the villainous High Table once and for all.
Reeves is joined by Bill Skarsgard as Marquis, Donnie Yen as Caine, Laurence Fishburne as Bowery King, Lance Reddick as Charon, Rina Sawayama as Akira, Shamier Anderson as Tracker, Hiroyuki Sanada as Shimazu, Scott Adkins as Killa and Ian McShane as Winston.
'John Wick: Chapter 4' hits theaters on March 24.