"From my side I’ve said it before - this is not sustainable," Verstappen told reporters at the Bahrain International Circuit.
"I love racing a lot and I do it a lot also outside of Formula One.
"But, if people in the sport start shortening their careers because it’s too much I think that’s a shame and so hopefully of course we can have a look at that for the future."
Formula One’s popularity has soared in recent years, driven in part by the success of Netflix show Drive to Survive.
The sport’s commercial rights holders Liberty Media have capitalised by adding new venues in the Middle East, some returning classics in Europe and three races in America, with Miami and Las Vegas joining long-time fixture Austin.
Teams have begun to rotate personnel to cope with the demands of such a long calendar while pre-season testing this year was reduced to just three days.
Spain's double world champion Fernando Alonso (42) a veteran of the sport who made his debut in 2001, echoed Verstappen and recalled the days when the calendar featured less than 20 races.
"When I started we had 16 races, then it was 18 at some point, and then I think when Liberty came it was like a message that we have 20 one season and that was absolutely the limit, 20 races," said the Aston Martin driver.
"And now we are up to 24 and this is not sustainable for the future.
"Even the world champion thinks this is a little bit long, the season.
"Imagine for the rest of us, we go to the races in the second half for nothing, there is no incentive to fight for anything."
