It might be the unlikeliest instructional video ever, but footage of two Japanese amusement park executives demonstrating how to "scream inside your heart" to avoid spreading COVID-19 while on a rollercoaster has been a roaring success.

"Now our customers stay silent while riding on rollercoasters," a spokeswoman for amusement park operator Fujikyuko told AFP, after the video on riding etiquette for the coronavirus era went viral. The video features the executives, one in a full suit and tie, the other in a shirt and bowtie, sitting stiffbacked and straightfaced in silence, with only the only sounds coming from the whipping of the wind and the grinding of the rollercoaster.

As they plunge downwards, one executive serenely readjusts his hair, and his facemask, but both otherwise remain stoically silent, even as they sway violently in the coaster car. At the end of the ride, one man lifts his hands off the seat handles, visibly trembling. A black screen follows featuring advice that some social media users have dubbed a slogan for 2020: "scream inside your heart."

The video was first posted last month, as coronavirus restrictions eased and reopening theme parks asked visitors to avoid screaming and keep social distance. "Even though the amusement park association's guidelines ask you to 'refrain from speaking loudly' we have received complaints it is 'difficult' or 'impossible', so Fujikyu Highland offers a good example," the operator said on its website with the video.

It promised customers who could keep their screams silent would get a discount on photos taken of them on the park's signature Fujiyama coaster, which plunges riders from a height of more than 71 metres.

On Twitter, the footage delighted viewers in Japan and around the world. "This video is great fun," one Japanese user wrote. Others lauded the theme park for inadvertently summarising the way many have felt after months of the coronavirus pandemic. "Literally the best description of 2020 I've ever read: please scream inside your heart," one Twitter user wrote.