It’s the most fun a cyclist can have while gasping for oxygen on burning thighs. It’s Sir Isaac Newton’s Law of Gravity turned on its head. (“What goes down must come up.”) It’s grueling and relentless one minute, delightful and hilarious the next.

Welcome to Passport to Pain, perhaps the only event in the world that kicks off with the question (asked through a bullhorn), “How many idiots do we have with us this morning?” Hundreds of hands shoot proudly into the air, and the tone is set.

“It was positively perfect, and my overriding sense of joy exceeded my fatigue,” said islander Leslie Garrison after last year’s P2P. “The ride was challenging enough but not impossible, with great food and super kind and supportive volunteers.”

This year’s eighth annual ride, created and presented by the Vashon Island Rowing Club, leaves the Jensen Point parking lot at 7:30 a.m. on Saturday, Sept. 8. Each rider chooses among the Idiot, Weasel, Weenie — and new this year, Granny courses. The Idiots will climb 10,000 feet of vertical over a full 80-mile circuit of Vashon and Maury Islands. Every few miles, they’ll roll off the table and down to one of 18 passport-stamping stations, most of which are located at the bottom of Vashon’s gnarliest hills. Once they have their passport stamped, there’s that little matter of then riding back up the hill.

The Weasels (50 miles – 6,500 feet of vertical) ride Vashon but lop off Maury by turning back for the post-ride BBQ once they hit Portage. The Weenies (30 miles – 3,500 feet) essentially ride the southern half of Vashon and call it a day. The Granny is for vintage bikes and takes riders to town and back (11 miles – 800 feet).

“I want to find the people who marked the course and road hazards and hug them,” said a beaming David Kass from Olympia, at last year’s barbecue, “and then I want to find whoever planned the route and punch them.”

Helping push the cyclists along to their next passport checkpoint is the anticipation of what they’ll find there. Besides food and water, P2P volunteers bring creativity, costuming and humor to their cyclist oases. Along the course, a rider might encounter an insane asylum, a tropical paradise or a photo opportunity with the Tour de France as a backdrop.

The theme for this year’s ride is “The Movies,” with everything from Willie Wonka to The Big Lebowski lined up to be depicted.

A number of community groups, such as The Harbor School, Neighborcare Health and Vashon Lacrosse Club, are joining the fun this year by sponsoring checkpoints and receiving a donation from P2P for their efforts.

“It’s $250 for each group this year, and we hope to increase that number in coming years,” said Colby Atwood, a P2P coordinator.

Started in 2011 by a group of Vashon Island Rowing Club’s masters rowers (who also spend a lot of time on their bikes), Passport to Pain has grown each year, both in numbers and reputation. Usually about 60 percent of the riders are first-timers, and 80 percent come from off-island. Early registrations this year are showing an uptick in the number of e-bikes lined up to participate.

One-third of the sponsor revenue from the annual ride goes toward financial aid for VIRC’s junior rowing program. The rest goes toward equipment.

“Rowing is an expensive sport,” said VIRC lead coordinator Zabette Macomber. “P2P helps us provide whatever relief we can offer to the families of our junior rowers.”

Of course, the main topic of conversation at the post-ride barbecue will always be the hills. Vashon has some doozies, such as parking lot hill at the north end (dubbed “The Wall”), the two climbs that branch off at the bottom of Ellisport (lovingly nicknamed “The Evil Twins”), and then there’s Burma Road, a deceptively steep, up-and-down-and-up-again rollercoaster that ends with a celebratory dose of encouragement from the devil himself, played for the sixth straight year by Vashon Chamber of Commerce Executive Director Jim Marsh.

Riders will be delighted to learn that there will be extra porta-potties along the route this year. Also, like last year, off-island cyclists can save themselves a few miles to and from Jensen Point thanks to a shuttle bus and bike transport from the north end (6:30 a.m. and 5:10 p.m.) provided by the Vashon Island School District and John L Scott Real Estate.

Registration for Passport to Pain is $100 until Sept. 1, then $125 for procrastinators. Spots can be reserved at passport2pain.org/register.

— Jeff Hoyt is a member of the Vashon Island Rowing Club.