THE city of San Francisco is not going to know what hit it, when 26 of Grafton's strongest bodies swarm the city for the AT&T Park Stadium Sprint Spartan race.
The event hosted at the home of baseball team, San Francisco Giants, will be a big leap for a dedicated Hybrid Fitness team.
The group has eyed off the major Spartan event since the start of the year and gym owner Shaun Davison said excitement has been building as the day got closer.
"We have done a lot of Spartan races across Australia but we wanted to challenge our members and get them out of their comfort zones," he said.
"To get a crew of 26 people has absolutely blown me away. When I put the idea out there, I would have been happy with 10 people but this is close to a quarter of our total members.
"It isn't easy when you are only a small business, and the reason we do get into these things is because we want to see people do well, this kind of support back from our members is amazing."
Davison has worked hand in hand with Grafton Travel Agency to make the process as smooth as possible and he thanked the local agency for their help in planning.
The AT&T Stadium, home of baseball side the San Francisco Giants, challenge has been booked as a tough Spartan race, with athletes to expect plenty of stairs.
Organisers have ensured all athletes are warned that the stadium's course will be no walk in the park.
"America is where the Spartan race was invented so you know they are going to do it right," Davison said.
"I am not exactly sure what we are in for but we know there will be heaps of obstacles that we will have to climb, go through or go around.
"It is a bit of an unknown, but that is half the fun of Spartan races."
The head trainer said his team had been working hard in preparation for the event and would be ready for whatever challenge was thrown their way.
"With the fitness training we do at Hybrid we cover all areas of event, so people are as well prepared as possible," he said. "It's our gym motto, 'walk in prepared, walk out proud'."