The Fat Ass began in 2003 with 23 participants who didn't quite know what they had gotten themselves into and who fell in love with running the trails of the Batawa. Over the years the Fat Ass has grown to be one of the biggest trail races in Ontario, and despite the size of it, we maintain the inclusive atmosphere so everyone feels welcome; fast, slow, young, old, runners and walkers. We have various distances, with various start times:
NEW FOR 2026:
Big Bums Kids 1km will start at 1:15pm to avoid congestion on the trails.
NO refunds. We understand that many of our distances sell out quickly and that the life can change a lot between the time you register to race day. However, we can no longer offer refunds, but will extend the date of allowed transfers (October 31st). These transfers must be made between individuals at their own expense.
NO TRANSFERS AFTER OCTOBER 31ST
PLEASE register with the email you wish to receive communication from us about your race details. These are vital details to help your race day run smoothly.
*** FAT ASS SHIRT PRE-ORDER / BADASS SWAG DEADLINE IS OCTOBER 25TH!*** 6 Hour Badasses who register AFTER this date will not receive swag. Fat Ass shirts must be pre-ordered before this date.
50KM Rules/Regulations
There is a hard cutoff time of 5pm.
Runners will be required to have a headlamp after 3pm.
Runners not on their last loop by 3:45pm will not be allowed to finish their last loop.
Pacers allowed on the last loop.
Poles are okay too.
Course Description:
The Fat Ass is a mixed bag of tricks. Rocks, roots, wide trails, single tracks, wooden bridges, creek crossings, hills and meadows. Sometimes snow, often mud, sometimes nothing but sun. Its a guaranteed adventure, brace yourself for anything. Please do not use headphones. If you do, please keep your volume down so you can hear folks who need to pass.
Aid Stations/First-Aid:
There are three aid stations. One on the south loop, one on the north loop and one in between. These are all stocked with water, Tailwind, and a plethora of snacks.
WE ARE A CUPLESS EVENT! Bring your own flasks, speed cups or bladders to refill.
First Aid is provided by Neil Graham of Stat Med Canada
Porta potties will be available at the start/finish line area
Parking:
There is ample parking at Batawa Ski Hill. There is also overflow parking at the Batawa Community Centre. Please do your best to not park on the streets and if you are required to do so not block the driveways of residents.
Awards:
In keeping with the spirit of 'fat ass' style races, and to keep registration costs low, there are NO participant medals.
Medals will only be awarded to the first, second and third place male and female for each distance.
Big Bums (kids 1km race) will all receive participant ribbons.
Swag/Merch:
Various Dirty Soles merchandise will be available for sale.
Fat Ass 2026 race shirts are available for an extra cost (pre-order only).
Bad Ass 6-Hour participants can look forward to exclusive swag included in their entry fee.
FAT ASS SHIRT PRE-ORDER / BAD ASS SWAG DEADLINE IS OCTOBER 25TH! 6 Hour Badasses who register AFTER this date will not receive swag. Fat Ass shirts must be pre-ordered before this date.
Our Sponsors: