The I2 IF Backyard Ultra takes place in Karlstad, Sweden. Runners complete a 6,706-metre loop, with a new start each hour. The format is straightforward: finish the loop within the hour to begin the next; failing to make the start means the race ends. Organized by I 2 IF Karlstad, this event is for runners aiming to see their endurance limits rather than targeting a specific distance.
The loop begins at the I2IF clubhouse near Sandbäckstjärn and enters the former I2 training grounds. The majority of the course follows gravel roads. The primary challenge lies in pacing, nutrition, recovery, and the hourly restart, not in difficult terrain. Participants compete at their own level. This format offers a practical method for individuals to surpass personal distance goals, such as a half marathon or marathon, without pre-committing to a fixed ultra distance.