Backyard Ultra races are a unique form of ultramarathons that test both the physical endurance and mental resilience of runners. The concept is simple yet extremely demanding: every hour, participants must complete a circular course measuring exactly 6.706 meters (4.167 miles). If they finish the course in less than an hour, the remaining time is theirs to rest, refuel, or prepare for the next lap. However, anyone who fails to complete the lap within the allotted time is eliminated.

The race continues in this manner until only one runner remains on the track. This final athlete, who manages to complete the lap alone, is declared the winner. The philosophy of Backyard Ultra is not focused on speed but on consistency and repetition. Runners are challenged to find their ideal pace, manage their energy, and maintain regularity in refueling and resting.

In Greece, races like the Kefalonia Backyard Ultra and the Cretan Backyard Ultra have embraced this unique challenge. They offer runners not only a demanding physical and mental test but also the opportunity to push their limits while enjoying Greek hospitality and breathtaking landscapes.