Clothing strategies at the Backyard Ultra World Championships, hit by a 25°C temperature difference and heavy rain
Since October 18, 2025, I have been competing in the Big Dog's Backyard Ultra Individual World Championship held in Bell Buckle, Tennessee, USA.
This race is held in the backyard of Lazareth Lake (commonly known as Laz), who created the "Backyard" running race format, and can be considered the origin of the Backyard Ultra .
The World Championships, held every two years, brings together representative runners from 50 countries and the top 25 record holders to determine the "world's strongest backyard runner."
The race has a unique layout where the course changes between day and night , with the backyard trails running from 7:00 to 18:00 and the road course running from 18:00 to 7:00 the next morning .
The trail in my backyard was a newly constructed single track with lots of ups and downs, requiring high power output to ride. On the other hand, the road section at night was monotonous, and I had to fight against sleepiness. There was no time to rest, and my concentration was constantly being tested.
Lazareth Lake, creator of Backyard Ultra, shouts "HAPPY TIME" and rings the bell to start each hour's race.
Extremely changing weather conditions
Weather fluctuations were a major factor in the 2025 tournament.
- Day 1 (trail): Temperature around 28°C, high humidity and muggy
- Nighttime: Prolonged heavy rain
- Day 2: Trail riding was not possible due to heavy rain → All loops changed to road
- Nighttime: Temperature drops below 5°C
The maximum temperature difference is about 25°C.
In the heavy rain and temperature changes, the choice of clothing and the ability to regulate body temperature determined performance.
The three key wear items I used this time
To prepare for climate change, we used a combination of three things:
I will explain why I chose each one and how I feel about using them.
Axio Lite Tee: Excellent temperature regulation, odor resistance, and quick-drying properties
My first base layer of choice for long distance running races is the wool/polyester blend Axio Lite Tee .
Here are some of the things I found particularly great about Backyard Ultra:
- Temperature regulation adjusts the warmth according to your body temperature. Sweat prevents chills even at night.
- Although it is made of wool , it dries quickly, keeping you dry even when you sweat.
- It has better odor resistance than polyester alone, so you won't feel uncomfortable even when wearing it for long periods of time.
For more information about the Axio Lite Tee, please see the article below.
https://www.teton-bros.com/blogs/column/backyardultra-axiolite
The Axio Lite, used as a base layer, is excellent for use during the day and at night when temperatures fluctuate.
Easy to move in and highly waterproof and breathable | Tsurugi Lite Jacket
- Made with Täsmä material, which is particularly flexible among TETON BROS.'s waterproof products. It doesn't restrict arm movement even in the rain, so you can move your arms freely without any stress.
- Even under prolonged heavy rain, the inside of the garment stays dry and sweat wicks away, maintaining comfort.
- It was a great relief to be able to run to the end without changing my rain and base layers when it rained.
For 100-mile trail races, we use the Feather Rain Jacket , which is easy to put on and take off and can be worn over a backpack.
Even in heavy rain, the water-resistant and breathable Tsurugi Lite Jacket keeps you dry from rain and sweat.
Stay cool even when moving - Combine with other items for increased warmth | Zero-G Fleece Crew
- Active insulation that uses Octa fabric as a mid-layer. Highly breathable, it stays in place even during intense activity.
- Pair it with a weatherproof shell (like the Tsurugi Lite Jacket or Wind River Hoody) for exceptional warmth.
- The brushed back surface has a small contact area with the skin, so sweat does not cool down easily even if it gets slightly wet.
During a rain test before the race, we confirmed that the Zero-G alone was comfortable enough to ride in light rain.
I spent a lot of time running in the versatile Zero-G Fleece, which is made of Octa material that is breathable when worn alone and warm when worn with a shell.
Layering strategies to suit the weather
- Daytime → Axio Lite Tee only
- Cold nights → + Zero-G Fleece Crew
- Rain → ＋ Tsurugi Lite Jacket
- It gets hot while riding → Adjust the ventilation with the Tsurugi angle zipper, and if it's still too hot, take off the Zero-G
I brought a lot of top clothing with me to the US, but these three pieces were pretty much all I needed for the entire race.
Axio Lite, Octa, and Täsmä are high-performance devices on their own, but when combined they can be used in an even wider range of weather and exercise environments.
Layering with Tsurugi Lite Jacket, Zero-G Fleece and AXIO LITE. Ventilation is also used to regulate body temperature.
After the World Championships
The race ended in 54 hours . Although it was a disappointing result as I didn't reach my personal best, it was an invaluable experience to run in Laz's backyard on the same stage as backyard runners from all over the world.
I really want to try again in two years' time at the same place, so that I can race to the best of my ability.
