Why Your Clothing Choices Matter More at Mile 80
When you are 80 miles into a 100-miler and the sun has set, every seam, every pocket, and every ounce of moisture trapped in your fabric starts to matter. The difference between finishing strong and dropping at an aid station often comes down to the apparel you chose weeks earlier. That is why we asked Rendezvu's roster of ultra and trail running experts, from USATF 100-mile champions to coaches with 30+ ultra finishes, which clothing brands they actually trust for the longest days on the trail.
What emerged was not a single winner but a picture of how different brands excel at different jobs. Gorewear dominates layering and weather protection. Janji has quietly become the short and tight of choice for national-caliber ultrarunners. Patagonia's Houdini remains the packable windbreaker that everyone seems to carry. And Darn Tough's lifetime warranty socks keep showing up in race kits from Vermont to the Gobi Desert.
Every product linked in this article takes you to the recommending expert's Rendezvu page, where you can purchase directly and support the athlete whose advice you trust. Below, we break down the standout picks across shorts, jackets, tops, and socks so you can build your own ultra kit with confidence.
Best Shorts for Going Long
Best for Ultra Racing$80–$92
Your shorts need to do a lot of work during an ultra: manage chafing over dozens of hours, carry nutrition without bouncing, dry fast at water crossings, and stay comfortable as conditions shift from blazing heat to cold mountain nights. Two brands stood out across our expert roster for nailing all of these requirements at the ultra level.
Cody Poskin, the reigning USATF 100 mile road champion who ran 13:26 and set a new course record at the Ultra Gobi 400K, is the kind of athlete whose gear choices carry the weight of thousands of competitive miles and the feedback of the runners he coaches. His endorsement of the Janji M's 5" Multi Short is worth paying attention to. He wore them for the entire Ultra Gobi 400K and reported zero chafing during that 64-hour effort. Hunter Macy, who ran the Canyons 100 in them, also includes them in his kit.
On the Gorewear side, Steven Kornhaus brings a different but equally credible perspective. As a UESCA-certified coach who has completed over 30 ultras (including five races of 100 miles or further) and tested 80+ pairs of shoes, his gear recommendations are shaped not only by personal use but by years of advising runners through every distance and condition imaginable. His enthusiasm for the CONCURVE 5" 2in1 Shorts is infectious.
Cody Poskin — From his 'Ultramarathon' list
Hunter Macy — From his 'Canyons 100' list
Steven Kornhaus — From his 'Trail Running Essentials' listJackets and Layers for Mountain Ultras
Best Mid-Layer for Cold Ultras$90
Most 100-mile races require a waterproof shell on your mandatory gear list, and many ultras send you through temperature swings of 40+ degrees from afternoon heat to pre-dawn cold. Your layering system needs to pack small, weigh next to nothing, and still keep you warm and dry when it counts.
Gorewear's CONCURVE line appeared across multiple expert lists for good reason. Steven Kornhaus, whose recommendations are shaped by racing the No Business 100 (where nights can dip into the low 30s with humidity), calls the CONCURVE Thermo Hybrid Jacket a must-have mid-layer. Laurel Walker, a USATF 100k Trail Championships Bronze medalist with podium finishes from 5k to 100 miles, independently recommends the women's version of the same jacket for its versatility as a shoulder-season layering piece. When two ultra specialists with very different racing profiles converge on the same product, it is a strong signal.
For windbreaker duty, the Patagonia Houdini remains the default choice among Rendezvu's experts. Mark Neilan, an endurance athlete who carries it as his go-to windbreaker, and Brady Jonas, a Jackson-based trail runner, both feature it in their kits. Brady's practical advice sums up why: it is lighter than you would expect, and it fits easily in a running vest for those mountain storms.
Steven Kornhaus — From his 'No Business 100' and 'Trail Running Essentials' lists
Laurel Walker — From her 'Trail Running' list (women's version)Steven Kornhaus — From his 'No Business 100' and 'Trail Running Essentials' lists
Mark Neilan — From his 'My Gear' list
Brady Jonas — From his 'Trail Running Kit' listTops Built for All-Day Efforts
Best Sun Protection Top$55
A top that works for a 50K may fall apart (sometimes literally) over the course of a 100-miler. Sun protection, moisture management, and chafe-free seams become non-negotiable when you are running through a second sunrise. Two products stood out from our experts for their performance on the longest days.
Mark Neilan keeps the Rabbit EZ Tee Perf ICE Long-Sleeve in his ultra kit specifically for sun protection that does not trap heat. For runners heading into exposed desert or high-altitude races, that combination of UPF coverage with active cooling is the difference between comfort and heat exhaustion at mile 70.
Steven Kornhaus, meanwhile, has built much of his racing wardrobe around Gorewear's Everyday Tech Tee for its durability when wet. After testing 80+ shoes and more gear than most shops carry, his perspective is shaped by seeing what holds up not just for himself but for the athletes he coaches through ultra distances. When he says a shirt does not stretch when it gets wet, that is coming from someone who has watched hundreds of runners deal with the consequences of fabrics that do.
Mark Neilan — From his 'My Gear' listSteven Kornhaus — From his 'No Business 100' and 'Trail Running Essentials' listsSocks That Survive the Distance
Best Ultra Running Sock$20–$25
Blisters end more 100-milers than any other single issue. The right sock can carry you across a finish line; the wrong one can leave you limping into a drop bag at mile 40. Across Rendezvu's expert roster, Darn Tough emerged as the consensus brand for ultra-distance socks, recommended by three separate experts.
Recommended by 3 Rendezvu experts, Darn Tough's ultralightweight running socks are the clear favorite. Mark Neilan calls them great for all conditions and specifically highlights the brand's lifetime warranty. Spencer Imbach, who won the 2024 Vermont 100 Miler in 17:24, is even more emphatic, calling them the best of the best with no abrasion and the most durable socks you will find. Shelby Farrell, who placed 4th female at the 2025 Cocodona 250, also includes Darn Tough in her trail running kit. When a 250-mile racer, a 100-mile winner, and an experienced ultra athlete all converge on the same sock brand, it is worth paying attention.
For those interested in merino wool options for temperature regulation on extra-long efforts, Spencer also recommends Smartwool's Trail Run Targeted Cushion socks, noting that the material keeps its softness forever. Steven Kornhaus is a dedicated toe-sock runner for 100-milers and swears by merino wool options for the longest races. The principle is the same: invest in your socks and your feet will thank you at mile 90.
Spencer Imbach — From his 'Long Run' listMark Neilan — From his 'My Gear' list
Shelby Farrell — Shelby includes Darn Tough socks across multiple lists
Rendezvu hosts earn a commission when you purchase through their recommendations. Every product featured is one they personally use and stand behind.
