Endurance Shorts
Model Karim (black) is 5’11” tall and wears size M
Free Goodie
Free Performance Cap
from CHF 150 order value
Free Crew Beanie
from CHF 200 order value
Complete your look
Product Information
The Endurance Shorts combine a supportive inner layer with a breathable, ultra-light outer shell – delivering stability, comfort, and full freedom of movement at any pace.
The dual-layer construction prevents chafing and stays reliably in place, even on long-distance runs.
Four strategically placed pockets offer secure storage for keys, gels, or your phone – without getting in the way.
Reflective details ensure visibility during early mornings or late sessions.
Performance you can count on – wherever the run takes you.
Material and Care
Outer material
85% Nylon
15% Spandex
Inner material
77% Nylon
23% Spandex
Care instructions
Machine wash cold
Wash with similar colors
Do not bleach
Do not use fabric softener
Do not tumble dry
Iron at low temperature
Shipping & Returns
Shipping:
We work with top-tier shipping partners worldwide to ensure fast and secure
delivery.
Shipping costs are calculated at checkout.
– Shipping to Germany is free for orders over €150.
– Shipping to Austria and Switzerland is free for orders over €200.
– Shipping to other European countries is free for orders over €300.
– Shipping to non-European countries is free for orders over €350.
Returns:
You can return your items within 14 days of receiving your order.
Return shipping costs €4.99 and will be deducted from your refund.
Returns can easily be registered through our returns and tracking portal:
Free Goodie
Free Performance Cap
from CHF 150 order value
Free Crew Beanie
from CHF 200 order value
day one is not just a brand — it’s a mindset.
Built on belief and obsession, we design high performance apparel for those who live by the same
code — those who choose to show up, no matter what.
Every piece is forged in the real world: tested under the harshest conditions — from ultramarathons to relentless hours in the gym.
Our design language is clean, minimal, and functional — with every cut, seam, and fabric choice serving a purpose. No distractions. No unnecessary details. Just timeless silhouettes engineered to move with you, feel premium on skin, and perform under pressure.
We use only the highest-grade materials, selected for durability, comfort, and precision fit. From the stitching to the packaging, every detail is refined to meet the highest standards.
Built for Performance
Premium Quality Fabrics.
Engineered for Movement & Endurance.
Battle-Tested by Professional Athletes.
Timeless design. Maximum purpose.
Discipline. Vision. Obsession.
May our day one performance attire serve as a call — to embrace every challenge you face, and to push your boundaries to a new level.
We, as founders, live and breathe what day one stands for. To show what the human body and mind are capable of, Arda took on the hardest challenge of his life: running a 3,000 km ultramarathon from Berlin to New York. And now — he’s doing it again. Running another 3,000 km through Japan. 1.5 to 2 marathons every single day.
Why? To embrace new limits. To show what’s possible. And to battle test the collection we’re sharing with
you.
We didn’t just design this collection. We forged it. Kilometer by kilometer. Gym session by gym session.
Every single piece has been pushed to the edge — under the most brutal conditions imaginable.
So when it lands on your doorstep — when you unpack it, wear it, move in it —you know it’s real.
Complete your look
Discover more
day one is a mindset.
Built on conviction and obsession, we create performance wear for those who show up every day, no matter what.
Every piece is tested in real-world conditions, from 3,000 km ultraruns to endless hours in the gym.
Our design is clean, minimalist and functional. Every cut, every seam and every material serves a purpose. No distractions, just timeless silhouettes that move with you.
We use only premium materials for exceptional durability, comfort and a precise fit, with attention to every detail, from stitching to packaging.
Discipline. Vision. Obsession.
May our day one performance wear inspire you to embrace every challenge and redefine your limits.
As founders, we live what day one stands for. Arda ran 3,000 kilometres from Berlin to New York, followed by another 3,000 kilometres across Japan, running 1.5 to 2 marathons every day. This year, he took on Death Valley: 604 kilometres in 123 hours, through desert and heat.
Our pieces weren’t simply designed. They were forged. Kilometre by kilometre, workout by workout, under the most extreme conditions.
When you wear them, you feel what day one stands for.