The Runterra Bio top seamlessly blends style with sustainability, featuring a soft, cotton-like feel enriched with 37.5® polyester for superior moisture management. This innovative shirt biodegrades in anaerobic conditions, ensuring a minimal environmental impact while delivering odor and thermal regulation for active lifestyles. Its versatile design is perfect for daily runs or spontaneous adventures, establishing a thoughtful choice in activewear that emphasizes both performance and eco-friendliness.
From the brand: Top Description
Run in it, sweat in it, live in it — then biodegrade it!
The first synthetic-blend running shirt that biodegrades like a 100% cotton tee, our Runterra Bio offers the enhanced moisture and odor control of specially-formulated 37.5® polyester with the comfort and versatility of cotton. This new, innovative fabric breaks down into organic compounds in under four years. Conventional polyester takes four
hundred
.
Don’t sweat it
— this tee will only start to biodegrade in anaerobic (oxygen-poor) environments. It breaks down in the landfill, not in your closet.
Read more
Sizing
Gabby wears size S and is 5'08"
Abigail is 5'7" and wears size S
Chi-chi is 5'11" and wears size M
Talia is 5'8" and wears size L
Regular fit,
Size Chart
Cards
behind the design
This is not your typical shirt. Runterra is a blend of US-grown, long-staple Supima® cotton — which is stronger and softer than typical cotton — with a special polyester that has been blasted with volcanic particles to enhance odor-resistance, speed up dry time and provide greater thermoregulation. Yes, it has volcanic particles in it and no, you will not feel them. The fabric is incredibly soft, comfortable and durable yet lightweight, and is intended to be worn repeatedly between washes to reduce water use.
features
Biodegradable
Runterra Bio is powered by a specially formulated 37.5® polyester with enhanced biodegradation to break down into bio-based compounds in under 4 years in an oxygen-poor environment like a landfill
Premium cotton
Made from long staple, US-grown Supima® cotton for superior softness, strength + durability
Active comfort
37.5® polyester with embedded volcanic ash provides enhanced heat + moisture regulation as well as odor-resistance
New sport raglan
Signature raglan sleeve design keeps seams off the top of the shoulders for comfort
Hang it up
An elastic locker loop is integrated into the back neck tape
materials + specs
Runterra
70% Supima® cotton, 30% 37.5® tech polyester
Garment made in Vietnam
care instructions
fabric
runterra
sustainability
Why do biodegradable synthetics matter?
While we design Janji gear to last and hold up to the demand of years of running, no tee or running shorts should last forever. With this in mind, we are researching innovative ways to improve end-of-life cycle management of our apparel. While we look into longer-term solutions and circular methods — recycle, repurpose and reuse programs — we also know that most textiles are thrown out and end up in landfills. Conventional synthetics, used heavily in active apparel for their high-performance functionality, do not biodegrade in typical landfill conditions. This includes synthetics made from recycled materials, and is why most plastic seemingly lasts forever.
We are seeking solutions to fix this as a performance apparel company that relies on synthetics, including the use of non-ecotoxic biodegradability within our textiles like this new Runterra Bio. This is the first step on a better path forward.
Runterra is made from premium, long-staple Supima® cotton which is 50% longer and up to 45% stronger than other cottons (and softer, too). The stronger the fiber, the more durable the garment, and therefore the more it can be worn. Supima® cotton is grown by a select few family farms that utilize advanced water and soil management techniques to reduce consumption and ensure the health of the land for optimal renewability.
Runterra fabric is also OEKO-TEX® certified, meaning it is free from harmful chemicals and is fabricated in a way that meets a high environmental standard.
Learn more about our sustainable initiatives
here
.
Highlights CP
Title: Runterra Bio Tops
Header: Everyday activewear + style
Description: Cottony-soft feel, odor + thermal regulation, enhanced biodegradation
Best for: daily runs, spontaneous adventures
Fit: regular
Designed for: 45~85+
Shop the: Tee
