Artist Series Biodegradable

W's Runterra Bio Long Sleeve

Odor-resistant + thermoregulating top for daily active wear
$50 $72

60 reviews

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.

Color: Water_Is_Life
Size
Chi-Chi is 5'11" and wears size M Regular fit
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

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.

Backed by our 5-year Guarantee

We make gear that lasts. If your Janji gear doesn't due to any defect in workmanship or material, we promise to repair it, replace it, or give you store credit for it. Learn more about our guarantee.

Artist Series Kits - Janji x Yaikel

Each Janji collection is inspired by a region around the world where we collaborate with local artists. This print is designed by the Santiago-based artist Yaikel for our Chile Collection.

Enhanced biodegradation

Most tees take hundreds of years to decompose. Ours is made from an innovative polyester that breaks down in as few as 4 years in a nitrogen-rich environment (i.e. a landfill, not your closet).

10% for clean water

10% of this sale goes to our water partner, Amulén Foundation, helping them improve water access at rural schools throughout Chile. Learn more.

Customer Reviews

Based on 60 reviews
80%
(48)
13%
(8)
3%
(2)
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L
Linarun26.2
Wear it for: Running, Camping, Everyday wear
Product Fit: Spot-on
Height: 5'0" or shorter
Usual Size: M
Size Purchased: M
Fantastic top!

Great for everyday use, short run only because of the material.

S
Sarah
Wear it for: Running, Hiking, Camping, Climbing, Everyday wear
Product Fit: Runs small
Height: 5'4" to 5'6"
Usual Size: M
Size Purchased: L
My favorite shirt!

I wish Janji would make more of the Runterra long sleeves, because they are my favorite for running, skiing, and every day wear. They're so incredibly soft and comfortable, but most importantly they wash so well! I have both the Cinder and Jasper colors and would buy any other solid colors if they made them.

I have super broad gymnast shoulders and my true size is a M. I size up to a L in these to accommodate my shoulders and love the fit - not clingy at all, and not super form fitting either. Just a great, casual base layer that you can also wear on its own.

M
Maura A.
Wear it for: Running
Product Fit: Spot-on
Height: 5'7" to 5'9"
Usual Size: M
Size Purchased: M
A perfect fall running shirt

Comfortable, rich color, feels high-quality

J
Julie F.
Wear it for: Running, Everyday wear
Product Fit: Runs small
Height: 5'4" to 5'6"
Usual Size: S
Size Purchased: M
Super functional shirt with a fun graphic

I own very few short sleeve running shirts as I tend to go from long sleeves to tanks and back again, depending on weather. I often throw a long sleeve over my tank for my 1st mile, and this shirt is perfect for that as well as any and all of my other running needs. The weight of the material is light and the fabric is soft like cotton, yet it is darn near sweat proof. Love all the colors and graphics on the Janji shirts as makes for a fun run! I found this to run slightly small as I normally wear smalls in all Janji shirts (and XS in Janji running tights), but had to exchange this for a medium. I have a prior release of this shirt style (different year) in a small and it fits great; another difference is that the cuffs on the sleeves and the neck band are wider on the newer version of the shirt than the older one I have. Just for the record, I prefer the old style with the smaller sleeve cuffs & neck band, but that said, I would not have *not* purchased this shirt—it’s a winner and I’m super happy with it and wear it often. Thx Janji!

B
Bonnie H.
Wear it for: Hiking, Camping, Everyday wear
Product Fit: Spot-on
Height: 5'1" to 5'3"
Usual Size: S
Size Purchased: S
Shirts to wear hiking, exercising and casual

Excellent fit, washes well and holds shape.

M
Michelle G.
Wear it for: Running
Product Fit: Spot-on
Height: 5'1" to 5'3"
Usual Size: S
Size Purchased: S
Perfect shirt

Perfect lightweight shirt that still keeps you warm!

L
Lauren S.
Wear it for: Everyday wear
Product Fit: Spot-on
Height: 5'7" to 5'9"
Usual Size: S
Size Purchased: S
Love this shirt

Love it for everyday wear! The material and weight and cut would be great for exercise if you don't mind the color and how much it shows sweat. I would probably wear it for a trail run or hike by myself.

C
C. G.H.
Wear it for: Hiking, Everyday wear
Product Fit: Spot-on
Height: 5'1" to 5'3"
Usual Size: XS
Size Purchased: XS
Confession: I now own seven (I think).

These tops are fantastic. They fit perfectly and are the perfect bottom layer/wear alone top for exercise or casual wear. Not too loose; not too snug. Janji’s colors are flattering and fashionable, so they look good with pretty much everything.

K
KM
Wear it for: Running, Hiking, Camping, Everyday wear
Product Fit: Spot-on
Height: 5'4" to 5'6"
Usual Size: S
Size Purchased: S

Love this shirt

N
Nancy
Wear it for: Running, Hiking, Everyday wear
Product Fit: Spot-on
Height: 5'4" to 5'6"
Usual Size: M
Size Purchased: M
Long sleeve ahirt

It is soft and comfortable!