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W's Mercury Track Pant in Nightshadow

Regular price $88
Unit price  per 

Sustainable materials, responsibly made.

These pants are amazing!
Super clean and fitted, so soft and remind of all the buttery leggings. They didn’t show any sweat and were completely dry after a run. 

— Melissa, Janji Wear Tester
  • Color Nightshadow

    Color Nightshadow

    Color Nightshadow

    Color Nightshadow

    Color Nightshadow

  • Plateau

W's Mercury Track Pant in Nightshadow

Gabby wears size S and is 5'08" Slim tapered fit, Size Chart

Exceptionally soft, the coziness of these track pants is rivaled only by their performance. Made of our Mercury Knit fabric, these 4-way stretch joggers combine lightly peached warmth, moisture-wicking management and dependable protection with secure, roomy pocketing for cold weather running pursuits. Read more

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behind the design

behind the design


Cozy warmth


Peached softness


Introducing the new go-to when the mercury drops. Here's a little background on these joggers: when we set out to redesign our performance track pant, we knew it had to meet some key criteria: 1. total freedom of movement 2. excellent moisture wicking performance and protective warmth without added weight 3. secure carrying capacity 4. a comfortable, streamlined fit. The Mercury Track Pant tackles those handedly. What we didn't know then, and honestly did not intend for was to design a running pant that would feel this cozy, soft and all-around comfy. This pant works hard. This pant does down time hard. This pant challenges the notion of what cold weather running gear should feel like.



Cold weather running comfort
Breathable, moisture-wicking Mercury Knit excels at transferring sweat + heat away from the body for comfort during prolonged efforts

For when the mercury drops
Lightly peached on both sides, Mercury Knit has an exceptionally soft hand feel while providing cozy warmth + thermoregulation without added weight

Snug comfy fit
Minimal, flat elastic waistband with an internal drawcord for a completely smooth, secure fit

Freedom of movement
4-way stretch fabric combined with an inner gusset panel + ergonomic seaming on the outer thigh allow for unrestricted range of motion

Hand warmer pockets
Two zip side pockets can stash gloves, wallet, or nutrition while a bungee loop is integrated into the right side pocket to secure keys

Roomy back zip pocket
A secure back pocket with nylon zipper pull can easily secure most phones sizes (with case) while minimizing bounce in stride

Flat hems
Minimal elastic hem bands allow for easy on/off + keep the pant in place when in motion

Janji signature blue reflective logo on front + “watermark” on back ankle increases visibility in low light 

materials + specs

materials + specs

Mercury Knit
78% nylon, 22% spandex

235g / 8.3oz (W's Small)

Garment made in Vietnam

Fabric Callout

Fabric Callout

Mercury Knit

A 4-way stretch fabric with light peaching on both sides for breathable warmth without added weight, Mercury Knit reinvents how cold weather performance gear should feel — it’s a new level of winter running comfort.

Shop All mercury knit



Mercury Knit is made of premium, durable nylon and is bluesign® 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.

Customer Reviews

Based on 31 reviews
Warm and Wicking

I really love these. I live in FL, so I don’t have to run in truly cold temps. But these have been perfect for our winter here (40s-50s). They are very comfortable, breathe well, and fit nicely. I wish they were a little bit longer and/or the ankle band was a tiny bit bigger but I have pretty long legs (so that might just be a personal problem). I’m 5’9” and 160 lbs. and bought the mediums. They fit me about like a glove or tights, but are not tight, if that makes sense. I could have sized up to a large for a looser, baggier fit, but I have no regrets. Overall, two thumbs up! I got two pair of these - one in each color offered - and am sure to be enjoying them for a long time to come. They are just a joy to run in.


I am in love with these pants for all activities. Hiking? Yes. Running? Yes. Working from home? Yes. Glued to couch? Yes.

Really comfortable!

I received these pants yesterday and took them for a 4 mile run this morning in 44 degree fog. I was pleasantly surprised to find they kept me warm! The cuffs at the bottom are tight, which helps keep cold air out. The fabric is that insanely soft buttery fabric Janji is famous for, and it's incredible. The pants stayed put, no sliding down or riding up. I put my iPhone 12 Pro w/case in the front side pocket and it was fine there, but I think it would've also fit (tightly) in the back waistband pocket. I got a small, which is what I wear in all Janji pants. I'm 5'7", 135ish, and the small fit ok but was a little smaller on me than I expected, and I've seen other reviews since that mention they run small, so I would say I agree with that. The one complaint I have, and it's super minor, is that the color is not what I expected. I got "Nightshadow", which looks like a vibrant dark teal on the website, but in actuality, it's a muted grey-blue. More grey than blue. And definitely not the teal I was expecting. It's not a big deal because I still like the color and the pants are great no matter what color they are. But I would've preferred the more vibrant teal. The pants didn't show much sweat, which was a plus! I would like to see these in other colors!

So soft and comfortable

Hope you make these in more colors! Love the fit and fabric for lounging and cold weather workouts. I think they run small compared to my other Janji bottoms.

Great All Around Pants!

I've used these to lounge around the house, to sleep in, and most recently, during an 18-mile rainy run in 40-degree temps (though I know it can handle far far lower than that!). And you know, it excelled at ALL of those things! They're the softest and most comfy pants I've ever owned, and they look great to boot. The coolest part are the pockets and that they're all zippered, especially the back pocket that can fit my phone. One thing I didn't expect, but really appreciate, are the bottom leg cuffs being snug because they don't allow the cold air to slip through (but they're stretchy enough to get on without any issues). I hope they make this in black, because I'd buy it in a heartbeat :) For reference, I'm 5'1, 110 lbs., and I got the small. Originally I had ordered the XS, which is my usual size, but those fit more like tights. I quickly exchanged them for the Small instead so they'd be a bit looser (like a true track pant, and how they fit the model).