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The wait for first chair sometimes makes you shiver, but when it threatens to dangerously lower your body temperature, slip on the heavyweight Under Armour Base 4.0 Bottom. It's Under Armour's warmest baselayer pant for the days that separate the care-free skiers from wussy hot-cocoa drinkers.

  • Heavyweight, four-way stretch polyester and elastane fabric maximizes heat retention, breathes away moisture, and dries quickly if you take a hike in the afternoon
  • Flatlock seams and ergonomically placed seams let you move naturally while skiing or boarding without chafing
  • Elastic waistband secures the boxer as you get gnarly on or off the hill
  • Working fly simplifies pee breaks
  • Armour Block anti-odor technology in the fabric inhibits the growth of odor-causing microbes

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Here's what others have to say...


Fits Small

  • Familiarity:I've used it several times
  • Fit:Runs small

I love these base layers for very cold days, but they fit very small, the large says [34 - 36in waist] ... I am a 32-33 inch waist depending on the pants (bought large so that they would fit somewhat loose) ... and the large is too tight

Same problem. I'm a 31-32 waist and normally I get mediums (sometimes small), but these were way too tight for me in medium. Exchanged them for a large.

Same problem here too. I got stuck with a medium missed the return date by days. I need a large


Thick and burly

  • Familiarity:I've used it once or twice and have initial impressions
  • Fit:True to size

I have used mid-weight legging similar to the UA 2.0 before but I entered a new world when I tried out the UA4.0 recently. These heavyweight bottoms are not ideal for activities as heat-producing as trail running, but they will keep every bit of your lower body warm during other activities where your body needs a little extra help. Still maintaining a low fitted profile and the elastic feel of thinner tights, the 4.0 will not drop the ball when you are buried in spindrift.