Underun Performance Underwear Review

Support and comfort from start to finish

Recently I was asked to test some Underun products. Now Underun is a dutch based company that is now spreading it’s wings. I’ve tried other rival products in the past and was eager to test these. I picked both briefs and boxers, in two sizes small and medium, as I was on the border between them, sometimes small briefs can be a little restrictive and the last thing you want is for there to be any discomfort in that area when running. Now I know some runners in my current club who are penny pinches when it comes to kit, but for a lot of runners I know decent kit is important. For me I like to have confidence in the products I’m wearing, would they cause issues or discomfort during a race? It’s one reason I don’t wear the club vest, its like running with sandpaper on your upper body.

Product Description(s)
The Underun men’s brief is perfect for the runner who seeks maximum freedom of movement and a free feeling. The brief has flat, soft edges around the leg openings, preventing cutting and chafing in the groin while running.

The Underun men’s boxer is ideal for the runner with firm or muscular thighs. The extra length of the boxer ensures that the upper legs do not rub directly against each other and thus avoid abrasions and irritations.


  • Good ventilation through the breathable zones in this slip
  • Pleasant and fresh feeling during exercise due to the antibacterial effect
  • Ergonomic design that makes carefree movement possible
  • No irritating or abrasive seams thanks to Underun’s seamless design
  • Dry your training dry due to the quick-drying and moisture-wicking fabric for how long you train.
  • 92% polyamide, 8% elastane
  • Washable in the washing machine, provided they are inside out and washed with similar substances. Do not use fabric softener and let it dry without a dryer. The underwear can be damaged in the washing machine by sharper parts such as Velcro and zippers.


So comfort is a must and there is nothing worse than chaffing in the lower regions when you are only half way into your race, get chaffing bad or wear the wrong kit and it’s the difference between a PB and a bad race. I tested both the briefs and boxers over numerous runs of various distances and terrain. With my race shorts having a liner (sort of built in briefs) I found that the briefs were better as the boxers got pulled up to the groin area due to the inner part of my shorts. The briefs fitted comfy and found due to the material and design that a small fitted me lovely and I didn’t find them restrictive. I resorted to wearing my boxers on my long runs with my other shorts that don’t have any built in briefs. Again the small fit lovely but the mediums also fitted but had a bit more give in them. However the difference for me was minor due to me being on the border of small/medium.

Underun offer a range of underwear for both men and women and in a variety of colours, I had no issues with either briefs or boxers but less is better in my view and I had the luxury of both a blue and black version, however I’ve saved the black ones for race day. In all honestly it is one part of my kit I had not really thought about, but if the undies you are wearing don’t keep everything tucked in, then it can make for some uncomfortable miles.

I’ve now worn my briefs in the past 3 races and had no issues. I first tested them the other week on my long 16-miler and within minutes of putting them on they felt great. I found them light and hugged the bits they should making everything comfy from start to finish. What I like is there are no seams or bad stitching that could rub and cause chaffing.The wicking system means the moisture that can cause chaffing never happens, the fast-drying and wicking fabric from  keeps you feeling dry and light.

As I mentioned, I like to have 100% confidence in the gear i’m wearing and the best thing about these is you forget your wearing them, which is a compliment. The briefs have a very impressive wicking system, after a race I’m usually pretty sweaty but the briefs were still pretty dry to touch.

Men’s products retail currently at £18.95, with various colours, visit the new UK website here.

This product was provided by Noisy Communications to review and test. This did not influence the outcome of this review, written after testing since late December.

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