Women's: Merino Baselayer

We relied on the Go Athlos Upper Baselayer for most of our Himalayan expedition in spiti valley, and it truly delivered—both as activewear during the day and as a warm layer through the freezing nights in Spiti Valley. I’d highly recommend it to anyone heading into the mountains. It’s incredibly comfortable, offers a full range of movement, and stands up well to rugged use. The fabric keeps you warm in low temperatures, resists dust surprisingly well, and feels built to last. Tried, tested, and trusted

I bought a merino baselayer for a 7 day himalayan trek, and wore the tshirt for first 4 days. It felt light and smooth on the skin, and kept fresh throughout.
Going to buy more for next trek.
Beware though, they run extremely small. I wear a size S in everything, but ordered M after reading another review, and even M is tightly fitting for me.

I wanted to buy the merino base layer before my first himalayan autumn trek, but was not sure if the size would be ok. A few reviews had said the sizes run small, so I followed the advice I got from their customer service - to buy two base layers in two different sizes, and return the one that didn't fit. Normally I buy size M to L. Here, I bought one in XL and another in 2XL, and guess what? I kept both, and wore both, one on top of the other! I am absolutely satisfied with them. Felt light and smooth on the skin. Yet to test them in treks in the south.

I own couple of Merinos from Athlos and have used them for hiking and trekking in the Himalayas
This time i used the full arm baselayer merino for running the Ladakh Marathon!
Performed like the rockstar it is, wicking sweat and keeping me warm before the run started, and dry post the race. Absolutely recommend it!

The fabric is amazing. I purchased two over a course of 2 years. The one I got 2 years back was longer in the torso and the sleeves were not a good fit. The medium fits well in the body but in the armpit it bunches up, the large was too loose and looked frumpy.

But because the fabric is so good, I purchased another one last year because I read similar reviews across the site and figured that the fitting had improved and it had.

The sleeves fit ok now and the torso length was not too long but this time I ordered the butter yellow and sadly it is a bit see through but it's not a problem because I use it as a base layer during winters(I live in the himalayas) and it holds up really well during harsh winters.

I still haven't given up on the fit, the fit could improve, the medium feels too snug and the large a frumpy loose. Contemplating on getting the fennel next, hopefully they've perfected the sizing this time.
I keep coming back for the fabric.