In the beginning of summer I became a brand ambassador for Woolpro, I got to test two of their new products and share my opinion on them. The first one is the Juno lightweight baselayer merino t-shirt.

Kapabashi bridge after Tokuga Toge runKapabashi bridge after Tokuga Toge run

Method of testing

At the start of June me and the family moved to Japan for extended stay and a trip. Goal was to see the country, learn language, hike, climb and have a good time. My testing involved three different uses of this baselayer. Daily running, trail running in the mountains and hiking/climbing in the mountains.

Daily Run

I ran in Juno usually in the morning, usually from 6 to 10 km, with elevation gain and drop of a 100meter or so. Temperature and humidity varied, from nice and cool to blistering hot and sauna level humid. On a few occasions I used a windbreaker shell to stop wind and rain.


Juno is really the best Merino layer I used for running, things I tried before were just too warm. The fit was excellent and in general it performed great. However there is a reason synthetics exist, in the really brutal hot and humid conditions when your body is pumping out sweat to try and keep itself from overheating, good synthetic can transfer moisture faster. Merino tends to get saturated with sweat and this leads to chafing on the skin.

Except in very humid and hot conditions Juno is great for runnning. The t-shirt feels comfortable to the skin, resilient(no damage to far at all). Is light and does not stink! However when running in very humid conditions I would still pick a synthetic. Since I have about half a dozen different tshirts for running I basically use Juno all the time except when it is very hot and humid.

Trail running

I ran few trails in Juno the longest being a classic way into Kamikochi Valley, the Tokuga Toge pass. Running this trail I got lost and wondered up some abandoned trail to nowhere, scrambling up river, bushwhacking etc. Biggest difference in this application is that in the mountain the air is cooler and you often wear shell to protect against wind. In my case I started out with a shell and is it got warmer I removed it and went with only Juno and running shorts. The full length of the trail and my detour was 30km. Strava Showed 2.8km elevation gain(bu I suspect it was less).

On my way back I took a bus still wearing Juno, I am sure people sitting close by were happy it was not a synthetic!


Absolutely no complaints worked great as a short sleeve t-shirt. However in the future I will probably get a long sleeve version of it. Few reasons. Japanese mountains are full of plants with nasty thorns, when bushwhacking this is a big issue. My forearms looked like I got into a fight with a cat. When wearing shell you really need coverage so that sweat is transferred off the skin. Lastly when running for a long distance the sunscreen washes out from tons of sweat and as you get higher up the UV is quite strong.

Great trail running top, but the long sleeve version would probably be somewhat better. When descending and running fast it is probably better though, wind felt nice on the arms.

Mountain hiking and climbing

Top of the Gendarme on the Shin Hotaka ridgeTop of the Gendarme on the Shin Hotaka ridge
Later in the day worst is behind usLater in the day worst is behind us

I did a few trip using both Juno and Helios(separate review). Hiked Shirouma through the Daisekke route, Training hikes on Takabochi and long hard(for me!) traverse of Oku Hotaka to Shin Hotaka(known here as the Gendarme route).

Except Hotaka I was wearing a Windstopper shell, on Hotaka I switched to a Patagonia softshell. Hotaka traverse, had a first day approach with gaining about 1.6km and lasting about 9 hours. Then an 11 hour traverse and heading back down to get on a bus out. Traverse itself is a lot of scrambling up and down loose rock, the really hard section where rope would be necessary are equipped with chains. When it was colder I was layering Juno with Helios hoodie on top of it. As I was warming up and cooking in the morning I was also wearing artificial insulation jacket under the shell.


First day famous 5/6 col of Maehotaka behind me, still few hundered meters of ascent to the Hotaka ridge lineFirst day famous 5/6 col of Maehotaka behind me, still few hundered meters of ascent to the Hotaka ridge line

Probably the best use of Juno. Together with Helios you get good control of warmth. You are not running and it is cooler so Merino can deal with sweat quite well. Juno feel great when climbing(meaning you don’t feel you are wearing it at all).


Juno is an excellent baselayer. The only situation where I feel synthetics are better are when running in hot and humid weather. For layering alone under a shell it is probably best to get a long sleeve version of Juno, Skylark.

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Dmytro Yashkir

Canadian programmer living in Japan, climber of mountains, coder of things, student of languages, conoseur of Beer and Nihonshu

Nodejs, Postgres, Ruby, Redis, Swift

Shiojiri, Nagano, Japan