Inside and outside are two VERY different scenarios. Even with my proper cooling (3 fans well placed) inside with a base layer on is warmer, if that is the only variable changed.
Not all base layers are the same. Most list an applicable range of temps or a typical use. Some are great for cold, cool up to hot. They can be terrible for anything outside their intended range. So, I highly recommend being specific about the base layer in use and make sure it is an appropriate one for the conditions.
I have used a base layer INSIDE, with great success. The difference is using the base layer in addition to direct cool water applied to the base.
I have a very open, mesh type base, and drip on cold water from a bottle, before intervals. I get an immediate cooling feel from the cold water that is super refreshing. I apply to my shoulders, upper chest, and entire back.
Those areas also happen to be the ones in direct air flow from my fans, so after the ācoldā wears off, I am getting evaporation cooling from those areas.
I apply this when I am unable to get cold air from my usual outside window, and I want more cooling than the pure room temp and fan air flow.
I have 3 different ranges of base layers, and use them within their intended purpose. At the hottest end of the spectrum, I donāt bother with a base. I focus on choosing a well vented and good material jersey that is meant for the hotter conditions.
As with anything in our world, there are MANY options, and few are the best to use at all ends of the spectrum. Base layers are not different, should be used as intended or not used at all, when appropriate.
All good points. I found my summer base layer to be hotter in both situations (in and out) but more problematic inside. I donāt think I will wear mine outside if it gets above 80 ish similar to what @Power13 mentions above. Maybe even slightly cooler. I have some SPF sleeves that I wear up to 100 degrees and they always seem cooler than no sleeves. I guess to me it seems like the double layer is problematic.
One unintended benefit I suppose is wearing a summer base layer indoors might help with heat acclimation if that is an adaptation you are after.
Anecdotally hotter with a base layer. Iāve worn a number of different types and brandsā¦ Nothing feels cool to me.
I wear them in cooler temps all the time under regular jerseys and under thermals.
I wear a sleeveless base layer on the trainer 100% of the time. I find theyre pretty great for this. Better than a jersey.
It just doesnāt make sense to me with a decent jersey. If the jersey is designed to wick and cool then why is an extra layer needed? Creating air pockets, lifting the jersey off the skin, etc doesnāt check out for me.
I have a sleeveless bontrager baselayer that looks kind of like a fishing net. Only really wear it on hot days because like someone else said, I find it keeps me cooler and my jersey more dry.
Iāve had a speed crash which happened in a race where it was cool enough I was wearing a short sleeve base layer under my jersey, I was glad I had a base layer on. I slid enough that besides being shredded, my jersey actually melted in spots (actually pretty common with modern fabrics but it was impressive). But there was not quite enough skidding to blow all the way through the jersey AND the base layer plus the base layer let the jersey slide over it which helped too. I give the base layer credit for really cutting down on the road rash (at least up top . . .). Think of a base layer as a kind of MIPS system for your skin A sleeveless base layer would not protect your shoulders but it might help on your torso.
As I mentioned way earlier in this thread, I find a sleeveless base layer to really add to my comfort in several different ways and the hotter it is the more I like it. To each their own I guess.
TR did a good item on summer base layers, all the marketing hype about them wicking sweat away from the skin faster is just that, marketing hype, they actually make the evaporate of sweat more complicated. Iāll wear one in autumn or on fresh starts but in the heat of summer I ll often forgo a base layer now.
I wore mesh base layers in high temps and high humidity for years and they did help me feel cooler and prevent nipple chafing, but in the last few years super high quality mesh hot weather jerseys have been a real game changer for me and I gave up the base layer with no negative impacts.
Yep I think Iām going to trust the TR podcast breakdown on this one where Chad cited research that you want the least thickness of material between your skin and the air, and that means no base layer.
This is a case when you should do what the pros do, donāt recall seeing any base layerās during very, very hot TDF. Bet we wonāt see many in upcoming Vuelta. Less is more.
A sleeveless base layer would not protect your shoulders but it might help on your torso.
Also, Iāve got this great used car, it runs perfectlyā¦