Best base layer for cold-weather outdoor exercising that won't break the bank.

I’m in search of base layer clothes that I can use for both running and skiing. I have a set of silk tops and bottoms that work fine but I only have one set. If you have a preference, what do you like? Silk? Thermasilk? Wool? Something else?

As always, links are appreciated. Thanks.

Check out Muffin’s post #59 in the MPSIMS thread “Where have all my extension cords gone?” for the definitive answer to staying warm in the cold.

The key is keeping out the wind. Where I live, temps go below freezing only occasionally though below 36F is common in winter.
I’ve done fine with fleece headband, single wicking top, windbreaker (shell) jacket or vest, wool gloves, windproof underwear or boxer-brief style running shorts, tights, regular socks and shoes.
You may need to add or subtract depending on your running pace.

Definitely merino wool. It’s expensive but you only need one or two; wool is naturally anti-microbial and does not retain odors – air it out overnight and you can wear a shirt for weeks or even months between washings. Bottoms, of course, are a bit different and will require laundering somewhat more often; bottoms are often a blend of wool and something else for durability (a trick of long distance hikers is to turn them inside out each day to go longer between launderings).

I strongly recommend trying Smartwool NTS (Next To Skin) for your first merino wool shirt. You might find some other brand fits you better if you are built like a weightlifter or have some other specific fit situation but be aware that many of the other brands sell several different grades of wool and what appears to be a bargain price might actually be their cheap itchy scratchy stuff, not their top of the line soft as cotton line – Smartwool is always soft and high quality. I am not saying you shouldn’t try other brands, just be aware that many of them sell different qualities of clothing that may confuse the consumer.

What do those numbers mean? You’ll see things like 150g/m2, 200g/m2 – those are the weight of the fabric in grams per square meter; 150 is very light summer weight, 250 is pretty warm. You’ll also come across numbers like 17.5 microns and 18.5 microns – those are the diameter of the fibers in the fabric and will tell you how scratchy it may be; most good quality merino wool baselayers will be either 18 or 18.5 microns as bigger will be scratchy (an army blanket is probably about 30 microns) – you can find shirts at 17.5 but expect to pay for the luxury.

Never use fabric softener when washing merino wool (or any other wicking fabric), it clogs up the wicking action. Also, don’t use Woolite. Use a good wool or tech wash or soap rather than detergent so you don’t wash away the natural lanolin; I usually use Dr. Bronner’s soap and occasionally do an overnight soak in Kookaburra Wash (no rinsing – leave it in) to restore the lanolin.

So very true! I have cycling and running shirts and shorts last several years by not using fabric softener - a very good tip! Also, hang-dry all tech-/wicking fabrics rather than put thru the dryer.

When I first started running, I was able to pick-up several tech-fabric shirts (Coolmax?) for around $5 - $10 each on the clearance rack at Kohl’s or even Target. These work great as a base layer, and you need not worry about them being ugly since you should be wearing another layer or two over them. I ended-up with an Asics running pull-over, which I can use with one layer under it in temps down to the 20s (I heat-up fast). A proper cycling jacket and jersey over the base layer keep me cocooned fine for cold-dry riding.

I have since acquired a number of tech shirts as swag from running events, with a few long-sleeved ones as well - all make an an excellent base layer, and I use them that way for running, cycling, and skiing. The key is the wicking fabric, as Turble describes.

Merino wool rules. In fact I wear merino wool briefs every day.

I strongly suggest Eucalan for washing, and also dont use the dryer unless you have to, they dry fine overnite, a fan helps.