A combination of breathability and protection is key for these activities and, since you’re earning every step, so is weight.
Mixing silk and wool as Falke does in its Longsleeve ($150; falke.com) lands that optimum balance: temperature variability and soft next-to-skin from silk and wicking, no stink and warmth-when-wet from wool.
Likewise, Patagonia’s Nano Air Light Hoody ($300; patagonia.com) is like a thermostat, auto-adjusting to your needs. A proprietary insulation and highly porous fabrics allow this thing to breathe even while insulating—you probably won’t need to take it off.
That doesn’t mean you shouldn’t bring a shell. Just make it a light one that can stand up to powerful winds without turning into a greenhouse. The FlyLow Genius ($530; flylowgear.com) is made from a lightweight version of Polartec NeoShell—a waterproof and highly breathable three-layer shell. The minimalist design with huge pit-zips keeps it breezy when you wear it, but when you don’t, the 470-gram penalty is negligible.
Since legs do most of the work, they need the least protection and the most breathability, so trade water- and wind-proof pants—unless it’s really nasty—for soft shells like the Black Diamond Dawn Patrol LT Ski Touring Pant ($250; blackdiamondequipment.com). Mesh-backed side-vents help the porous fabric dump hot air, but the double-weave and water-repellent material is plenty durable for most days.