Arc'Teryx Atom LT Vest


Core insulation is critical in the colder months. While much is made of heat being lost through head and hands, keeping your torso toasty is the key to comfort on the hill. The most efficient means of adding extra warmth without carrying excessive bulk or weight is with a gilet (often referred to as a vest, or, in more traditional language, bodywarmer).

Gilets offer a lightweight, low-bulk alternative to insulation layers such as fleece or puffy (synthetic or down) jackets. They provide heat where you need it, leaving arms free to move. Some compress into their pockets or stuff sacks, making them compact in a rucksack. Some are body hugging, designed to be worn over a base layer; others are cut to ‘go large’ for instant warmth when you stop moving. Because weight and bulk are important factors for most of us, I’ve chosen to test close-fitting gilets, intended to be layered over base or base plus mid. I like my gilets to also fit over a shell jacket – soft or hard shell – during rest stops, so if you plan to do this too, please try your chosen garment for size over your outdoor clothing to be sure it fits at collar, arms and hips.

This gilet, from Arc'Teryx (versions for men and women) is one of the very best. It's been in the Atom LT range for some years, with small tweaks, and is a proven favourite (the other Atom LT garments are jackets with different degrees of insulation).

It has a winning combination of supple, compressible insulation, low overall weight, stretch side panels and well-placed pockets. The stretch side panels have fleece on the inside face; as they form the underarm, they flex fluently with movement. Both the Coreloft body and side panels breathe well; the Tyono20 nylon face fabric is durable, and efficiently wind and water resistant. Zipped side pockets sit just high enough to avoid a rucksack hipbelt, and the inside chest pocket is a decent size too.

Women’s Medium was the right fit over my 36A chest, but bustier women might need to go up a size. The collar, lightly brushed on the inside face, zips up to just under my chin. Fit is perfect over a base layer and a thin fleece, but it can’t be fully zipped up over anything bulkier. It can still be worn over  a mid-layer, soft-shell or even a waterproof during a rest-stop, without being fully zipped. After prolonged testing through winter and spring (ski touring, mountain biking, hiking and yes, visiting the pub), this started, and finished, as my outright favourite for the season: weight, fit and performance are unbeatable.


Best for: core insulation in the colder months. Ideal for skiing, ski touring, mountain walking, even mountain biking

Price: £120 (2016)

Colours: wide selection

Weight:  195g

Length: 60cm, women's Medium

Fabric: body: Tyono20 (nylon); side panels: Polartec Powerstretch (88% polyester, 12% elastane)  

Insulation: 60 g/m2 Coreloft (polyester)

Sizes: women XS-XL, men S-XXL


Stockst information:

Arcteryx Atom-2 atom-1

Atom LT Vest worn over a windproof (which was the same colour as the vest...) mountain biking in the Tarentaise valley, France, Autumn 2016