Jen reviews the Inov-8 AT/C Thermoshell lightweight insulated jacket.


Inov-8’s Thermoshell AT/C is a lightweight, packable, insulating jacket designed for running in cool, changeable conditions and at different levels of intensity. It’s available in men’s and women’s versions, both of which come in black with red/cherry zip detail. There’s a deep centre front zip for venting and an integrated chest pocket that the jacket will stash neatly into. It has a drawcord hem, soft, elasticated cuffs and thumb loops. The Thermoshell was a 2016/2017 ISPO AWARD GOLD WINNER in the Performance Apparel (outer layers) Category.

Weight: 223g/198g men’s/women’s small.

RRP: £130

Outer Fabric

The Thermoshell has a Pertex Quantum ultralight windproof outer shell with breathable, four-way stretch under-arm and side panels. There are reflective Inov-8 logos on the front, back and sleeve.

Polartec Alpha Insulation

The insulating layer is Polartec Alpha, a super-slim, lightweight, polyester fabric originally designed for the US Special Forces. Polartec’s aim was to develop a fabric that would protect soldiers moving stop-start through variable mountain terrain, so it’s no surprise it works brilliantly for long days out running in changeable weather too. Polartec Alpha is a clever combination of a solid mesh core surrounded by hydrophobic lofted knit fibres, with a protective outer layer. Unlike many other insulating materials it’s warm straight away, even after being compressed, and is still warm when wet. It’s quick-drying and provides excellent moisture management when you’re working hard. Even better, it’s bluesign certified, so it conforms to strict manufacturing sustainability criteria.

In Use

I have to say that since I first unpacked this jacket I’ve rarely taken it off. The fit is excellent – Inov-8 sizing is always a little on the small side and this jacket is an athletic cut, so if you tend to be between sizes go for the larger. The jacket feels snug without being restrictive and the women’s version features a drop tail which adds warmth, comfort and extra coverage. I often take a pack with me when I’m out running, so changing layers can be a time-consuming business. I’m also often stopping and starting, taking photos or route-finding, so I was keen to see if the Thermoshell lived up to its promise of being able to handle variations in weather and effort level. I’ve used the Thermoshell over a Merino baselayer for long coast path runs in rain, hail, sun and strong winds, taken it out on the fells and stashed it in my pack on warmer days ready for the evening chill. I’ve run, walked, climbed and played on the beach in it… and it’s absolutely brilliant.

it’s absolutely brilliant.

The genius of this jacket lies in the combination of fabrics used: insulating, windproof panels in most areas but stretchy, super-breathable sections along the underside of the arms and down the sides, exactly where you need them. It works perfectly when you’re running, balancing protection from the wind with airflow, movement and superb comfort – it really does move with you, whether you’re running, taking a pack on or off or scrambling up the side of a mountain. The Polartec Alpha insulation seems to handle changes in temperature with ease, providing a protective layer that’s warm enough for standing around, even in wet weather. It’s also breathable enough, combined with the venting features on the jacket, to still be completely comfortable when you’re running hard.

The details are excellent – elasticated cuffs are soft against the skin and, along with the stretch panel in the arm, allow the sleeves to be rolled up for extra venting. The thumb loops are great for colder days and a zip guard protects your chin. The chest pocket is a useful size – it’s completely flat when not in use, but large enough to fit something like a compass or pair of gloves. Taking smock-style jackets off on the run can be awkward, but with the stretch panels the Thermoshell slides over your head with ease. The jacket looks great too – I’d happily wear it to the pub at the end of a long day of adventures.


A seriously impressive piece of kit from Inov-8. Expertly thought-through in every detail, it’s a perfect choice for running and adventuring throughout the cooler months as well as stashing in your pack for summer evenings.