Sealskinz Runham foldable running cap review: A lightweight, portable option for warm-weather hiking and trail running

First impressions

A decent cap can make all the difference when running or hiking in stifling summer heat, providing essential shade and protection from the elements as you race around the wilderness.

The new Sealskinz Runham cap is an ultralight option for summer excursions, designed to keep you cool and cut all unnecessary weight as you chase that elusive PB.

It's made from a stretchy combination of nylon and spandex, which strives to deliver a snug fit and plenty of breathability when things get sweaty.

These UV protective fabrics aren't waterproof, as the Runham cap is built for lightweight performance in warm climates.

Sealskinz also claims that this cap is moisture-wicking, meaning it moves sweat from your head to the cap's exterior and dries quickly to avoid saturation and extra weight.

The plastic brim provides welcome shade on the trails and splits down the middle, so you can fold it in half and fit the cap into your pocket or backpack without it taking up too much space.

It's available in one size, which can be adjusted using a handy Velcro strap.

Sealskinz Runham Cap: on the trails

I was lucky enough to get my hands on this new Sealskinz cap in May at the Keswick Mountain festival.

In the month since, I've tested its mettle in the scorching temperatures of a British heatwave, wearing the Runham on plenty of sweaty trail runs and hikes. I've taken this cap all over the English countryside, and even up the odd mountain in Cumbria's Lake District National Park.

Here's how it performed:

Fit and comfort

The Runham cap has a comfortable, snug fit. The combination of nylon and spandex proved itself stretchy enough to wrap around my head and remain put, without ever feeling too tight.

The sticky Velcro strap remained effective after plenty of use and allowed me to adjust the cap to fit precisely around my skull.

It stuck to my head throughout testing and never threatened to blow away, even in strong winds.

The Runham cap performs particularly well when the sun comes out, thanks to its breathable exterior and moisture-wicking capabilities. Its airy fabrics kept me cool in temperatures where I would've been dripping with sweat in a less breathable cap.

Sweat is inevitable when exercising in the heat, but this cap does a great job of managing it by maximizing airflow and evaporating sweat with fast and effective moisture-wicking.

It's also quick-drying, shedding sweat or rainfall fast.

Weight and portability

Weighing just 1.5oz (43g), this cap is an ultralight option for speeding through the trails. Its minimal bulk was noticeable as I ran and it felt more like an extension of my head than an additional item of clothing.

Its foldable plastic brim, which provided effective protection from the sun, is also light and didn't snap or bend in testing.

With running shoes, a water bottle, and more, a cap is unlikely to be the heaviest thing you'll bring on the trails, but this one's minimal weight will be appreciated by those who want to save every available gram.

Its slim, lightweight nature is also useful when you're travelling, as it adds practically nothing to a backpack and is almost unnoticeable in your pocket. Simply fold the split brim in half and tuck it neatly into either one.

I found this very handy, as it minimized the need for extra storage I didn't have to hold my cap if I didn't fancy wearing it.

Price

The only thing holding this otherwise superb cap back is its price. There's no doubt that the Runham cap is an excellent choice for warm-weather running and hiking, but its $55 (£30) price tag may make you think twice.

The Salomon XA, another high-quality cap with many of the same features as the Runham, is available for as little as $25 (£22). It also tops our expert list of the best running hats and caps.

If it were similarly priced, the Runham cap would be my nailed-on favorite. As it is, this warm-weather sunshield loses marks for its excessive price tag.

Also consider

Comparison table

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• How Advnture tests products