Trail Test Day: Five Running Products Put Through a Hot 10K

Introduction

Race days are the best kind of gear test. Nothing tells you how a shoe, a pair of shorts, or a set of earbuds really behaves like a few miles of hills, heat, and uneven ground. That was exactly the plan for the Brighton Trail Weekend 10K: run the race, and put five pieces of running kit through their paces at the same time.

The lineup for the day covered a lot of ground: the New Balance FuelCell Summit Unknown v3 trail shoes, Under Armour Speed Pocket Trail Shorts, Under Armour Dry Run Crew socks, Oakley Resub Zero sunglasses, and Soundcore Sport X10 true wireless earbuds. Here is how the race went, and what each product delivered.

The Race: Brighton Trail Weekend 10K

This was the first edition of the race, and there were the small teething issues you might expect: a start delayed by about 20 minutes, and stretches of the woodland section where a couple more marshals would have helped. The route itself was well marked, with arrows drawn on the ground and plenty of signage, but there were points where runners were spread thin enough that losing concentration could mean losing the course.

The terrain was honest. The opening 3 to 4K climbs steadily from low ground up into the hills, and that stretch is genuinely tough if you are not trail fit. Once over the top, the course levels into undulating sections across woodland and fields, and the final 2 to 3K is largely downhill, making for a beautiful and satisfying finish.

Organization beyond the start was strong: free bus passes to get to the start, a car park close to the venue, good marshaling on the fast sections, a wooden medal, and a genuinely wearable cotton t-shirt. A hot, sunny day made it a proper test for everything on the checklist.

New Balance FuelCell Summit Unknown v3

FuelCell is a midsole foam usually associated with New Balance road shoes, known for its soft, slightly bouncy ride. Seeing it in a trail shoe is unusual, and it is what makes the Summit Unknown v3 interesting. On the day, it delivered a comfortable, almost road-like ride with a bit of extra grip and more support around the upper than a typical road trainer.

The course conditions suited it: hard compacted trail, some mud, and rockier sections. On softer ground, the foam would be less of an advantage, so this is best thought of as a balanced road-to-trail shoe rather than a soft-ground specialist. The trade-off showed on uneven ground and tight corners, where the fit occasionally felt a touch wobbly. For serious racing or genuinely technical terrain, something that locks the foot down more firmly would be the safer choice. For general trail running and mixed road-to-trail use, though, it is a really enjoyable shoe.

Under Armour Dry Run Crew Socks

Sometimes the least glamorous piece of kit makes the biggest difference. These are general running socks rather than anything trail-specific, but they were exactly right on the day: thick enough to pad out an unfamiliar shoe and protect a healing blister, yet still breathable and comfortable over a hot 10K.

Thick-but-breathable is a hard balance to strike, and these pulled it off. If you are breaking in new shoes or just prefer a cushioned crew sock for running, they are an easy recommendation.

Soundcore Sport X10

Sport-focused true wireless earbuds are a crowded category, and the Sport X10 competes on fit and value rather than premium sound. The standout feature is the swinging rubber ear hook: it folds neatly into the charging case, then flips out to hook over the ear for security. During the race, the fit was excellent. They stayed put from start to finish and never felt like they would shift.

The sound is fine rather than impressive, and the active noise cancellation was hard to distinguish when toggling it on and off mid-run, so neither is the reason to buy. Controls are simple, with a single button on each earbud and a straightforward press pattern. At around £89, they sit well below premium sport options from brands like Jabra or Jaybird, and the secure fit alone makes them a compelling value pick for runners.

Oakley Resub Zero

Sport sunglasses are a matter of taste, and the Resub Zero wins points for being subtler than many visor-style options. They have been used before, but never in a race, and this run confirmed what earlier wear suggested: they are genuinely comfortable.

They sit neatly against the nose, barely register on the head, and required zero adjustment over the whole race. No bouncing, no jumping around. For a hot, sunny trail 10K, that is exactly what you want from a pair of shades. At around £200 they are a significant investment, but the comfort and restrained look make them appealing even for someone who usually avoids sport-style eyewear.

Under Armour Speed Pocket Trail Shorts

Split shorts are a divisive category, and they were approached with low expectations here. The verdict after one hot race: a genuine convert. They are extremely light and breathable, with plenty of vents in the fabric and the extra airflow that split legs provide, and they stayed comfortable throughout.

The rear zip pocket is small, best suited to keys, but well positioned so it does not bounce. The headline feature is the Speed Pocket in the front waistband, which expands to hold a surprising amount, comfortably more than you would expect. It lacks a zip, so a phone or anything irreplaceable feels like a risk, but for gels and soft items it is a clever addition. Lightweight trail runners looking for airflow on hot days will get a lot out of these.

Buying Advice

Each product here earns its place for a specific runner. The Summit Unknown v3 suits balanced road-to-trail running on harder terrain. The Dry Run Crew socks are a low-risk comfort upgrade for anyone who likes a cushioned sock or is breaking in new shoes. The Sport X10 offers secure fit and simple controls at a mid-pack price, with sound as the compromise. The Resub Zero justifies its premium tag through all-day comfort and a subtle design. The Speed Pocket Trail Shorts are the surprise pick, ideal for hot-weather runners willing to try split shorts.

Conclusion

A hot, hilly first-edition trail 10K is a fair test, and most of this kit passed with room to spare. The shorts were the pleasant surprise, the socks quietly excellent, the earbuds a value-driven fit-first option, and the sunglasses a comfort win. The shoe was the most nuanced: great on hard and mixed trail, less convincing on technical ground. Match each to your own terrain and priorities, and there is something here for most runners.