Worthing 10K Race Test: Saucony Endorphin Pro 4 and Shokz OpenFit Air

Introduction

The Worthing 10K made a perfect test bench this time around: flat course, spot-on weather, and no pressure to chase a personal best. That freed up the day for two pieces of kit that deserved a proper race run-out: the Saucony Endorphin Pro 4 and the Shokz OpenFit Air. Neither had been raced before, so the 10K distance offered a fair, honest look at how both actually behave when it matters.

The Race: Worthing 10K

Worthing is a seaside town on the south coast, and its 10K is one of the bigger summer races in the area. Unlike smaller coastal events that squeeze runners onto pavements along coastal paths, this one uses proper roads through and around Worthing, which makes for a much more comfortable racing experience. The route is very flat: through the town, out around a loop by a field, and back to a lively seaside finish. There is one water station around the 4-5K mark.

The main variable is the weather. South coast races live or die by the wind, and a bad day can ruin any chance of a fast time. This day was about as good as it gets: sunny, not too hot, with barely any breeze. Crowds were out in force enjoying the sunshine, and the finish along the seafront, with coffee and ice cream in hand, is hard to beat. For anyone thinking of a weekend trip combined with a race, it is a strong pick, especially paired with the park run and Worthing parkrun the day before. The finisher’s time came in at 39:25, about two minutes off a 37:30 PB, which was expected given the current fitness base ahead of a build-up toward the Valencia Marathon in December.

Saucony Endorphin Pro 4: Better Over 10K Than Expected

The Endorphin Pro 4 has been a bit of a puzzle. Used heavily in marathon training blocks ahead of London and Boston, it never quite clicked in training. The Pro 3 was a long-time favorite, and the Pro 4’s added layer of HG foam changes the ride noticeably, taking away some of the bounce and energy return that made the previous version so appealing. That hesitation is exactly why it went unused in races until now.

Over the 10K, the shoe performed better than expected. It feels firmer than the Endorphin Pro 3, but it is undeniably fast and nippy, exactly what you want from a carbon plate shoe at 5K and 10K distances. It is comfortable, disappears on the foot, and handled a couple of quick kilometers around 3:30 per kilometer without any issues. The honest caveat remains: the dual foam design does not deliver the softness and energy return wanted for marathon or even long-run duty, though half marathon distance seems reasonable. For shorter races, it is absolutely fine, and no other shoe would have made a meaningful difference on the day.

Shokz OpenFit Air: Comfortable and Surprisingly Reliable

The OpenFit Air earbuds use an open-ear design with sound directed into the ear rather than bone conduction, and the fit held up across a training run and a full race. Worn alongside sunglasses and a cap, there were no fit issues at all, and no pressure or discomfort. The sound is loud enough that podcasts are actually listenable on the road, a real step up from bone conduction headphones, where spoken content becomes nearly impossible to follow on busy streets. Racing with a podcast would still be a stretch in loud crowds, but music works well.

Touch controls were the biggest worry going in, since sweaty or accidental presses can be frustrating, and physical buttons are usually preferred. In practice they behaved well for skipping tracks, with one exception: water splashed on the earbud during a water station stop confused the touchpad and paused playback until it dried. With dry fingers they work fine. The only other quirk is how easy they are to forget you are wearing, since they are so light and unobtrusive that a dropped bud could go unnoticed. The silver design looks sharp, too.

Which One Is Worth Buying?

Both pieces of kit earned their place over this race distance. The Endorphin Pro 4 makes sense for runners focused on 5K to half marathon racing who want a fast, comfortable carbon plate shoe and can accept a firmer ride than its predecessor. It is less convincing as a marathon shoe for runners who value plushness and bounce over long distances.

The OpenFit Air suits runners who want open-ear awareness with sound quality good enough for podcasts on quieter roads, and who can live with touch controls that need to stay dry. Anyone who has struggled with the fit of other open-ear designs may find this one more forgiving, though sweat-heavy sessions or water splashes are worth keeping in mind.

Conclusion

The Worthing 10K delivered exactly what a low-pressure race test should: clear answers. The Saucony Endorphin Pro 4 is a better short-distance racer than its training reputation suggests, while the Shokz OpenFit Air proved comfortable, good-sounding, and reliable through a full race, with only the wet touchpad as a real complaint. Neither is flawless, but both are easy to recommend for the right use case.