Orca Aesir Flex review: A high-performance and flexible wetsuit primed for swimrun racing

Orca has been producing swimrun kit for years and has now consolidated its range with two core swimrun suits, the Aesir on test here and a more budget option in the form of the Vanir ($259/£199), which you can read about in our test of the best swimrun wetsuits.

Orca tells us the Aesir is the most elastic wetsuit in its range and it’s certainly supple. That’s thanks to the stretchy, jersey-like neoprene along the legs up to the waist, plus the use of Yamamoto 40 neoprene.

This design’s a great help during the run sections of a swimrun, as run stride feels unrestricted, while the thin, breathable material helps to prevent overheating.

Swim performance

In the water, the Aesir feels like a second skin. The DuraSkin 2 material used in the lower torso aims to protect the suit from abrasions during racing, boosting durability.

Naturally, the legs aren’t as lifted as you’d find in a full-length triathlon wetsuit, but this is why swim runners often race with a pull buoy and buoyancy inserts in calf guards to lift trainer-laden feet in the water.

As such, I’ve had no trouble with sinky legs, the buoyancy profile of the Aesir raising my body into a hydrodynamic and ergonomic position for front crawl during swim sections.

During swim stroke, the flexibility across the shoulders gives ample range of movement and the arm holes with slim cuffs sit just right, without uncomfortably squeezing the biceps.

There’s no rubbing along well-located seams, or chafing on the underarms, which is a big plus, as this is a common issue with swimrun kit.

Sarah also tested the suit and adds: “On the run, it’s super light, offers fabulous flexibility and the easy to remove jacket-top construction makes half removal effortless to maintain a comfortable temperature.

“The extra space created by the design makes it quick and easy to get back over the shoulders making transition back at the water’s edge simple even whilst clambering over rocks!”

Features and fit

Some may be confused with the zip located along the front of the suit, but this is a normal set-up for a swimrun wetsuit as it allows for easy unzipping on the go.

It’s easy to use, while the top Velcro closure doesn’t dig in or cut off our airways as we feared it might, though I did get some rubbing that was sorted by some wetsuit lube.

Another big pro for the Aesir was the detachable sleeves, which are essential for racing in a range of conditions (a thermal version, the Aesir Thermal, available for $499/£399), though I prefer wearing the suit sans long sleeves to avoid overheating on the run.

What’s unusual about this suit is that it features a split design where the legs and front of the torso split apart completely at the bottom (but the two halves are still connected) to give the wearer better fit flexibility and comfort.

Sarah also notes that the build feels extra durable in testing: “The Aesir’s clever construction with the more hardwearing fabric on the shorts proved durable. There is no evidence of abrasion from the rock encounters I had and there is no sign of wear on the inner legs after testing and racing. The seams are reinforced in this area which will also help with durability.”

This also means that the suit should fit a wider range of sizes, especially those on the taller side. The downside to this is that the zip’s more fiddly to do up on the go pre-swim leg if you want to wear the suit half-down during a run section.

Another feature I’d adjust is the lack of tow line attachment loops on the suit, though this isn’t a deal-breaker as you can add your own swimrun belt.

Meanwhile, built into the inside of the back of the suit is a 6in/15cm x 4.7in/12cm pocket. It’s not easily accessible on the go unless you unzip the suit, but could be useful for storing small safety necessities like a whistle and gels. Tester Sarah notes that the storage could be improved by adding more options and a zip-up section.

Orca Aesir Flex swimrun wetsuit specs

Price	$549 / £449
Fabric	Yamamoto 39 and 40 (95% neoprene / 5% nylon); SCS coating; DuraSkin 2 abrasion resistance
Features	Removable sleeves; front zip; inner pockets; backpack included
Sizing	Women: XS-XL (Orca sizing) Men: 4-11 (Orca sizing)