Asics’ 3D-printed sandal offers post-workout comfort

The theory and practice of marginal gains is finding and fixing hundreds of little things that add up to something big. Asics believes that runners can be beneficial both at home and on the track. This is the playing field for the Actibreeze 3D, a pair of 3D printed sandals with a grid structure to improve cooling and breathability. The idea is to prevent your extremities from getting sweaty and tense after a run so you’re much better prepared for your next run. I’ve been wearing a pair for a few days now and while they keep your feet cool and dry, they’re not perfect.

When you unpack them, the first thing that strikes you is how heavy they are, as each sandal – although they look more like slippers – weighs 350 grams (12 oz) for my size 11. They’re also much larger than your average pool slide, thanks to the overbuilt sole and the lattice that goes over the top of your foot. Obviously this is to help the air flow under your feet to cool them down after a long run and I experienced this after a fairly intense training session. It helped that we’re enduring a climate change-enhanced heatwave to really ram home the lack of sweating. It’s a much nicer experience to wear than what I would normally wear, which is a pair of $15 Havaianas.

The 3D grid was designed to offer the greatest possible comfort when boarding which means they are quite springy. Not like walking on air, but you can feel the sole compressing as you walk and rebounding when you take a step. I don’t know if the effect is more pronounced here than other 3D printed soles on the market, or if it’s amplified because you’re barefoot and not wearing socks. Certainly, it takes a bit of mental calibration to compensate for the amount of travel you’ll experience at every step. Maybe people wearing these novelty moonboots won’t find them a big deal, but when you’re coming from something flat, it’s a noticeable change.

Here’s the problem – obviously 3D printed material is made of springy plastic, but it’s still plastic with its mostly hard, not particularly compliant structure. If you wear these for an hour, the soles of your feet will look like you’ve stood on a sieve, the skin covered with a grid of small squares. Whatever the benefit of your feet at the macro level, you have to endure the minor annoyance of having your skin being put through a mesh. And, on a related subject, because it’s a hard, waterproof plastic, it’s not the ideal surface for putting your feet in close contact during a heat wave. This is perhaps the only area where my $15 Havaianas excel because so little material makes contact with the toe of my foot. But if you’re only wearing these for two or three hours after a run, that shouldn’t be too much of a problem.

Asics’ Actibreeze 3D are listed on the company’s website for $80, although they’re not currently available for delivery. The company tells me that the stock will be available again in select markets this fall.