



I/O aka
Inside/Outside
Versatile inside/outside trainers that thrive both on the trail and in the urban jungle. From work, subway, bar, or gym, to rucking, the challenge, hiking, and travel.

Durable Performance Upper
Uppers are constructed from breathable 1000D CORDURA® utilizing polyester for more flexibility to contour to your foot.
New full-grain military spec Challenge Leather™ on the toe cap, eyestay and heel tab is designed to minimize scars and scuffs.
2” knit webbing across the midfoot adds stability and a neoprene tongue provides comfort and protection against lace bite.

Lightweight & Supportive Midsole
The lightweight compression molded midsole provides the cushion and support you need without weighing you down. Saving ounces here also means we can use a more versatile rubber outsole and the most durable upper materials available.

Outsole Made For Mileage
New dual compound rubber outsole adds traction and durability with understated protection at the toes of the shoe for when you're rucking in rocky terrain or doing push-ups.
Forefoot rubber is formulated for increased grip while the heel area is formulated for abrasion resistance and longevity.
Developing the I/O Cross Trainers
I’ve lived in some version of these for 18 months. We tested the I/O’s on concrete, trails, inside the gym and outside in every season with the gym on our backs. We’ve traveled all over the world in the same pair of shoes, been on our feet all day every day for long distances and long stretches of time, then done it again the next day feeling good. Every new prototype was an opportunity to adjust a millimeter here, a millimeter there, until they were just right and ready for our kind of daily lives, which means they have to be ready for anything when you are.
Places they've been tested: concrete, trails, the beach, muddy obstacle course (Savage Race), technical obstacle course (Fort Carson), the gym, the bar (OK, plural, bars), biking to work every day, long flights, short flights, train rides and lots and lots of adventures on foot, the 26.2 Star Course in San Francisco, always taking the stairs, summer, fall, winter and spring, hot and humid, cold and dry.
Jason McCarthy, GORUCK Founder![]()
These trainers are my new go-to gym shoes — even for lifting. They’ve got all the support (and I mean ALL the support) you need to wear all day, every day.
Ricky V, GORUCK Cadre, Army Special Forces![]()
The I/O is a true multi-purpose shoe — great for travel (getting to and wandering around a city) — and just as great for training (rucking or hitting the gym). This shoe really does it all, and does it well.
Richard Rice, 5th Special Forces Group, US Army 1966-94![]()

Support. Support. Support.
Ruck Trainers
The I/O Cross Trainers are proudly NOT minimal, they're NOT runners and they're NOT sneakers. They are ruck trainers with tons of support.
Support that manifests under weight and when moving weight.