I/O Cross Trainers

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Not minimal. Not runners. Not sneakers.

Versatile inside/outside trainers that thrive both on the trail and in the urban jungle. They combine a durable performance upper, a compression molded EVA midsole, and a dual compound rubber outsole that’s both grippy and made for mileage.


Challenge Leather™ & Cordura Upper

Uppers are constructed from breathable 1000D Cordura utilizing polyester (instead of nylon used in our Rucksacks) 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 padded tongue provides comfort and protection against lace bite.

Premium Suede Heel Counter

Wraps inside, around a supportive, injection molded plastic heel counter. This combo stabilizes your heel as the suede leather prevents the kind of friction that causes hotspots and blisters.

Wide Toe Box

Generous forefoot area lets your toes breathe. Over time and distance during any activity including rucking or traveling, your feet will swell. This extra space reduces the friction that can occur if your feet rub against the insides of your shoe.

Custom Compression Insert

The I/O Cross Trainer’s insert is not your normal worthless, flat, cheap single foam insole. Our custom insert uses a dense compression foam system that supports your entire foot from heel to toe - including contoured arch support - throughout the duration of your foot strike.

One Shielding Drain Hole

Keep sand and debris out and expel water with old fashioned technology that just works - with every step, you push the water out the side of the shoe.

Midfoot Webbing

2" engineered knit webbing for additional midfoot stability. Not just a fashion statement, the signature webbing along the side helps keep your foot stable during quick movements and on uneven ground.

Supportive Heel-to-Toe Drop

Classic powerlifting shoes have a 20mm+ heel-to-toe drop (and meant for nothing else), running shoes are all over the place (according to the latest fad), Chuck T's are zero drop (and painful over all the miles). Our shoes are 10mm so you have the mobility you need for high performance training with enough millimeters to keep you fully supported while rucking.

Compression Molded EVA 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.

Dual Compound Rubber Outsole

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.

No Spacer Mesh

Spacer mesh is soft, squishy, and feels comfortable to your hand when you touch it. But it’s a trap, literally. The first time spacer mesh looks at any kind of water, your shoes get heavier and they stay that way. So we use neoprene that doesn’t absorb and doesn’t stink.


"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
Founder, GORUCK


“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.”

-Cadre Ricky V
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


What Size Am I?

I/O Cross Trainers run slightly large with a wide toe box, which allows your toes to spread out over time and distance. We recommend going a half size to a full size down from what you wear in MACV-1’s or other true to size shoes to account for increased flexibility in the upper (and you might not be wearing thick wool socks like you would with MACV-1’s). When in doubt, purchase two sizes and keep the ones that fit and return the pair that doesn't with our free and easy returns.



The I/O Cross Trainer’s wide toe box, locking heel counter, and contoured arch support via the custom insert make for a truly unisex shoe. Sizing begins at M4/W6 to allow for a full range of women's size options. See the size conversion chart below to find your size.



Inspired by old school cross trainers with added support for your feet over all the miles. They're also versatile so that you can do the work inside and outside of the gym.

NEW! Redesigned neoprene tongue and increased flexibility in the upper for even less break-in time.

Specs & Materials
1.63 LBS
Weight (One Size 9 Boot):
0.8125 lbs (13 ounces)
Scars Guarantee:
Made in USA:
Dimensions (Size 9):
12"L x 4.5"W x 4.6"H
Shaft Height:
Upper Materials:
Full-grain Challenge Leatherâ„¢ & 1000D Polyester Cordura
Drain Holes:
1 Per Shoe
Neutral last (straight from heel to toe)
Neutral with significant support and stability
Lightweight EVA
Custom Compression Insert included
High traction rubber
Heel to Toe Drop:
Made in Vietnam
Care Instructions:
Remove insert. Hose them down thoroughly and let air dry (won't take long). Do not use washer/dryer - it's easier this way.

Scars Lifetime Guarantee

You break it, we fix it. All GORUCK built gear, apparel, and footwear comes with our Scars Lifetime Guarantee. Does not apply to third-party gear and apparel.

Free Shipping at $35+

All USA orders over $35 to the lower 48 qualify for FREE No-Rush Shipping. No promo code needed. Does not apply to international orders.

Easy & Free Returns

Don't like it? Send back any full-priced item within 30 days of delivery with free return shipping in the USA. Does not apply to closeout items on sale.