Revision as of 15:52, 6 August 2018

If you're in the market for a reasonably light (8.4oz/240g) road shoe that's somewhat firm and fits a healthy human foot, then the Duo is a good option. The Duo is not without its flaws, the main one being a tendency to pick up small stones under the sole. The other issue is that the sole seems to wear faster than you might expect. This is not as bad as early versions of The One, where the sole used to abrade like it was made of milk chocolate, but it's a little more than I would like. I'm only at about 120 miles, and there's already slight signs of wear on the outsole. On a more positive note however, the Duo is shaped like a healthy human foot, so it won't induce bunions, nor require you to have bunions to fit correctly. The Duo even has a little bit more height in the toe box than many Altra shoes tend to have. It's a little firmer than I would like for this weight, but that does confer some degree of protection without much cushioning, a plus point if you like a firmer running shoe. Like all Altra shoes, it's close to zero drop, with nothing to interfere with your natural biomechanics. I'm rating the Duo as "Recommended." (I use The Science of Running Shoes as the basis of how I test running shoes and what you should look for in a running shoe.)

below are some pictures of the Duo after it's picked up some small stones. The first 2 pictures are from a run along and asphalt Greenway, that has just a few patches of loose stones. The later pictures with the darker sole are after a 43-mile run along a gravel trail (the New River State Park in Virginia.) You can see the Duo was crammed full of small stones, so you're probably wondering why I wore the Duo on a gravel trail. Let me talk you through my reasoning. I didn't want to wear a thin road shoe, like my favorite Altra Solstice as it wouldn't provide enough of protection from the stones, but I didn't want to wear a full trail shoe like the Altra Timp as I didn't need that much protection, nor did I want that much weight. The Duo is firm enough to provide the protection I needed, and the raised patches provide good grip on the patches of mud and other slick surfaces. The Duo did accumulate stones very rapidly, but not enough to significantly increase the weight of the shoe or compromise the cushioning. (The stones added about 0.4oz in case you're wondering, like I was.) While I found I can cut open the toe box of a shoe and run on gravel surfaces without getting any stones into the holes, I do prefer leaving the toe box intact if I have the option. That really limits me to an Altra, or a tiny subset of other shoes that are designed to fit a healthy human foot. And I found the Duo to be quite comfortable for a 40+ mile run.

1 Characteristics

• Cushioning . The Duo has reasonable, but not great cushioning for its weight. It feels a little firm rather than hard, but my perception while running is that it's a little firmer than the numbers would suggest. This is probably because the Duo has a number of raised rings or patches of cushioning, creating an eggshell effect. Because the pressure is concentrated on these raised areas, they tend to compress a little more than the rest of the midsole. This creates a slightly softer, and more cushioned sole than you'd get from a more traditional, flat sole. I never felt that there was any unevenness from these raised areas, and the camp and you owe is a smooth and neutral underfoot. I would prefer that issue waiting this much provided more cushioning, or weigh far less, but the problem is far from egregious. However, Altra's claim of "maximum cushion and minimal weight" is somewhat laughable. It's a very long way from either maximum cushioning or minimal weight, and Altra's claim that "the cushion-to-weight ratio on this shoe is hard to beat" seems disingenuous at best. Every Altra road shoe I've measured has a better cushion-to-weight ratio! (The good news is that at least they're aware of this ratio.)
• Drop. The Duo is effectively zero drop (not all Altra shoes are zero drop, regardless of what they claim.)
• Structure. The Duo uses just one density of foam and doesn't attempt to manipulate or interfere with your natural biomechanics.
• Flexibility. While the Duo is moderately flexible and quite springy, though I doubt if there's any performance benefit to be had.
• Outsole. The outsole is the Duo's weak point. The raised areas are naturally prone to rapid wear, and the gaps between the raised areas are the worst stone magnet I've ever come across. And once they are full of tiny stones, the effective cushioning of the shoe is dramatically reduced. Even running on what I think of as a fairly clean asphalt surface, the camp and you owe manages to find a few stones to pick up. In the photos above, you can see the harder rubber outsole as its colored yellow, but even after just 100 miles or so, the wear was noticeable, and I'm typically pretty gentle on my shoes.
• Shape. Altra shoes are some of the few that attempt to actually fit the human foot. The Duo does a great job of fitting the outline of the human foot, and like some other Altra shoes there's a little headroom for your toes. In fact, there's enough headroom that I didn't feel the urge to cut open the toe box.
  
  

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• Upper. The upper is unpadded except for a tiny bit around the ankle opening. The upper is inflexible, which I prefer over stretchy uppers. For some reason, Altra claim the Duo is for "Hot Weather Endurance Racing," and while it's reasonably breathable, there's nothing particularly noteworthy.
• Tongue. The Duo has a traditional tongue that is has a tab to attach it to the laces. There's a bit of padding down the middle of the tongue, which might help a little bit with the pressure on the top of the foot.
• Lacing. The thin flat laces never came untied, something that surprised me a little given the problems I've had with the Altra Solstice, an otherwise superior shoe.
• Heel Counter. The Duo has no noticeable heel counter.

Please support this site This review was made possible by readers like you buying products via my links. I buy all the products I review through normal retail channels, which allows me to create unbiased reviews free from the influence of reciprocity, or the need to keep vendors happy. It also ensures I don't get "reviewer specials" that are better than the retail versions. Buy Altra Duo at Zappos Buy Altra Duo at Road Runner Sports Buy Altra Duo at Kelly's Running Warehouse Buy Altra Duo at Charlotte Ultra Running Company

2 A Comparison with other Recommended Shoes

If you're looking for "the best of the best" running shoe, here are my top picks. Of course, the answer will depend a little on what you're looking for, so I have recommendations for various categories. Best All Round Shoe. The Altra Escalante is my current all-round favorite. It has plenty of cushioning for its weight, it has a very springy midsole, it lasts well, and it has a shape that's closer to the shape of a human foot than most shoes. It's a great shoe for any runner, including those Starting to run. It's also a fairly easy shoe to find due to its popularity. Best Maximalist Shoe: If you want something massively cushioned, then I'd recommend the Saucony Kinvara 8. It's remarkably light and remarkably cushioned, beating Hoka at their own game. Best Optimal Shoe: For those looking to trade cushioning for speed, the Nike Zoom Streak LT 3 was my top pick, but the latest version (LT 4) falls short of it's predecessor. There are lots of great optimal running shoes, which provide just enough cushioning with light weight and minimal frills, but all have their weak spots. Probably the best option at the moment is the Altra Vanish-R, which offers great cushioning for just over 5oz/150g. Fastest Shoe: If you really want speed, then check out the Nike Vaporfly 4%. It's light, massively cushioned, and has a carbon fiber plate. Nothing comes close, not even the now defunct New Balance RC5000‏‎ or New Balance RC5000v2‏‎. There are a number of caveats; it's really expensive, it's really hard to find, and there's a significant injury risk. Best Minimalist Shoe: Merrell Trail Glove. I recommend the trail glove for road running in spite of the 'trail' moniker. It's not a fast shoe by any means, but it's comfortable and will last well. All Terrain Shoe. For trail running, I've become a fan of Altra, and I think their best shoe is the the Altra Timp, though the Altra Lone Peak is really close. Honorable Mention: It's not really a running shoe, but the Vivobarefoot Ra is comfortable, minimalist and can more or less pass as a dress shoe. I've worn mine to weddings with a suit and they've not looked out of place. You can run in the Ra, but the leather means it doesn't breathe well.

For a more detailed on running shoes see the Recommendations for Best Running Shoes. This table lists the key attributes of What to Look for in Running Shoes. For more detailed information, on the shoes see detailed shoe comparison.

It's not a running shoe, but I love the Hoka Tor Ultra hiking boot and I've tested the Altra Lone Peak Boot, the Hoka Tor Speed 2, and the Inov-8 Roclite 325 hiking boots
Older shoe reviews: Saucony Hattori Review, Mizuno Cursoris Review, Skechers GO Bionic 2 Review, Hoka Clifton Review, Saucony Virrata 2 Review, Brooks PureCadence 3 Review, Brooks PureConnect 3 Review, Brooks PureFlow 3 Review, Skechers GO Bionic 2 Review, New Balance 980 Review, Brooks Transcend 2 Review, Hoka Huaka Review, Patagonia EVERlong Review, Asics 33-DFA Review, Hoka Conquest Review, Saucony Cortana Review, Puma Faas 100 R Review, Saucony Fastwitch Review, Nike Free Review, Asics Gel Lyte 33 Review, Skechers GOmeb Speed Review, Skechers GOrun Ultra Road Review, Nike LunaRacer Review, Altra Paradigm Review.