Rating the Most Popular Speed Training Shoes on Comfort, Speed, Durability, Traction, Bounce, Weight, Fun Factor and Value
Here we will break down the comfort, speed, stability, durability, traction, bounce, weight, fun factor, and overall value of the most popular speed training shoes currently on the market—the Saucony Endorphin Speed 5, Adidas Boston 13, Nike Zoom Fly 6, and the Hoka Mach X2.
Welcome back to Choose Your Player. In this series, we’re giving running shoes an overall score based on 10 key categories—ranging from pure speed to all-day comfort—each rated from 1 to 100. This time, we’re taking a closer look at the stats on the top speed trainers hitting the road.
Comfort
If we’re not going full Carbon County with a race-day shoe for a workout or speed session, we at least expect to gain a little comfort at the expense of demon-time speed. The Endorphin Speed 5 takes the top spot here thanks to its lightweight, breathable upper and pleasant step-in feel. Next up are the Boston 13 and Mach X2, with the Boston offering a much-improved upper over the previous version and both delivering smooth, comfortable ride experiences. The Zoom Fly 6, while equipped with a nice upper, loses points due to its harsh, uncomfortable ride caused by the high plate placement.
Nike Zoom Fly 6
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Speed
The Boston 13 takes the win in this category. Its dual-foam setup with a top layer of Lightstrike Pro and glass fiber rods gives it a serious speed advantage. The Mach X2 is close behind—it really shines for long runs and up-tempo sessions. While the Speed 5 uses an older PEBA foam and a nylon plate, its light weight and efficient geometry make it easy to pick up the pace. The Zoom Fly 6 comes in last. While Nike labels says the foam is ZoomX, it doesn't resemble the responsive ZoomX in the Vaporfly or Alphafly.
Stability
Stability matters in a speed trainer, especially since you’re typically sacrificing some of the speed assistance found in a less stable race-day shoes. The Boston 13 stands out as the most stable of the bunch—it has a grounded feel, a less rockered geometry, and a lower stack height. The Mach X2 also performs well here. If you need stability, the Speed 5 and Zoom Fly 6 are likely not the best picks.
Adidas Boston 13
Durability
Durability is another important factor in a speed training shoe. One reason many people have speed training shoes in their rotation is to save their less-durable race shoes for key workouts and race day. The Boston 13 has a strong track record, and after 100 miles we saw almost no wear on the outsole or loss of foam pop. The Mach X2 also looks promising in this regard, with its foam holding up well to high mileage. The Endorphin Speed 5, like earlier versions, seems to lose pop around the 250-mile mark. The Zoom Fly 6 starts off feeling flat and doesn’t age well—its version of ZoomX lacks energy return so we don't expect it to hold up well over time.
Traction
With its Continental rubber outsole, the Boston 13 dominates this category. It grips well on slick and wet surfaces. The Speed 5, Zoom Fly 6, and Mach X2 all offer adequate traction, but none match the Boston’s performance here.
Bounce
The Mach X2 and Speed 5 offer a nicely tuned, controlled bounce—enough to keep things feeling lively without going full trampoline mode, like in the new Adidas Prime X 3 Strung. The Boston 13 offers more of a responsive, planted ride that requires you to put in some work. The Zoom Fly 6, again, disappoints. Its foam lacks the energy return of true ZoomX, leaving it flat and uninspiring.
Hoka Mach X2
Weight
There’s not a significant difference in actual or perceived weight among these four shoes. Weight alone likely won’t be a deciding factor between them.
Fun Factor
The Speed 5 tops our list here—it’s light, lively, and just fun to run in. The Mach X2 isn’t far behind, delivering a smooth and enjoyable ride. The Boston 13 is more of a blue-collar workhorse—reliable but not overly exciting. The Zoom Fly 6 brings up the rear, as we didn’t enjoy the ride at any pace.
Saucony Endorphin Speed 5
Value
At $160, the Boston 13 is the best bang for your buck. It’s versatile enough for daily miles, speed workouts, and long runs. The Mach X2 retails for $190, which makes it pricier, but it still performs well for speed sessions and long runs, alike. The Speed 5, at $175, is a bit less durable and doesn’t offer quite the same value as the other two. The Zoom Fly 6, at $180, is overpriced in our opinion—it doesn’t handle high mileage well and was uncomfortable at both speed and recovery paces. It’s earned the nickname “Gloom Fly Bricks” here at Supwell.
Final Thoughts
Each shoe brings something unique to the game—from the fun and bounce of the Endorphin Speed 5 to the reliability and long run capabilities of the Mach X2, the sheer speed of the Boston 13 and the drip factor of the Zoom Fly 6. Choose your player wisely—your enjoyment of your workouts and speed sessions might depend on it.
Check out our Choose Your Player Marathon Racing Shoes edition or Choose Your Player Max Cushion Shoes if you've enjoyed this format.
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