Our testing has taken us through neighborhoods and down bike paths in South Lake Tahoe, CA; Reno, NV; Seattle, WA; Portland, OR; and San Luis Obispo, CA. We've sought out all manner of terrain. Some days we went out on tracks, while others were about the secluded bike paths.
Cushioning
Underfoot cushion is huge when it comes to comfort. We measure the stack height of each contender at the heel and forefoot after cutting each shoe in half in our testing facility. This gives us the heel-to-toe differential, a major player in how a shoe will ride and what kind of runner it's best for.
This metric is gauged largely by feel. Preferences toward underfoot cushioning are subjective, but the literal amount that each shoe houses is not. We test each shoe's landing comfort by pounding the pavement and noting how each footfall feels. On longer runs, we consider how our joints feel after each distance effort to help us assess.
Upper Comfort
We test upper comfort by surveying the materials used in the upper construction of each shoe. We note the tongue and lace bed style, knowing that shoes made for sprinting are less likely to have super comfortable uppers. We run a lot of miles in each pair of shoes, and we get to know which ones we prefer for long distances and which ones are best worn in short spurts.
The shoes that score the highest in this metric tend to have plush tongues with lace beds that don't dig in. We love an articulated heel collar that offers enough cushion to stay snug and avoid creating heel blisters. Finding the right shoes comes down to personal preference regarding upper comfort. Consider the shape of your toes and what style of toebox will fit you best — some toeboxes aren't quite right for some runners, which is okay! Once you determine your shoe needs, you can decide how much emphasis you want to place on upper comfort.
Stability
Some runners need stability in their running shoes, especially for longer runs and training blocks. Some running shoes are built to be stable and have lateral structures to help runners' gaits stay organized even as they fatigue. Other shoes rely only on their engineered mesh, while others offer less support.
We test for stability on the road by intentionally trying to overpronate as we run and documenting the results. Sometimes, we can feel a shoe's stability, or lack thereof, towards the end of long runs when our tired legs want to get sloppy. Other times, we can feel a lack of structure immediately. Our in-house team takes measurements of the shoes, including width, length, and foam density, to provide a more objective assessment of stability features.
Responsiveness
Responsiveness is a key component of a running shoe that many runners looking to amp up their speed care about. Responsiveness essentially describes the amount of energy return each shoe has. In recent years, the trend has been to pack the midsole with a ton of tech so that runners feel propelled from one footfall into the next. Another aspect of responsiveness is the rocker angle and location. These specs are measured and recorded in our testing facility in Tahoe, and we use the hard data to back up our more subjective evaluation of the underfoot feel of each shoe.
We take into consideration what each shoe is made for. Some are specifically designed to be speedy, while others are better suited for dampening the impact on your joints. We test responsiveness by running at top speed in each pair of shoes. Of course, we do consider the technology included in each pair as we do this, but testing responsiveness is all about the run. Some shoes feel like bricks on your feet, while others feel more like rollers. The more a shoe feels weightless and like it is allowing you to effortlessly roll from one step to the next, the better its responsiveness.
Weight
We test weight in the most obvious way — by weighing each pair on a digital scale at our facility. We weigh everything right out of the box for consistency and determine scores from there based on a formula. We are also careful to note how evenly the weight feels distributed in each pair while running, so we can offer a more personalized experience of how weightless (or bricklike) a shoe feels.
Traction
Beyond observing the lug depth and patterning across each shoe's outsole, we seek out slippery places to gauge each shoe's traction rating. When it comes to road shoes, their outsoles are not all created equal. In general, we find that shoes built for versatility and stability offer stronger traction than those built for speed. No matter what we think we'll find, we hurdle around the same gravel-covered corners in our neighborhoods, take to the roads on rainy days, and try skidding down sandy rocks at the beach. Some shoes excel on dry roads, while others can handle gravel with ease. Consider the type of running you'll be doing before purchasing your next pair, since traction is a huge safety feature.
