Comfort is the best reason to buy technical running shoes. Wearers find different things comfortable. For many, a comfortable sneaker has plenty of room to accommodate the length, width, and height of the foot. Others find relatively large amounts of cushioning to be comfortable. Some think that sneakers that allow the wearer to feel the ground are most comfortable. Most people are comfortable in sneakers with a heel. But there are some that find the opposite feature—which is a completely flat shoe—to be the most comfortable. Flat shoes are sometimes called zero-drop sneakers.

Zero-drop doesn’t work for some

In our experience, it’s hard to predict who will like zero-drop sneakers. But we can predict who won’t like them: people with tight heel cords. Tight ankles will be constantly stretched if they are put into zero-drop sneakers.

Walking, running, and doing whatever else you do in shoes can be uncomfortable if the Achilles tendons are being stretched the entire time. The ankles might adapt by growing chronically longer. But that may not happen, and even if it does, there may be an uncomfortable period of time before that adaptation occurs.

What is drop?

The drop is the height of the heel in a shoe. The feature has been seen in shoes for about 45 years. I gave this explanation, in an earlier post, for why manufacturers started putting heels in technical running shoes:

“It’s helpful to remember that track athletes and road racers were the key—perhaps the only—demographic for running shoes. They were demanding customers because they did demanding things in their shoes.

Those runners were racing Marathons, not just participating in Marathons. They would train, not just run recreationally. These folks were accustomed to running many miles in their shoes, every week.

So the shoes had to be comfortable. At the very least, they couldn’t be so painful that they interfered with training and racing. So, those runners gave manufacturers a lot of feedback. And when the runners complained about ankle pains, manufacturers concluded that a heel in the shoe was called for.

When the manufacturers then noticed that heel-area pain complaints were reduced—especially when Achilles tendon injuries were reduced—they took that as confirmation that the heel helped.”