纽约时报｜应该多久更换一次跑鞋？

有趣灵魂说

跑鞋穿多久该换？300到500英里是常见标准，但专家说：别只看里程。鞋底压痕、失去弹性、脚感“死板”都是信号。磨损的鞋子可能悄悄改变你的跑姿，增加受伤风险。如果你感觉不到明显变化，不妨试穿一双同款新鞋对比一下。舒适诚可贵，但该换就换——别等脚疼了才后悔。

译文为原创，仅供个人学习使用

The New York Times ｜ ASK WELL

纽约时报｜问问专家

How Often Should I Replace My Running Shoes?

我应该多久更换一次跑鞋？

These are the signs it’s time for a new pair.

以下是需要换新鞋的迹象。

By Allessandra DiCorato

Eric Helgas for The New York Times

关于跑鞋的使用寿命，我听过很多不同的说法。我怎样才能知道什么时候该换新鞋了？

一旦找到了合脚的那双跑鞋，就很难舍弃它。一个经常被引用的经验法则是，在跑了大约 300 到 500 英里（约 480 到 800 公里）后，就应该更换跑鞋。但对于坚持跑步的人来说，如此频繁地购买新鞋，费用会迅速累积。而且，研究人员仍未完全理解穿破旧的跑鞋跑步会如何导致受伤，部分原因是，一些实验室测试并不能很好地还原鞋子在日常生活中的实际穿着表现。

印第安纳大学伯明顿分校运动机能学副教授艾莉森·格鲁伯表示，研究并未指出一个对每个人都导致受伤的单一里程数。但她补充说，大多数跑步生物力学专家都会同意“存在一个需要换鞋的临界点，而你应该在感到不适之前就换掉它”。

我们询问了专家，是什么决定了跑鞋的磨损速度，以及如何知道何时需要更换。

是什么造成了磨损

亚当·滕福德博士（一位运动医学医生，也是斯波尔丁国家跑步中心的跑步医学主任）说，许多因素都会改变鞋子的磨损方式，包括鞋子的使用年限、你的体重、你跑步的地面，甚至你跑步环境的湿度和温度。穿着跑鞋去健身房或办事也会加速其磨损。

有些鞋子比其他鞋子磨损得更快。俄勒冈州立大学卡斯卡德斯校区生物力学研究员兼助理教授 JJ·汉尼根说，现代“超级跑鞋”是为比赛而设计的，包含一层厚实的轻质泡沫，虽然有利于性能表现，但通常比普通训练鞋中的泡沫材料分解得更快。

穿着旧跑鞋跑步会怎样

即使你觉得旧鞋穿着舒服，让它们退役仍然可能有好处。一些研究表明，磨损会减少鞋子的缓冲，给双脚带来更大压力，一些科学家认为这可能会增加受伤风险。

一项研究分析了参与者在鞋子全新时以及跑了 200 英里（约 320 公里）后的跑步姿态，发现在后续测试中，跑者的动作发生了微小变化。格鲁伯博士说，虽然专家们不知道这些变化是否足以直接导致严重损伤，但它们可能会降低跑步的舒适度，并导致你调整步态，从而可能为未来的受伤埋下隐患。

需要换鞋的迹象

可见的磨损是显而易见的信号，表明你需要一双新鞋了。你可能会注意到鞋面和鞋底之间的泡沫层看起来更加皱缩、被压得更紧实。汉尼根博士说，你还可能看到提供抓地力的鞋底区域出现磨损，尤其是专为越野跑设计的鞋子。根据你跑步时脚是内旋还是外旋，鞋底可能会出现不对称的磨损。如果你脚比较宽，脚趾可能会开始从鞋面部分戳出来。

许多经验丰富的跑者也表示，他们能感觉到什么时候鞋子该换了。纽约市的跑者、教练兼物理治疗师布伦丹·马丁说，当他的鞋子开始感觉有点“死板”或失去弹性和舒适感时，他就能注意到。

滕福德博士说，每跑 300 到 500 英里（约 480 到 800 公里）换一次鞋的标准建议，是一个很好的通用指南。（一些跑步应用程序，如 Strava 或 Nike Run Club，可以帮助你记录里程。）但如果你的鞋子感觉缓冲仍在，没有明显的磨损，而且你也没有感到任何疼痛，那么你很可能还可以再用久一点。但汉尼根博士提醒说，请记住你自己的感觉可能并不完美。

为了解决这个问题，你可以试穿一双同款的全新鞋子，感受一下它们有多不一样，或者将你的鞋子与刚买时的照片进行对比。马丁博士说，如果你仍然不确定，物理治疗师或专业跑步用品店的员工可以帮助你发现鞋子随着时间推移而产生的细微变化，这些变化是日积月累、不易察觉的。

“这就像你的头发，”他说，“你每天都在镜子里看到它，所以你不会意识到它已经变得有点长和凌乱了，直到有人指出你需要理发了。”◾

Q: I’ve heard a lot of different things about how long running shoes should last. How do I know when it’s time for a new pair?

Once you find the right pair of running shoes, it can be hard to part with them. It’s a frequently cited rule of thumb that you should replace your running shoes after you’ve run about 300 to 500 miles in them. But buying a new pair that often can add up quickly for consistent runners. And researchers still don’t fully understand how running in worn-out shoes may contribute to injuries, in part because some lab-based tests don’t do a great job of replicating how shoes perform on your foot in everyday life.

Research doesn’t point to a single number of miles that leads to injury for everyone, said Allison Gruber, an associate professor of kinesiology at Indiana University-Bloomington. But, she added, most experts in running biomechanics would agree “that there is a point where you need to change your shoes, and you want to do that before you’re uncomfortable.”

We asked experts about what determines how quickly your running shoes wear out, and how to know when it’s time to replace them.

What causes wear and tear

Many factors can change how your shoes wear, including how old they are, your body weight, the surfaces you run on and even the humidity and temperature of your running environment, said Dr. Adam Tenforde, a sports medicine physician and the director of running medicine for the Spaulding National Running Center. Using your running shoes for trips to the gym or for errands will also wear them out more quickly.

Some shoes degrade more quickly than others. Modern “super shoes,” designed for racing, contain a thick layer of lightweight foam that is good for performance but typically breaks down more quickly than the foams in a regular training shoe, said JJ Hannigan, a biomechanics researcher and assistant professor at Oregon State University-Cascades.

What happens if you run in worn-out shoes

Even if you find your old shoes comfortable, there can still be advantages to retiring them. Some research suggests that wear decreases cushioning in shoes and puts more pressure on your feet, which some scientists think could increase your risk of injury.

One study analyzed how participants ran in shoes when they were new and after 200 miles and found small changes in how the runners moved during the later test. While experts don’t know whether those changes are enough to directly cause significant injury, Dr. Gruber said, they could make running less comfortable and cause you to adjust your stride in a way that might lead to injury down the line.

Signs you should replace your shoes

Visible wear and tear can be an obvious indication that you need a new pair of shoes. You might notice that the foam layer between the upper and the bottom parts of the shoe appears more wrinkled and compressed. You may also see wear on the areas of the shoe that provide traction, particularly in footwear designed for trail running, Dr. Hannigan said. Depending on whether your feet roll inward or outward when you run, the bottom of your shoes can break down asymmetrically. And if you have wide feet, your toes might start to poke through the upper part of your shoe.

Many experienced runners also say they can feel when their shoes need replacing. Brendan Martin, a runner, coach and physical therapist in New York City, said he notices when his shoes start to feel a little “dead” or less bouncy and comfortable.

The standard advice to replace shoes every 300 to 500 miles can be a good general guideline, Dr. Tenforde said. (Some running apps, like Strava or Nike Run Club, can help you keep track.) But if your shoes still feel cushioned, you don’t notice visible wear and you aren’t experiencing any pain, you can most likely use them a little longer. But remember your perception can be imperfect, Dr. Hannigan said.

To help combat that, you can try on a fresh pair of the same shoes and see how different they feel, or compare your shoes with photos of when they were new. If you’re still not sure, Dr. Martin said, a physical therapist or the staff at a running specialty store can help you detect subtle changes that develop in your shoes over time, which can sneak up on you.

“It’s like your hair,” he said. “You see it in the mirror every day, so you don’t realize that it’s gotten kind of long and straggly until someone else points out that you need a haircut.”