If you're a semi-competitive runner who follows the professional sport, you've undoubtedly heard about the Nike Vaporfly 4% Flyknit Running Shoe ($250). Eliud Kipchoge wore them when he set the world record at the Berlin Marathon last year, Shalane Flanagan wore them during her historic New York City Marathon win in 2017, and now, countless "regular" runners are flocking to buy them, too. I got my own pricey pair in the weeks leading up to a marathon earlier this year.
The Nike Vaporfly 4% was first introduced in 2017 during Nike's Breaking2 project, in which three runners attempted to break the two-hour marathon barrier. A Nike-funded study published in the journal Sports Medicine found that the shoe improved male runners' efficiency by 4 percent on average. (Hence the name.) More studies followed that weren't funded by Nike. One found that the shoe made both men and women more efficient runners. Another helped to identify the mechanisms at work. The researchers found that the shoe's ZoomX foam midsole helped to absorb and return energy, while the carbon-fiber plate stabilized the joints in the foot and improved the mechanics of the ankle. I was intrigued, especially since I hadn't set a personal record in three years, despite dedicating the time to training every year for nearly a decade.
I ran the race of my life in these shoes, bringing my personal best down by four minutes.
I rarely spend more than $100 on new running shoes and had never spent $250 on any shoes, period. But my training season for the Houston Marathon was nearly finished, and I wasn't feeling as confident or race-ready as I normally would at that point. I'd also been devoted to a single brand of running shoes for years, and the latest models weren't really working for me during training runs. Since I hadn't spent as much on new gear or race fees that season, I gave myself permission to splurge. At that point, what did I have to lose?
I ran the race of my life in these shoes, bringing my personal best down from 3:49:44 to 3:45:41. While four minutes might not look like much on paper (it's only a 1.74 percent improvement, after all), it was my strongest marathon performance to date, and I ran the second half of the race two and a half minutes faster than the first. Running a negative split was huge for me, as I had always fallen apart in the last part of the Houston Marathon, where the course turns to rolling hills. More importantly, I felt good all the way to end of those 26.2 miles, and that alone was worth it.
While I've already snatched up another pair to stash away for next year's marathon, I wouldn't completely credit my performance to the shoes alone. I had beautiful weather that day and a relatively flat course, and I had put in the time training. But if, like me, you're hopeful that they could help you up your game, here are a few things to keep in mind before giving them a try.
1. You'll Likely Get Less Than 200 Miles Out of Them
I had heard that the soles of the Nike Vaporfly 4% tend to wear down and lose their bounce after about 200 miles, compared to 500 or 600 miles on most standard pairs of running shoes. I've got about 130 miles on my first pair at this point, and they're definitely getting there. I didn't want this to happen before the marathon, so I ran in the shoes only four times before race day and never further than 10 miles. Normally, I'd run in my race shoes for at least a full month beforehand, including one 20-miler to ensure to ensure they're comfortable. Instead, I broke in the 4% sneakers during my taper period, running in them for my remaining speed workouts and one last long run (a 10-miler at marathon goal pace, which felt almost effortless).
2. You'll Need to Go Up at Least One Half-Size and Maybe More
Nike's Flyknit technology is more form-fitting than other shoes. I typically wear a size 9 in everyday shoes, and a 9.5 in running shoes, so I went up to a 10 when placing my order. Although my feet felt fine throughout the race, I had a huge blood blister under one of my big toenails afterward, and — stop here if you're squeamish — completely lost that toenail about a month later. So, I decided go up another half-size when ordering my second pair. Because the shoes only come in men's sizes, you'll need to subtract 1.5 from your size in women's shoes to find the equivalent in men's (my shoes were a size 8.5, which is the same as a women's 10).
3. You Still Have to Train as You Usually Would
At the end of the day, the training I put in dictated my race. I run year-round, ramping up from 30 miles per week to 50 miles during a marathon training cycle, with my longest run going up to 22 miles. If I had missed some training runs and workouts due to injury or illness, I'm certain that I would have blown up on race day. Put in the work, then put the sneakers to the test.