Ask a Trainer: Should I Wear Racing Flats For the Marathon?

Can they save you a few a seconds, or even minutes, on race day or will wearing them make you more susceptible to injury? Mario Fraioli weighs in!

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I am running my first marathon this spring, and have a footwear question. Should I wear racing flats for the race, or stick to my training shoes? I’ve worn racing flats for 5K and 10K races, but never for anything longer than that. My goal is to break 3:30. What should I do?


James W., Newmarket, NH



I got this question all the time when I worked in the specialty running industry. Racing flats, while sleek, bright and slipper-like, just aren’t for everyone when it comes time to line up for a marathon. But who are they for?

Faster runners

Take a look at the runners on the starting line of any major marathon and they will all be wearing racing flats that weigh in well under 10 ounces. For these faster runners, every second counts. Of course, this begs the inevitable question, “Well, who classifies as a faster runner?” While there’s no easy or absolute answer to this question, I draw the line at 3 hours and 30 minutes. This isn’t meant to sound elitist, but studies have shown that after 3 hours of running (and in most cases, well before this point) fatigue sets in and mechanics will inevitably start to fail. Racing flats will offer little in the form of protection when your form starts falling apart, thus opening you up to the possibility of injury. In the end, you’ll end up losing more time than you gain from having a lot less shoe on your foot.

EEI’s, or Experienced, Efficient, Injury-free runners

Faster runners tend to be the most efficient runners and their support needs in a shoe when running at race pace aren’t as great as those in the back of the pack. Does that mean racing flats should be limited to runners the first few corrals? Not necessarily. If you’ve been running a while, your legs aren’t all over the place when your rolling down the road and you have a relatively incident-free injury history, then it might not cause you too much harm to give racing flats a shot. How do you know if you’re efficient? Visit your local specialty running store, try on some racing flats and have an experienced professional give you some honest feedback if you aren’t sure. If you typically train in a lightweight shoe or racing flat anyway, then by all means consider wearing them for your marathon, providing you’ve got through a few of your key long runs without experiencing any injury issues. If you’re a new runner, have been cursed with poor mechanics, or have a history of overuse injuries, however, stick to your trainers for now. Or try a lightweight performance, which will offer you a little bit more protection than a racing flat, while still being lighter than your heavier training shoes.

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In your case, James, given the fact that you’re aiming to run under 3:30 and have experience wearing racing flats at shorter distances, I believe you can safely consider wearing racing flats for your race in May. Since you’ve got some time on your side, I would recommend doing at least one of your key workouts or long runs in your racing flats every week over the next three months. Of course, moderation, adaptation and progression are key to a successful (e.g. injury free) transition, so be careful not to do too much, too soon. Start using them during some easy runs, then try them in a track workout or other key workout and eventually a longer marathon-paced tempo run or two.

Best of luck!


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