Home » How Should Your Cross-Training Shoes Fit? Cross-Training Shoe Size Guide

How Should Your Cross-Training Shoes Fit? Cross-Training Shoe Size Guide

One of the most common questions I get asked on all of my cross-training shoe content is, “How does this model fit?” Sizing is quite possibly one of the toughest aspects to get right when shopping for new models. Plus, the last thing anyone wants to do is purchase a poor-fitting cross-training shoe.

As a cross-training shoe reviewer, it’s sometimes difficult to help others nail their sizing due to the sheer amount of differences that exist between all of our feet’ anatomy. For example, we have lifters with wider feet and others with high arches, all of these foot differences will influence how a shoe will fit.

To help you out, I wanted to put together a cross-training shoe sizing guide. This guide is intended to help suggest my sizing thoughts for a variety of cross-training shoes in 2021.

How Should Cross-Training Shoes Fit?

In general, you’ll want your cross-training shoes to have anywhere from .2″-.6″ of room at the end of your shoe’s toe box. This length is usually snug enough to prevent heel slip and not too tight to where your feet are cramping during workouts.

how should cross training shoes fit (1)

In addition to the above, when we consider cross-training workouts and the activities they include, we can better direct how we want our shoes to fit. For example, let’s say you’re primarily using your shoes to tackle plyometrics and HIIT workouts. This style of training will involve a lot of movements that have forward momentum.

If your shoes are too tight or too loose, then you can run into the issues of cramping and sliding around mid-workout. The last thing you want is your foot sliding around during something like a box jump.

In this context, a cross-training shoe that has around .4″ of room in the toe box would likely be a good option for a majority of athletes and lifters. Remember, when considering your ideal cross-training shoe size, consider how you actually train and what is most comfortable per your foot’s anatomy.

Cross-Training Shoe Sizing Guide

On my YouTube channel and on That Fit Friend, I always try to provide my sizing thoughts for the cross-training shoes that I review. If you’re interested in checking out how top shoes for certain categories compare to one another with sizing thoughts, then I’d highly suggest checking out my best cross-training shoe article and video.


Below, you’ll find every recent cross-training shoe that I’ve reviewed along with my sizing thoughts. For the record, I’m a size 10 with a “neutral” foot in regard to width.

Reebok Cross-Training Shoe Size Guide

  • Reebok Nano 8: True-to-Size (wider width)
  • Reebok Nano 9: True-to-Size
  • Reebok Nano X: True-to-Size
  • Reebok Nano X1: True-to-Size
  • Reebok Nano X1 Froning: True-to-Size, but slightly long in the toe box.
  • Reebok Nano X1: Adventure: True-to-Size
  • Reebok Speed TR: True-to-Size, but more narrow last. Not a great option for wider feet.
  • Reebok Nanoflex TR: True-to-Size
  • Reebok Flashfilm Train 2.0: True-to-Size

Nike Cross-Training Shoe Size Guide

  • Nike Metcon 5: True-to-Size, but more narrow last. Not a great option for wider feet.
  • Nike Metcon 6: True-to-Size, but more narrow last. Not a great option for wider feet.
  • Nike Metcon 7: True-to-Size, but more narrow last. Not a great option for wider feet.
  • Nike Free Metcon 4: True-to-Size, but fits more narrow.
  • Nike React Metcon Turbo: True-to-Size.

Under Armour Cross-Training Shoe Size Guide

  • UA TriBase Reign 2: True-to-Size, runs a tad more neutral.
  • UA TriBase Reign 3: True-to-Size, runs a tad more neutral.
  • UA HOVR Rise 2: True-to-Size
  • UA HOVR Rise 3: True-to-Size
  • UA HOVR Apex 3: True-to-Size
  • UA Project Rock 3: Runs small, size up .5-1 size.

Inov-8 Cross-Training Shoe Size Guide

  • Inov-8 F-Lite 235 V3: True-to-Size, but runs a bit more narrow.
  • Inov-8 F-Lite G 300: True-to-Size
  • Inov-8 F-Lite 245: True-to-Size

On Cross-Training Shoe Size Guide

  • On Cloud X: True-to-Size

NOBULL Cross-Training Shoe Size Guide

  • NOBULL Trainers: True-to-Size
  • NOBULL High-Top Trainers: True-to-Size, but you may want to size up a half size if you generally feel cramped in your normal true-to-size models.

GORUCK Cross-Training Shoe Size Guide

  • GORUCK Ballistic Trainers: True-to-Size

I Have a Wide Foot, Should I Size Up?

That depends. If you have a wider foot, then sizing up in certain models can lead to heel slip and actually hinder how a shoe fits you. When companies create cross-training shoes, they select a last (mold) that is, in theory, going to fit the grandest audience.

At times, the last a company selects to use may not align with your foot’s anatomy. A classic cross-training shoe example of this is how wider footed individuals often find Nike Metcons super uncomfortable, but enjoy shoes like Reebok Nanos.

In this example, the lasts that Nike and Reebok use are more narrow/neutral and slightly wider, respectively, which is why one might not align with your foot’s anatomy and the other does not. If you have a wider foot, then something like a Nike Metcon may never fit you perfectly.

Instead of sizing up, I’d suggest looking at other cross-training shoe options that have lasts that align with your foot’s anatomy better.

What Is Heel Slip?

Heel slip is a term used to describe what happens when the heel slips out of a shoe’s boot when exercising. Heel slip can occur when walking, jumping, lifting, and really during any movement that causes ankle dorsiflexion, AKA a movement pattern that can cause the heel to slip out of a shoe’s boot.

what is heel slip

Heel slip generally occurs when there’s excessive room in one’s shoe. If there’s too much room in the toe box, then heel slip can occur when the foot slides up during exercise. Conversely, if there’s too much room in the boot, then the heel can slip out during even the most casual movements like walking.

How Much Room Should I Have In the Toe Box?

A shoe’s tox box will vary with its width and what is ideal for you will depend on the anatomy of your foot. Wider toe boxes will accommodate greater toe splay. Toe splay is the act of spreading the toes out to increase the surface area of the foot to improve stability and balance when training.

For context, if you have a more narrow foot, then you can wear a wider variety of cross-training shoes. However, for my wider footed friends, you’ll be limited in which shoes fit best due to more narrow and neutral shoes feeling super tight in the toe box.

The ideal toe box will give you enough room to splay the toes when training, but not squeeze the lateral and medial toes too much. If you’re leaving training sessions with blisters on your pinky toe or big toe, then you likely should explore different shoes with wider toe boxes.

How to Measure Your Shoe Size At Home

If you’re interested in measuring your shoe size at home, there are a few simple ways to do so. To keep things simple, we’ll break this process into three steps.

Step 1: Grab a Piece of Paper, Pencil, and a Ruler

The first step is grabbing a piece of paper, a pencil, and a ruler. You’re then going to place your foot on the piece of paper and either 1) trace your foot, or 2) make a mark at the very end of the heel and your longest toe.

how to measure foot size at home

Step 2: Measure the Recorded Length

Once you’ve traced your foot or recorded its maximal points to determine its length, you’ll then measure your foot. You can also measure the width of your foot if you traced it to compare your foot’s width to some companies sizing charts if they provide a metric for establishing a shoe’s width.

With this measurement, you’ll then relate this measurement(s) to step 3 below.

Step 3: Compare Your Measurements With the Size Charts Below

Once you have your foot’s length, you’ll then compare it to the chart below to establish what size shoe you should be looking into. This can be really useful because some companies have their own sizing charts.

So, in the event a company has a more proprietary sizing system, then you can get a more accurate gauge for the shoe size that would fit your needs best.

Men’s Shoe Sizing Chart

For the men’s general shoe sizing chart in US and UK sizes, check out the graphic below.

men's cross-training shoe sizing guide

Women’s Shoe Sizing Chart

For the ladies, check out your sizing chart below for general US and UK shoe sizes.

womens shoe sizing guide

Outside of the above information, if you want the most accurate shoe size measurements, then I’d suggest visiting a shoe store where they can more accurately provide you with the dimensions of your foot.

In some cases, lifters, and athletes wear the wrong size shoes which can lead to models never feeling like they fit “perfect”. When in doubt, I’d suggest seeking out professionals in your area to go visit physically to get your most accurate foot measurements.

Takeaway Thoughts

In the vast cross-training shoe market, shoe sizing can be seriously confusing at times. With everyone’s anatomical differences, it’s impossible to create blanket statements that a shoe will fit everyone. This is why it’s important to acknowledge your individuality, then make shoe choices that actually align with your foot’s size.

If you have any questions on cross-training shoe sizing or need further assistance in regard to specific models, drop a comment below or reach out to me personally via Instagram (@jake_boly).


Jake Boly

I've been in the fitness and strength training industry for nearly a decade. In that time, I've trained hundreds of clients, created thousands of articles, reviewed countless products, and produced a large list of training videos. And truthfully, I'm only getting started! As for my educational background, I have my Masters in Sports Science, Bachelors in Exercise Science, and have my CSCS.

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