Physical Therapists Using Clinical Analysis To Discuss The Art And Science Behind Running and The Stuff We Put On Our Feet

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Topo Cyclone 2

Topo Athletic is a brand that's quietly grown since its inception in 2013. Known for their low drop, wider fitting footwear, they've garnered a following for their comfort. In recent years, they've also been expanding their line into the performance trainer forum, releasing some exciting new shoes that have elevated the brand into the future. With their focus on fit, natural running shoes to "move better," and newfound interest in competitive midsole foams, it's an exciting time to get to know Topo.

Guide to Topo Athletic Running Shoes
Written and Edited by Content Manager Bach Pham

About Topo Athletic

Founder Tony Post. Photo courtesy of Topo Athletics
"Minimal" beginnings. Topo Athletic was founded by Tony Post a 30-year industry veteran in running best known for his work with the Vibram five fingers that took the world by storm during the minimalist movement. After the success of five fingers and knowledge learned, Tony wanted to move on to new projects and decided to leave Vibram to explore his interests. In 2013, he and a small team launched Topo Athletic (based on the first two letters of his first and last name; also a nickname Tony had in college). "With Topo I wanted to take some of those natural ingredients we learned from Vibram five fingers and also some of the things we learned that wasn't so good, and bring that into a brand people could use without the stigma of the five toes, but have some of the benefits that I thought would be a natural running product," Tony explained to us in a conversation on our podcast in 2022.

Our interview with Topo Athletic Founder Tony Post. You can also listen to this episode on the run.

Natural Runners.
In many ways, Topo Athletic is a merger of the natural running that Tony Post came to know well with his work at Vibram along with his desire to bring well-fitting shoes into the market that accommodates a wide number of runners. The combination of ample toe boxes and secure midfoot and heels has been a signature of the brand that sets them apart from most running brands today.

Elite Ultra Runners. Topo's Elite team is fielded primarily of ultrarunners like Boulder, Colorado-based Anthony Lee and Albuquerque, New Mexico-based Andrea McArdle. They also sponsor triathletes, including veteran and 19 time Ironman race winner Angela Neath. Learn more about their athletes here.

Technology to Know

"Anatomical toe box
." Topo's signature feature is their wide toe box which aims to help provide ample room for toe splay.

Lower drop.
Most of Topo's footwear sits anywhere from zero drop to 5mm. Most of their performance footwear come in at 5mm. For more on drop, check out our shoe science post on Instagram to learn more.

ZipFoam. Topo's signature EVA blend that incorporates thermal plastic material to make it a bit springier than just regular EVA. Topo states it to be more durable than EVA by 25% and not sensitive to cold/warm conditions.

PEBAX-powered. New to Topo in 2022, the brand introduced a brand new performance line with the Specter and Cyclone, each featuring PEBAX in the midsole in some capacity.

Science Feature: The Importance of Room
for Foot Splay
By Andrea Myers

Many scientific articles have been written regarding the effect of 0 drop shoes on various injuries. Less has been written regarding a common feature of 0 drop shoes, which is a wide, “foot-shaped” toe box. Besides the obvious (your shoe should be shaped like your foot, not squeeze your toes together), what does the scientific literature say about the benefits of a wide toe box?

Researchers at Brigham Young University evaluated the effect of passive hallux adduction (pushing the big toe outwards, towards the other toes) on blood flow in the lateral plantar artery. They hypothesized that this positioning would result in decreased blood flow in the artery, which supplies the plantar fascia. They proposed that the abductor hallucis muscle may play a role in this arterial compression. The abductor hallucis runs along the medial aspect of the foot and moves the big toe away from the second toe. Putting the abductor hallucis in a lengthened position may compress the posterior tibial artery, which feeds the lateral plantar artery. Evidence is emerging that the persistent nature of plantar fasciitis may be a result of decreased blood flow to the plantar fascia, which slows healing. Poor fitting running shoes that are too narrow across the forefoot could cause passive hallux adduction and could be a contributing factor to the development and persistence of plantar fasciitis.

The researchers used ultrasound to quantify blood flow and vessel diameter in the lateral plantar artery with the foot in a resting position and with the big toe pushed towards the other toes (hallux adduction). They found a statistically significant decrease in blood flow and artery diameter during passive hallux adduction. They also found that the decrease in blood flow was greatest in subjects with pes planus (low arch), which they theorized was due to lengthening of the abductor hallucis muscle in flat footed individuals. The role of reduced blood flow in the development of plantar fasciitis needs further research, but the preliminary evidence suggests that narrow footwear could reduce blood flow in the lateral plantar artery.

The take home message here is that regardless of drop, shoes should be wide enough at the toe box to allow for normal toe splay. A simple way for runners to test if their shoes are too narrow is to remove the shoe insert and stand on them. If the foot is wider than the insert, the shoes may be too narrow.


Jacobs, J.L., Ridge, S.T., Bruening, D.A. et al. Passive hallux adduction decreases lateral plantar artery blood flow: a preliminary study of the potential influence of narrow toe box shoes. J Foot Ankle Res 12, 50 (2019).

Breaking Down the Topo Athletic Running Line

Topo Athletic features a slim and simple line. The biggest differences to take note are the various drops, which we indicate below. To learn more about each shoe, click the shoe title to find our review of the latest model.

Neutral Topo Running Shoes
Phantom 3
(daily trainer) - Their basic everyday trainer. Featuring a 5mm drop that's meant to introduce runners to the brand. Features their signature ZipFoam and a fantastic new updated fit.
Magnifly 5 (zero drop daily trainer) - Their moderate cushion option, the Magnifly is well-fitting, zero drop trainer at 25mm of stack height throughout.
Topo Cyclone 2 (performance trainer) - Featuring a full-length PEBAX midsole, this lightweight, 5mm drop trainer is springy and fun for a variety of runs and workouts. Features a less rockered, more flexible ride.
Specter (performance trainer) - Featuring a PEBAX core with ZipFoam carrier, this is more rockered and rigid than the Cyclone. Also features a 5mm drop.
ST-4 (minimalist zero-drop trainer/crosstrainer) - The ST-4 an extremely low profile, zero drop everyday trainer for running and gym workouts.

Stability Shoes from Topo Running
Ultrafly 5 (moderate cushioned stability trainer) - The Ultrafly 5 is uniquely one of the only low-drop (5mm), medial stability shoes in the market.

Trail Shoes from Topo Running
Ultraventure 3 (standard trail trainer) - A nicely cushioned, traditional ride with a 5mm drop, the Ultraventure is a solid easy/long run trail shoe for everyday training.
MTN Racer 3 (mild stability trail shoe) - The Topo MTN Racer 3 is a moderate to high stack height trail performance/racing shoe with a minor medial stability piece which is rare in trail footwear.
MT-5 (hybrid trail trainer) - A moderately cushioned trail runner that can go on road and get you where you need to be. Also a solid hiker.

Topo MTN Racer 2
Our Topo Recommendations to Try

I want a comfortable trainer with a great fit: Phantom 3
(We can't get over how good the shoe fits. Mild ride handles easy days well)

I want a solid zero drop trainer: Magnifly 5
(Great fitting, pleasant zero drop trainer)

I want the best Topo shoe with all the goods: Cyclone 2

(The Cyclone provides a fast, lightweight trainer that can tackle daily training and workouts with its impressive nonplated PEBAX midsole)

One of the few low drop, medial stability shoes in the market:
Ultrafly 5
(There are low drop stability shoes, but few that tackle medial stability as forward as the Ultrafly)

Have questions? Send us an email at

Thanks for reading!

More Shoe Brand Guides


Running Shoe Resources
Looking for something more specific than the archive? Check out these pages first:

Beginner's Guide to Running Shoes: Are you a brand new runner and unsure where to start? Visit this guide first to get started.
Stability Shoe Resource Page: Our comprehensive guide to stability shoes and alternatives for neutral runners as well
Carbon Fiber Plated Shoes Resource Page: Want to go as fast as possible for race day? Visit this page for all of our super shoe reviews
Guide to Walking Shoes: Featuring some science behind walking and the best running shoes for walking based on our everyday testing and clinical experience working with patients.
Getting the Right Fit: Unsure if your shoe fits? Visit this page to help you determine how to find the right shoe for your feet. Comfort is one of the most important things we emphasize at Doctors of Running before you get out the door and on the road. Sometimes the right shoe for you is not what works for many others. That is why it is important to try different shoes when you can to get a better understanding of works best for your needs.
Beginner's Guide to Nutrition/Hydration: Guest writer Jennifer Giles (Registered Dietitan/Nutritionist) helps bring a new guide for fueling to Doctors of Running as part of our summer hydration series.
Ultimate Guide to Hydration Products for Runners: We review 10+ hydration products that may help you on your running adventure.
Best Affordable Running Shoes: We compiled a list of the most affordable options you can find in the market today. Updated monthly.

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