I've been a fan of barefoot-style shoes since I first tried them years ago. There is something primal about walking barefoot outside – the sensation is like no other. However, as much as I like the barefoot shoes, I haven't recommended them for running. Until now.
One of the best-known brands on the market, Vivobarefoot, recently launched the Primus Trail Flow, a vegan trail running shoe that's the brand's best effort to date to convince non-barefoot runners to join the clan.
On paper, the shoes are very similar to Vivo's other barefoot trail runners, the Primus Trail III, but don't let the looks deceive you. The Primus Trail Flow is a different beast altogether, thanks to its 3 mm puncture‑resistant sole, a 100% recycled mesh upper and minimalist rubber lugs.
It's also lighter than the Primus Trail III, my UK10 weighing a mere 242g. As expected from a Vivobarefoot shoe, you can practically roll the Primus Trail Flow into a ball, as there are no thick foam or rigid plates in the way.
As a result, you'll feel every lump and indentation on the ground, and get very little energy back from the sole. In fact, you won't get any, making you rely on your calf muscles to kick you forward. It can be quite taxing, especially for those who aren't used to walking barefoot.
From this perspective, the Primus Trail Flow isn't that much different from other barefoot shoes – why do I recommend it, then? The most important feature that elevates the shoes from other Vivobarefoot trail runners is the padding around the ankles.
It's still low profile, leaving ample space around the ankle bone to let you control every aspect of your stride. But instead of that super-minimalist padding most Vivo shoes use (see also my Vivobarefoot Pilgrim review), the Primus Trail Flow has a comparably supportive foam structure, which provides some support and reduces chafing in the rear.
The lug setup is also worth mentioning. The lugs are deep enough to bite into soft ground, but nimble enough to allow you to navigate harder surfaces. In my experience, they work well on most surfaces you might come across during trail running, whether it's a dirt path, low vegetation, or mud.
Speaking of mud, there are no gaiters on the Primus Trail Flow to keep moisture out of the shoes, but the recycled mesh upper helps evaporate it quickly. Plus, the material also supports air flow in the shoes, keeping your feet from swelling too much.
Even if it did swell, there is more than enough room in the shoes. Even though there is space in the shoes, the Primus Trail Flow doesn't feel baggy, only 'foot-shaped'.
Another small detail I appreciate is that the sole curves up in front of the big toe, providing some protection against the inevitable encounters with rocks, roots, and other debris on the ground.
Would I recommend the Primus Trail Flow to someone who's never tried barefoot shoes? Absolutely not. If you went from running, let's say, in On's Cloudsurfer Max to the Primus Trail Flow, it might destroy your legs.
No, seriously: you can genuinely get injured if you run the same way in the Vivos as you do in high-stack running shoes. There certainly is a transition period when you learn to walk again, placing more weight on the front of the foot, like a ballet dancer. Heel strikers need not apply.
I would recommend going for walks first on softer ground, building muscle memory until you can tackle hard ground like concrete. It helps if you often walk barefoot at home, as it can reduce transition time since your muscles are somewhat used to moving naturally.
I've been wearing barefoot shoes for walking and hiking on and off for at least 5-6 years, and even though it shouldn't take you this long to get used to them, I only now feel strong (and confident) enough to give barefoot running a go.
(As an anecdote, I saw a woman tackling the Loch Ness Marathon – which is a road running race – in barefoot shoes last year, and she may have all the respect I can give. I can't imagine what that distance would do to my legs and joints if I wore barefoot shoes.)
I used to not recommend barefoot shoes for running, but the Primus Trail Flow convinced me to change my mind. It's the full package, offering the right amount of support around the ankles and a solid grip underfoot in a lightweight package.
If you've ever considered trail running in barefoot shoes, the Primus Trail Flow is your best bet. The shoes are available now in men's and women's at Vivobarefoot UK, Vivobarefoot US and Vivobarefoot AU for a recommended retail price of £150/ $190/ AU$300.
