On the lightweight chassis, you get a sturdy Cordura mesh upper with TPU reinforcements on the inside arch, outside pinky toe area, and heel. He’s tried and competed at the top end of the competition, on many courses, with a variety of shoes. Whilst he notes that shoes alone don't determine the result, they are incredibly important for many obstacles and also a competitors’ confidence while running the course. I noticed the power band that runs behind the heel, draws the heel forward, which may attribute to the slighter firmer fit. When the Vapor Glove 4 landed, we wanted to see how it would perform under pressure. And who better to put it to the test than Ninja Warrior veteran, Fred Dorrington.

On the roads, I suspect outsole durability may be the factor limiting the lifespan of these shoes, but the outsole will certainly outlast the midsole foam in an average running shoe. Gym workouts and easy treadmill miles are smooth. I feel in a short space of time, the 4's have become my go-to, with a number of welcome updates from the Vapor Glove 3. Will definitely be recommending them to my fellow Ninjas!

The ground feel is similar to the Vibram V-Alpha’s if you are looking for a closed toe shoe that keeps the excellent proprioception offered by this style of sole.

Merrell Vapor Glove 4 is a commendable minimalist, zero-drop trainer that exceeds at providing the right amount of protection and proprioception. Despite these concerns, I never really noticed a huge detrimental impact on my running and I even suspect the slight differences in design from other barefoot shoes helped strengthen the little bones and muscles in my feet even further. Lower marks for the initial hassles for an otherwise great fit. Gait Cycle PerformanceMerrell’s combination of Vibram soles with a Cordura mesh upper offers substantial protection while remaining featherlight and ultra-responsive. For the experienced barefoot runner (or those willing to take on the learning curve) this is an essential shoe. Here are his thoughts on the Vapor Glove 4 (as well as the Vapor Glove 3), compared to other shoes in this space: The heel area feels harder, and also a lot narrower, which provides a more rounded fit to the heel. After initial testing, they appear a little more sensitive, though possibly slightly less stable that the Vapor Glove 3. I do feel that the 4 is more robust than its predecessor.