I recently received a pair of Inov-8 Road-X Lite 155 running shoes. I was very excited. Forrest Gump excited. “The best gift anyone could ever get in the wide world. New Shoes!” And when you get a new pair of shoes, there’s only one thing to do! Get runnin’!!!
(before I get to my thoughts on the 155’s, here’s a page with all the technical info).
Some background – what I’m looking for in a shoe is something lightweight, with neutral support. Simpler is better – I don’t want a lot of rubber between my foot and the road, because I believe that the human foot is a far better shock absorber than anything a shoe company can manufacture. I want a shoe that has enough rubber to protect my feet from rocks/glass/etc.., but not so much rubber that it interferes with my foot’s ability to function naturally. Last year, I ran in the Puma Faas 250’s. They were good, but I knew there had to be something even better and lighter out there. I came across the Inov-8 Road X-Lite 155, and it looked like it met all of my requirements. Light? Is 5.5 oz light enough for you? Check. Thin sole? 6 mm. Check. Neutral support? Check. Minimal heel/forefoot differential? 3mm. Check. Just looking at it, I knew it had the potential to be a very fast shoe.
I took them out for a few sessions, and just as I suspected, they were exactly what I was looking for. The greatest compliment you can pay to a running shoe is that you forget that you’re even wearing shoes, and that’s how I felt in the 155’s. They’re fairly narrow, so they hugged my foot well (i.e. no slipping around, kind of like spandex around your feet). The thin sole and low heel allowed for very natural mid-foot striking, and I was able to just… run! The only thing I wasn’t used to was the style of the sole, which is essentially just a flat piece of rubber (i.e. no deep “waffle type” grid). I like this because it’s really annoying when rocks get stuck in typical “waffle” soles. The only downside of no “waffle” sole is that you feel every rock when you step on it. So I wouldn’t take these out on rocky trails. But, they’re specifically called the “Road X-Lite 155”, implying they’re intended for the roads, so… stay on roads, tracks, and and well-groomed trails!
The next question, of course, is, “who should be running in the Road X-Lite 155?” We all know that there’s not one shoe for everyone, so I’ll just say…. most people? I really mean that, but with a BIG qualifier. I recommend the 155 for athletes who have spent enough time developing foot strength to run in a thin, neutral shoe without injuring themselves. I developed plantar fasciitis in 2007, when running in thick, “stabilizer type” shoes. I got rid of the pain relatively quickly, but I also decided that I never wanted it again. So I made a commitment to strengthening my feet and running in less supportive shoes, and I haven’t had plantar fascia issues since. (and yes, I will be racing Iron-distance events in these shoes, they are more than enough to keep you good for 26.2 miles… it drives me crazy when people think they need a thick, bulky shoe for longer races)
I believe that almost everyone can develop the foot strength to run in a minimal shoe, it’s just a matter of time. Some runners have the ability to run in the 155 now, and some may require strengthening and a program of running in progressively less supportive shoes before being ready for something like the 155. But in the end, going through the process is worth it, because running in the 155 is a joy.
Doug MacLean, Pro Triathlete 
Great review, Doug. I agree completely with you that people who want to run in a minimalist shoe need to develop foot strength so as not to get injured. For the more casual runner who wants to run in a minimalist shoe, I think they need to SLOWLY work up the mileage. Even more experienced runners need to be careful. Too many of my running friends have gotten injured transitioning to minimalist shoes, especially the Vibram five fingers, because they did too much too fast! With the current trend towards minimalist shoes, I strongly believe runners need to be educated on being cautious when they transition from more padded shoes. It will help keep them healthy and injury-free!
Along those lines, they offer a range of shoes designed to gradually get people strong enough for minimal shoes: http://www.inov-8.com/New/UK/Transition-Journey.html?L=26 . I haven’t tried any of the more cushioned models, so I can’t really comment on them, but it seems like a good idea, eh?
I’m currently running in Asics Neo 33’s and am interested in this shoe as I prepare for long distance duathlons. How do I know if my feet are strong enough? I too have had plantar fasciitis followed by a series of stress fractures, and I am not interested in that again!
Good question… I think the best way to build foot strength is combining a few different approaches 1) walk around barefoot whenever you can 2) do one-legged calf raises a few times per week, and 3) do your running in progressively lighter and lighter neutral shoes. The Neo 33 have moderate padding, so maybe on your next pair, try something with a little bit less padding. Eventually after going through several pairs, you can work your way down to something with minimal cushioning. My basic approach was kind of like such… I had training shoes in 2009, and racing shoes in 2009. My racing shoes from 2009 became my training shoes for 2010, and then I got something even lighter for racing in 2010. Seemed like a good approach, and it’s worked so far.