When buying road shoes, you need ones that are specific to your gait, but this isn’t the case with trail running shoes. The overall fit, comfort and suitability for the terrain are the most important things to consider. The trail shoe market has been heading down the minimalist route recently, so many shoes are neutral or lacking in any support at all. A lack of support does help to reduce weight, but you’ll need to have sufficient foot and ankle strength to wear those shoes.
Choose a shoe that’s suitable for the terrain you’ll be running on. A stiff sole will provide better protection against rocks and uneven ground than a cushioned one will. Cushioned shoes are better suited to a mixture of road and trail and longer-distance runs. Front-of-shoe toe protection, bump strips and thicker material will help to protect the foot, but they also add weight.
Probably the biggest difference between road and trail shoes is improved grip. Deep-lugged shoes will give you the best grip on the fells or muddy trails, although this usually means sacrificing comfort. Many trail shoes have ismilar treads to road shoes but stiffer, with slightly deeper lugs, and made from a stickier rubber for better grip. Occasional trail runners will find this type of shoe less severe and better for all-round use.
Trail shoe uppers vary greatly, so what you buy depends on where you’ll be running. I find waterproof uppers a waste of time because if you’re running through streams and deep puddles, the water will always get into the shoes -but for all-round use, including hiking, they’re a solid option. Most manufacturers use mesh material of differing stiffness and gauge, and some offer layers of cushioning. Lightweight shoes will have minimalist uppers which are great for racing but may bot be as durable or provide the comfort required for longer training runs.