Changes

Ideally, the toe box of your shoes should be big enough that your toes can’t touch the sides or top of the shoe. If the toe box is slightly too small, it is easy to cut away the material to prevent contact. I generally leave a bridge of material from the very front of the shoe to near the laces to keep the sole from flopping around too much and just cut away the sides of the toe box.

[[File:Open Toe Box.jpg|frame|none|My Modified Nike Frees with the toe box opened out]]

====Shoe quality====

A bad seam or excess glue can cause a sharp edge that could tear up your skin. A shoe can fit correctly, but cause blisters due to manufacturing problems such as a bad seam. A shoe that bends in the wrong place can have a crease that causes a blister as well. Also, check that your insoles do not slip. Some double sided sticky tape between the shoe and the insole can prevent this.

* If the problem is occurring on hilly courses, make sure your downhill running form is right. Your foot should land and be in firm contact before your foot starts to act as a brake.

* Check your shoes are tied correctly and that on downhill sections any pressure on your feet to slide forward it taken by the area under the laces rather than allowing your feet to slide forward and cause the sides of the forefoot to rub.

* Watch where you’re placing your feet on trails. If you land with the edge of your foot on a rock, your foot can twist in your shoe, putting a huge shearing force on the skin at the sides of your feet.

* Consider modifying your shoes to cut open the area that rubs.