I highly recommend Grip Studs for running in winter conditions. They provide traction on ice and packed snow second only to full mountaineering crampons - which are of course not suited for running. The fact that they are carbide means that they last longer than regular or stainless steel. This is especially important in the mountains where one slope may be covered in ice and snow, and another exposed rocks which tend to quickly wear other spikes. The large auger-like threads on the Grip Studs help secure them to the soles of the shoes meaning that far fewer pull out than other brands. It is helpful to pick a suitable shoe model in which to install the Grip Studs. You want one that has large, deep, widely spaced lugs made of rubber that is not too soft. The large lugs provide a suitable surface into which to install the Grip Studs. The fact that the lugs are deep not only provides depth to screw the grip studs into but also provides traction on loose snow beyond what Grip Studs themselves can provide. Grip Studs real forte is hard-packed snow, but of course, running conditions will vary. The large spacing helps prevent the lugs from getting clogged with snow and ice. A sole made of firmer material allows the Grip Studs to be screwed into it, as opposed to just flexing under the twisting motion. I have had excellent results with installing Grip Studs on the La Sportiva Mutant. I recommend that the longest Grip Studs model be selected consistent with the thickness of the shoe’s sole, but taking into account that during use the sole will be compressed. You can even use different sizes of Grip Studs on different parts of the shoe’s sole.