Choosing different gear for different activities (e.g., Run vs Trail Run vs Treadmill)

With gear (i.e. shows), you can automatically attach a piece of gear to different activities: Running, Cycling, Hiking, Swimming, Walking, Other.

That's nice, but what I want to do is use different gear based on wheather I choose a Run or Trail Run. I use different shoes for these different activities.

Does anyone know if this is possible? I can't find a way to do it.