This is likely a stupid question but here it does.
My son started running as a freshman in xc and is apparently pretty decent. He used to play soccer but he ran xc this fall and placed in the top 100 in the state of all levels of schools. He pushed a bit too hard and got hurt during footlocker. We don't have winder track where we're at but his coach is telling him he may be top 2 on the team in the mile and 2 mile. We got him spikes, but what length spike inserts she he run in; 1/4", 3/16" or 3/8" or something else? Is there any benefit to running in something longer or do you really want to go as short as you can?