I got a pair of highlanders last week, wore them around the house for a couple of days and went for a trot. Came back after 5 (flat) miles with a blister the size of our house on my achillies tendon from the heel cup.

I've left it a week, been out running twice in other shoes with no problems, have put the highlanders on again to mooch about in and the heel cup is already starting to rub a blister.

Any ideas about softening the heel cup / stopping blisters please?