Shoe mileage

Add your pairs under Profile → Shoes and Runsei adds up the kilometres on each. Your default pair is stamped on a run when it arrives, and the post-run check-in asks Which shoes? when you want to say otherwise. A run only counts towards a pair when it carries that pair, so runs with no pair are counted separately and said so, never spread over your shoes.

The retirement distance is yours. 700 km is prefilled as a starting point and you can change it, because foam, weight and surface move it by hundreds of kilometres. Below 90% of your distance Runsei says nothing; from 90% it gives a heads-up; past it, it asks how the pair feels rather than telling you to replace it. Retiring a pair stops the nudge and keeps its kilometres.