- crisp
- smoothing
- tread gone
- worn through
Right shoe, sole up, toe at the top
Outer heel wear
The most common pattern on earth, and usually nothing to fix.
What it means
Rubber going from the back outer corner of the heel is the signature of a heel striker, which is roughly three out of four road runners. The foot lands slightly rolled outward, touches down on the outer heel, then rolls inward and forward to push off near the big toe. That short arc is normal pronation doing its job.
Because the heel takes the first hit on every stride, it wears first. Manufacturers know this and put the hardest carbon rubber back there. When you can see grey foam through the rubber at that corner, the shoe is close to done even if the rest of the tread looks fine.
On its own, outer heel wear is not a sign of overpronation or supination. It only starts to say something when the wear keeps going down the whole outer edge (see outer edge wear) or jumps to the inner heel and inner forefoot (see inner edge wear).
What to do about it
- Shop by heel rubber. Look for a full rubber crash pad under the heel rather than exposed foam pods, and you will get 100 more miles from the next pair.
- If you are curious about landing further forward, shorten your stride slightly and lift cadence by 5 percent rather than forcing a forefoot landing. Forced changes cause more injuries than they fix.
- Retire the pair when the foam shows through the heel or the cushioning feels flat, whichever comes first.
High-durability daily trainer
Full rubber coverage where you land. The pair to buy if you keep wearing through the heel.
Read my own shoesQuestions
Is heel striking bad?
No. Most elite marathoners heel strike at easy paces. Injury risk tracks total load and sudden changes in training far more than where the foot lands.
Why does only one shoe wear at the heel?
Small leg-length differences, a dominant leg, and cambered roads all load one side more. A big difference between shoes is worth a look from a physio; a small one is universal.