Drop is the single most misread number on a spec sheet. It doesn’t tell you how soft a shoe is, how fast it is, or how good it is. It tells you how much higher your heel sits than your forefoot — and therefore which part of your leg does more of the work.
What the number measures
Take the stack height under the heel, subtract the stack height under the forefoot, and that difference is the drop. A shoe with 36mm at the heel and 30mm at the forefoot has a 6mm drop.
Note what that means: two shoes can have identical drop and feel completely different, because one might be a low, firm racer and the other a tall, soft cruiser. Drop is a relationship between two numbers, not a quantity of shoe.
Low drop vs high drop
Lower drop puts more demand on the calf, Achilles and foot. It encourages a flatter landing and a slightly shorter stride.
Higher drop shifts load up the chain onto the knee and quad, and takes some strain off the Achilles. It suits runners who land heel-first, which is most people, most of the time.
Neither is correct. It’s a preference and a history question: a runner managing a grumpy Achilles usually gets on better with more drop, and a runner with knee niggles sometimes gets on better with less.
Changing drop without picking up an injury
Drop changes are load changes, and tissue adapts slower than enthusiasm. Dropping several millimetres overnight is one of the most reliable ways to strain a calf.
Introduce a new drop gradually — short easy runs first, keep your old shoes in the rotation, and give it a few weeks before it becomes your long-run shoe. Slight, temporary calf tightness is normal. Sharp or persistent pain is not.
How to use it when shopping
Find the drop of the shoe you currently run happily in. Use that as your anchor and stay near it unless you have a specific reason to move. It’s a far more useful filter than anything else on the label.
Drop tells you where the load goes — not how much shoe you’re getting.
Got a question this didn’t answer? Email info@pureendurance.co.za.