How do I adjust the fore-aft position of my cross-country binding, and why would I?

On NIS or IFP plate systems, the binding can be slid forward or backward by releasing a locking mechanism (usually a lever or catch) and sliding the binding along the plate rails. Moving the binding forward shifts your weight forward, which can improve glide but may make kick wax less effective. Moving it backward improves kick but may reduce glide. Classic skiers often adjust position based on wax performance and snow conditions; skate skiers typically set it once and leave it. Flat-mount bindings cannot be adjusted without remounting.