Pumping is the act of deliberately controlling pressure: heavy on backsides and light on frontsides. Put another way, pumping is getting heavy on surfaces that face where you want to go, and getting light on surfaces that face toward you.
When you pump a turn, you’re pumping and turning at the same time. This advanced skill increases traction, speed and safety. (Win, win, win!) And it gives you the energy — the Sine Wave of Love — to shred very technical trails.