Slipstream -- Kristin

slip·stream (slpstrm)

n.

1. The turbulent flow of air driven backward by the propeller or propellers of an aircraft. Also called race².

2. The area of reduced pressure or forward suction produced by and immediately behind a fast-moving object as it moves through air or water.

intr.v. slip·streamed, slip·stream·ing, slip·streams

To drive or cycle in the slipstream of a vehicle ahead.

Krsitin seems so strong that I would guess that other runners like to run in her slipstream so that their run isn't so hard.