It shifts from normal speed → slow → fast again, creating impact and rhythm.
Action and sports ads cut to the music's beat. Change the speed in editing after generating (see speed ramp under editing techniques).
Public AI example available — Higgsfield contest 'Speed Ramp Video' (Nano Banana → Higgsfield video → After Effects ramp)
Speed ramp: a trail runner sprints at real-time speed across a forest path, slows to slow motion as she leaps over a stream, then snaps back to full speed, camera tracks alongside, 35mm lens, dappled sunlight, powerful rhythmic mood, 5-second shot.
speed ramp: real-time run, slows to slow motion at the jump, then snaps back to speed