back and forth

moving from one place to another and back again; "he traveled back and forth between Los Angeles and New York"; "the treetops whipped to and fro in a frightening manner"; "the old man just sat on the porch and rocked back and forth all day"

आयु बढ़ने के साथ हृदय की क्षमता में भी धीरे-धीरे कमी आती जाती है.

I started doing back and forth again and again.