Abstract: A bottle holding device for forming a refillable dumbbell in conjunction with a bottle of the type including a main body portion which is closed at a bottom thereof and which tapers at an upper portion thereof to a reduced diameter neck having a reclosable bottle opening, the bottle holding device including an upper bottle engaging section for engaging the tapered upper portion of the bottle, a lower bottle engaging section for engaging the bottom of the bottle, and an adjustable tensioning handle assembly for pulling the upper and lower bottle engaging sections toward each other with an adjustable force when the bottle holding device is assembled with the bottle, so as to tightly grip the bottle therebetween, and for enabling a person to grasp the tensioning handle assembly to perform dumbbell exercises, the tensioning handle assembly including a lower lateral extension which extends outwardly from the lower bottle engaging section, an upper lateral extension which extends outwardly from the upper bottle eng