Abstract: Mattresses and chaise longue cushions made of a core made of flexible polyurethane foam having two groups of rows perpendicular to the longitudinal axis of the core of continuous cavities each having an elongated cross section. Each of the elongated cross sections from about the center of the longitudinal axis of the core towards the end thereof is arranged in an oblique orientation relative to the mattress height. Between the two groups of rows of continuous cavities there is present one continuous cavity in a symmetric non-oblique orientation. This arrangement causes the vertebral column to be stretched and, hence, due to movements on the mattress or chaise lounge cushion, results in kind of vertebral column physical exercises producing some stretching effect.