what is a training bra
A training bra (also trainer bra or bralette) is a lightweight brassiere designed for girls who have begun to develop breasts during puberty when the girl's breasts are not yet large enough to fit a standard-sized bra. Breast growth is usually defined by the Tanner scale. Girls who are developing breasts are at Tanner stage I and II. Training bras are usually a lightweight, unlined, pullover style bra and feature a soft, elastic bra band and soft bra cups.