Bone Accrual in Children and Adolescent Nonelite Swimmers: A 2-Year Longitudinal Study.

Objective: To examine differences in bone mass between children and adolescents swimming competitively at nonelite levels (locally and regionally) and nonathletes and to assess changes in bone mass in these 2 groups over 24 months after taking into consideration several known confounders of bone mass.

Design: Observational prospective study.

Participants: White nonelite swimmers (n = 128) and nonathletes (n = 106) 8 to 18 years of age from Memphis, Tennessee, USA.