title: Advanced pubertal status at age 11 and lower physical activity in adolescent girls.
abstract: OBJECTIVE
  To examine the relationship between pubertal timing and physical activity.
  
  
  METHODS
  A longitudinal sample of 143 adolescent girls was assessed at ages 11 and 13 years. Girls' pubertal development was assessed at age 11 with blood estradiol levels, Tanner breast staging criteria, and parental report of pubertal development. Girls were classified as early maturers (n = 41) or later maturers (n = 102) on the basis of their scores on the 3 pubertal development measures. Dependent variables measured at age 13 were average minutes/day of moderate to vigorous and vigorous physical activity as measured by the ActiGraph accelerometer.
  
  
  RESULTS
  Early-maturing girls had significantly lower self-reported physical activity and accumulated fewer minutes of moderate to vigorous and vigorous physical activity and accelerometer counts per day at age 13 than later maturing girls. These effects were independent of differences in percentage body fat and self-reported physical activity at age 11.
  
  
  CONCLUSIONS
  Girls experiencing early pubertal maturation at age 11 reported lower subsequent physical activity at age 13 than their later maturing peers. Pubertal maturation, in particular early maturation relative to peers, may lead to declines in physical activity among adolescent girls.
authors.affiliation: Department of Recreation, Park, and Tourism Management, Pennsylvania State University, University Park, PA, USA. blb257@psu.edu
authors.forename: Birgitta L
authors.initials: BL
authors.lastname: Baker
authors.forename: Leann L
authors.initials: LL
authors.lastname: Birch
authors.forename: Stewart G
authors.initials: SG
authors.lastname: Trost
authors.forename: Kirsten Krahnstoever
authors.initials: KK
authors.lastname: Davison
mesh_terms: D000293:Adolescent; D050218:Body Fat Distribution; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D004958:Estradiol / Q000097:blood; D005260:Female; D015438:Health Behavior; D006801:Humans; D008137:Longitudinal Studies; D018670:Monitoring, Ambulatory / Q000295:instrumentation; D009043:Motor Activity; D050177:Overweight; D011627:Puberty
chemical_list: D004958:Estradiol