title: Birth size, infant weight gain, and motor development influence adult physical performance.
abstract: OBJECTIVE
  Adult physical performance is recognized as a marker of both current physical capacity and future health. The aim of the study was to examine the independent influences of birth weight, infant weight gain, and infant motor development on a variety of adult physical performance outcomes, in terms of muscular strength, muscular endurance, and aerobic fitness.
  
  
  METHODS
  The study population consisted of 4304 individuals from the Northern Finland Birth Cohort 1966 (NFBC 1966) with anthropometry measured at birth and at 1 yr. Infant motor development at age 1 yr was assessed by parentally reported age at first walking supported and standing unaided. At follow-up, aged 31 yr, muscle strength was measured using a handgrip dynamometer, muscle endurance was measured using a timed trunk extension test, and aerobic fitness was estimated from heart rate immediately after a standardized step test.
  
  
  RESULTS
  Birth weight was positively associated with muscle strength and aerobic fitness at age 31 yr, and these associations were independent of adult body size (P < 0.001). Greater infant weight gain between 0 and 1 yr was associated with lower muscle endurance (P = 0.004) and poorer aerobic fitness (P = 0.002); these associations seemed to be mediated by adult body size. Independent of infant birth weight and adult body size (height and weight), earlier infant motor development was associated with greater adult muscle strength (P < or = 0.001), muscle endurance (P < 0.001), and aerobic fitness (P < 0.001).
  
  
  CONCLUSIONS
  Higher birth weight, lower infant weight gain, and earlier infant motor development independently predict higher levels of adult physical performance for muscle strength, muscle endurance, and aerobic fitness at age 31 yr.
authors.affiliation: MRC Epidemiology Unit, Institute of Metabolic Science, Cambridge, United Kingdom.
authors.forename: Charlotte L
authors.initials: CL
authors.lastname: Ridgway
authors.forename: Ken K
authors.initials: KK
authors.lastname: Ong
authors.forename: Tuija
authors.initials: T
authors.lastname: Tammelin
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Sharp
authors.forename: Ulf
authors.initials: U
authors.lastname: Ekelund
authors.forename: Marjo-Ritta
authors.initials: MR
authors.lastname: Jarvelin
mesh_terms: D000328:Adult; D000367:Age Factors; D001724:Birth Weight; D015444:Exercise; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009048:Motor Skills; D053580:Muscle Strength; D018482:Muscle, Skeletal; D010809:Physical Fitness; D011597:Psychomotor Performance; D012044:Regression Analysis; D013647:Task Performance and Analysis; D015430:Weight Gain