Secular trends in anthropometric characteristics, physical fitness, physical activity, and biological maturation in Flemish adolescents between 1969 and 2005. - Matton,L.; Duvigneaud,N.; Wijndaele,K.; Philippaerts,R.; Duquet,W.; Beunen,G.; Claessens,AL.; Thomis,M.; Lefevre,J. (Am J Hum Biol, 2007)