This review builds on earlier reviews and considers the development of strength characteristics from childhood through adulthood. Since strength is associated with size and biological maturation, these associations are also discussed. Finally, genetic determinants of strength and tracking of strength components over time are also reviewed.
Gaston Beunen and Martine Thomis
Gaston Beunen, Martine Thomis, Maarten Peeters, Hermine H. Maes, Albrecht L. Claessens and Robert Vlietinck
The aim of this study is to quantify the genetic and environmental variation in isometric and explosive strength (power) in children and adolescents, using structural equation models. Arm pull (static strength) and vertical jump (explosive strength, power) were measured in 105 twin pairs from the Leuven Longitudinal Twin Study. Boys and girls were tested at annual intervals between 10 and 16 years and at 18 years. Path models were fitted to the observed strength characteristics and a gender heterogeneity analysis was performed at each age level. A model including additive genetic and specific environmental factors (AE-model) allowing for a difference in total phenotypic variance or in genetic/environmental variance components in boys and girls best explains both strength characteristics at most age levels. The additive genetic contribution for isometric strength varies between a2 = .44 and a2 = .83, and for explosive strength between a2 = .47 and a2 = .92, except at 16 years in males. In conclusion there is good evidence that during the growth period both static and explosive strength are under moderate to moderately strong genetic influence.
António Prista, Leonardo Nhantumbo, Silvio Saranga, Vítor Lopes, José Maia, André e Seabra, João Vinagre, Carole A. Conn and Gaston Beunen
Physical activity (PA) in children/adolescents of both genders from a rural community in Mozambique was estimated by accelerometry and by questionnaire and was compared with PA of Portuguese youth. Total PA, moderate (MPA), vigorous (VPA) and very vigorous (VVPA) were evaluated. Mozambican boys were more active than girls. Intensity of PA declined significantly with age. Survival activities, such as household tasks, were the predominant mode of PA. Compared with Portuguese children/adolescents, Mozambicans had significantly higher total PA; showed less decline of PA with age and engaged in fewer minutes at higher intensity PA. Environmental factors likely explain documented differences.
Élvio R. Gouveia, José A. Maia, Gaston P. Beunen, Cameron J. Blimkie, Ercília M. Fena and Duarte L. Freitas
The purposes of this study were to generate functional-fitness norms for Portuguese older adults, to determine age and sex differences, and to analyze the physical activity–associated variation in functional fitness. The sample was composed of 802 older adults, 401 men and 401 women, age 60–79 yr. Functional fitness was assessed using the Senior Fitness Test. Physical activity level was estimated via the Baecke questionnaire. The P50 values decreased from 60 to 64 to 75 to 79 yr of age. A significant main effect for age group was found in all functional-fitness tests. Men scored significantly better than women in the chair stand, 8-ft up-and-go, and 6-min walk. Women scored significantly better than men in chair sit-and-reach and back scratch. Active participants scored better in functional-fitness tests than their average and nonactive peers. This study showed a decline in functional fitness with age, better performance of men, and increased proficiency in active participants.