ABSTRACT
Weight bearing physical activity has been advocated to be a major means of promoting the development and maintenance of bone mineral density[1]. The encouragement of activity which may optimise the development of a dense skeleton in the growing years may have future beneficial ramifications in the incidence of osteoporosis and cardiovascular health in adulthood. Adult research has identified relationships between adult bone mineral status and the incidence of bone fracture in the aging population [2]. It is argued that practices which can optimise bone density in the growing skeleton could possibly prevent the onset of osteoporosis. Physical inactivity in the form of immobilisation or injury has been shown to result in bone loss[3, 4]. This loss has been attributed to reduced mechanical loading[5]. The risk of osteoporotic fracture in women depends on bone mass attained in youth as well as the amount of bone loss which occurs in post menopausal years. Although genetic endowment determines an individual’s upper achievable peak bone mass[6] there is still much to be learnt about the impact of intervention strategies, in particular exercise in early life. There is a lack of knowledge concerning the laying down of bone mineral during the growing years[5]. Factors such as genetics, nutritional sufficiency, hormonal status, lifestyle factors (eg. smoking and alcohol), and mechanical loading through physical activity have been recognised as some of the potential determinants of bone mass development during childhood and adolescence. Recker[7] has proposed that not attaining sufficient bone mass during childhood and adolescence may be a contributing factor to bone fragility in the elderly. As a consequence, it is recommended that attaining optimal bone mass during youth may be a significant factor in the prevention of osteoporosis in later life. The purpose of this study was to examine the influence of extra weight-bearing physical activity on health related performance parameters and bone density of 9-11-year old girls.
