International SportMed Journal - Volume 5, Issue 4, 2004
Volume 5, Issue 4, 2004
Author Walter R. FronteraSource: International SportMed Journal 5, pp 228 –229 (2004)More Less
Extracted from text ... Editorial: The mature athlete International SportMed Journal, Vol.5 No.4, 2004 http://www.ismj.com Official Journal of FIMS (International Federation of Sports Medicine) 228 ISMJ International SportMed Journal Editorial The aging of the population is a recent natural process that generated significant scientific interest in the 20th century. During the last decades of the 20th century, dramatic demographic changes in many countries around the world were consistently reported by the World Health Organization (WHO). For example, the percentage of persons older than 60 years on the planet increased from 6.9% in 1900 to 10% in 2000. In addition, the WHO has projected ..
Source: International SportMed Journal 5, pp 230 –245 (2004)More Less
<I>Objective:</I> The purpose of this review is to examine the social and contextual resources in the USA related to the initiation and maintenance of regular physical activity among older adults, as a basis for cardiovascular risk reduction, and to summarise directions for future research and intervention. <br><I>Data sources:</I> Using journal scans and computerised literature database searches, reviewed literature that incorporated perspectives central to understanding the multidimensionality of physical activity initiation and maintenance in older adults, specifically related to relevant social and contextual resources, were selectively reviewed. The reviewed literature was designed to highlight recent findings and provide recommendations for future research. Using journal scans and computerised literature database searches, studies that incorporated perspectives central to understanding the multidimensionality of physical activity initiation and maintenance in older adults, particularly related to relevant social and contextual resources, were identified. <br><I>Study selection and data extraction:</I> Studies that assessed physical activity behaviour(s) as an outcome variable, and focused on the behavioural context, social context, cultural factors, situational factors, physical environment, and organisational resources, were included. Specific variables within each study that provided an empirical and conceptual understanding of social and contextual resources related to physical activity initiation and maintenance among older adults were extracted for the purposes of this review. <br><I>Data synthesis:</I> Findings specific to social and contextual resources of physical activity among older adults were categorised by logical groupings of similar findings. Given the early stage of research attempting to integrate findings to provide a social contextual understanding of physical activity among older adults, this paper presents a descriptive review of the literature. <br><I>Conclusions:</I> Approaches to promoting physical activity among older adults must emphasise social and contextual resources, as well as cultural relevance, to promote physical activity. A multidimensional perspective to understanding physical activity among older adults represents a significant effort to link behavioural, social and biological sciences to generate new understandings and direct efforts in the prevention and management of cardiovascular disease.
Exercise and growth hormone in the aging individual, with special reference to the exercise-induced growth hormone response : review articleSource: International SportMed Journal 5, pp 246 –261 (2004)More Less
<I>Objective:</I> This review examines the mechanisms of growth hormone (GH) action, its effects on physical work capacity, and the effects of exercise training on the age-related decline in GH secretion. <br><I>Data sources:</I> Scientific research articles and literature reviews published in refereed journals prior to 01/04/2004 were scrutinised. Literature searches were conducted on electronic databases; articles not found in our search but cited by others were also obtained and textbooks published after 1985 were consulted. <br><I>Study section:</I> 443 sources citing GH research and related topics were consulted. 114 sources were considered to have information specifically relevant to the topic. <br><I>Data extraction:</I> By systematic collection of relevant information and by contrasting the results of research articles it was found that there is an age-related decrease in GH secretion that is not completely reversible with clinical or exercise interventions. This is associated with muscle atrophy, lower physical work capacity and increased adiposity in older individuals. Acute bouts of intense exercise result in significant increases in circulating GH in older individuals, and this release is greater in those who have prolonged training experience. Exogenous recombinant GH treatments are at best only equally effective, possibly because GH exerts greater influence when levels of other hormones, and their binding proteins, are optimised. <br><I>Conclusions:</I> High-intensity exercise largely offsets the age-related GH decrease by significantly elevating GH secretion. There is little evidence that exogenous GH treatment has a significant effect on physical work capacity. Hence appropriate exercise, including regular high intensity activity, could help minimise any age-associated decline.
The effects of creatine supplementation on muscle function and body composition in older men and women : review articleSource: International SportMed Journal 5, pp 262 –276 (2004)More Less
Aging results in decreased muscle mass (i.e. sarcopenia), decreased muscle strength, and decreased ability to perform daily tasks. Creatine supplementation has been shown to increase lean body mass and muscle strength, and reduce muscle fatigue in young individuals. The beneficial effects of creatine previously demonstrated in younger subjects would be substantial to elderly persons. <br><I>Objective:</I> This review examines the effects of creatine supplementation on muscle function and body composition in elderly individuals. <br><I>Data sources:</I> PubMed and SPORTDiscus databases were searched using the terms aging, creatine, creatine supplementation, creatine monohydrate, elderly and older adults, and phosphocreatine. Additionally, the references of papers identified through this search were examined for relevant studies. <br><I>Study selection:</I> Ten studies were identified that examined the effects of creatine supplementation in older adults (>50 years). <br><I>Data extraction:</I> Studies were critically evaluated and summarised in this narrative review, no meta-analytic procedures were performed. <br><I>Data synthesis:</I> Approximately half of the available studies demonstrate a beneficial effect of creatine on muscle function and body composition in older individuals, less than what has been reported in young subjects. <br><I>Conclusions:</I> Some, but not all studies of creatine supplementation in older individuals demonstrate a beneficial effect on muscle function and body composition. Future studies should better characterise the habitual physical activity of older research subjects, as this appears to be an important determinant of whether there will be an effect of the creatine supplement. Additionally, no studies have been conducted examining the effects of creatine supplementation on frail, institutionalized elderly subjects, a particularly vulnerable population for muscle dysfunction and sarcopenia.
The effects of squat training, using body weight, on the stiffness of tendon structures of the vastus lateralis muscle in middle-aged and older women : research articleSource: International SportMed Journal 5, pp 277 –297 (2004)More Less
<I>Purpose:</I> The effect of a 6-month squat training programme using body weight on the stiffness of tendon structures of the vastus lateralis muscle in middle-aged and elderly women (n=10, 48.3 <u>+</u> 10.8 yr) was investigated. <br><I>Methods:</I> The elongation of the tendon structures of the vastus lateralis muscle was measured using ultrasonography, while the subjects performed a ramp isometric knee extension up to the voluntary maximum (MVC). The relationship between the muscle force estimate and tendon elongation during the ascending phase was shown as a linear regression, the slope of which was defined as stiffness. The mechanical power during movement specific to maximal walking (WP) was determined using a non-motorised treadmill. <br><I>Results:</I> The squat exercise produced no significant changes in stiffness and WP. Among the subjects, however, there was a large inter-individual difference in the relative change of stiffness (i.e. -47.6 % to 124.3%). Regression analyses indicated that the subjects with a low initial level of stiffness and high body weight relative to MVC torque showed an increase in their stiffness values. Moreover, there was a significant correlation between the relative changes of stiffness and WP (r=0.846, p<0.05). <br><I>Conclusion:</I> For middle-aged and older women, (1) the effect of body weight resistance training on the stiffness of tendon structures of the vastus lateralis muscle partially depended on the initial level and the magnitude of body weight as a training stimulus, and (2) the training-induced change in stiffness influenced that in the mechanical power developed during maximal walking.