The Effect of 16 Weeks of Regular Short Duration Physical Activity on Fitness Levels in Primary School Children
Hamlin, Mike, Ross, Jenny, Hong, Sang-Wan, Journal of Physical Education New Zealand
The aim of this study was to investigate the effect of a relatively short-duration, regular physical activity programme on selected health and fitness parameters in children. One hundred and forty eight children (aged 5-12 years) from a decile 10 rural Canterbury school were asked to complete a 16-week training programme consisting of 15 minutes of exercise, three days per week. Boys' height increased by 1.8 cm (95% confidence interval 1.0-2.7) and girls by 1.9cm (CI = 1.1-2.7) over the 16-week training period. Over the training period boys and girls increased in weight (0.9kg, CI = 0.5-1.4 and 1.1kg, CI = 0.6-1.5 respectively) but did not increase BMI or skinfold measurements. Boys and girls improved their broad jump (7.2cm, CI = 2.7-11.5 and 3.9cm, CI = -0.4-8.0 respectively) but boys decreased their sit and reach score (-1.4cm, CI = -0.3--2.4), while girls' sit and reach ability did not change significantly. Boys' and girls' absolute 550m run performance showed no significant change over the training period, however, when accounting for the change in body weight, girls significantly improved 550m performance by 6% (p = 0.006). A regular short-duration physical activity programme can maintain or improve aspects of children's health and fitness, which may improve further with an increase in duration or frequency of training.
New Zealand secular trend data suggests that for equivalent-aged children body weight increased by approximately 0.5 kg per year and aerobic fitness decreased (measured by a 550-m run) by about 3s per year over the last decade (Dawson, Hamlin, Ross, and Duffy, 2001). Similar trends in children's body weight and health-related fitness levels have been reported in Australia and children's age-related body weight continues to increase over time in countries such as England and Canada (Chinn and Rona, 2001; Dollman, Olds, Norton, and Stuart, 1999; Tremblay and Willms, 2000). These changes are of concern as evidence suggests poor fitness and obesity may increase the acute risk of cardiovascular disease and lead to further chronic health problems later in life (Twisk, Kemper, and van Mechelen, 2000). Inactive lifestyles in children result in low physical fitness levels (Pate, Dowda, and Ross, 1990), which are related to increased health problems such as low bone mineral density (Turner et al., 1992) and increased levels of obesity and Type I diabetes (Hypponen, Virtanen, Kenward, Knip, and Akerblom, 2000).
The genesis of these changes are likely to lie in the lifestyles of children; their levels of physical activity, and or what they eat (Dawson et al., 2001; Ross, 2000). The rectification therefore, is also likely to lie in enabling modifications to these lifestyles. The Physical Activity Taskforce Report (Physical Activity Taskforce, 1998) recommended a multisectorial approach to increasing the levels of physical activity in New Zealanders. More recently, the Ministerial Taskforce on Sport, Fitness and Leisure acknowledged the role of the educational institutions in the development of lifelong physical activity and even suggested lengthening the school day to incorporate additional physical activity for children (Ministerial Taskforce on Sport Fitness and Leisure, 2001). There is evidence, however, that the duration of physical activity required to improve health, while maintaining or improving academic performance, is such that lengthening the school day may be unnecessary (Dragicevick, Hill, Hopkins, and Walker, 1987; Lynch, 1981). These previously reported New Zealand school-based physical fitness intervention programmes have tended to target older intermediate school children (Dragicevick et al., 1987; Lynch, 1981) leaving the younger primary-- aged school children relatively unresearched. The purpose of this study was to investigate the health-related physical fitness changes in primary school children resulting from a 16-week, regular, relatively short-duration, physical activity programme undertaken during normal school hours. …