The psychological and physiological effects of physical activity and fitness in children with type 1 diabetes
Maintenance of blood glucose control and psychological well being are both important health outcomes for children with Type I diabetes. Diabetes management, the balance of insulin, diet and exercise, interacts with all aspects of these children's health, however, to date the effects of exercise in this interaction are poorly understood. This is particularly so with regard to the effects of exercise on psychological health. The aims of the present study were to investigate the effects of physical activity and fitness on the psychological and physiological health of children with Type I diabetes. The hypotheses were 1) that higher levels of physical activity and fitness would be positively associated with both greater psychological well-being and lower HbA1c, 2) that increasing physical activity would increase psychological health and lower HbA1c. Participants were aged 9-15 years, diabetes duration more than 2 years. There were 39 participants in phase one. Physiological data collected were physical activity, aerobic fitness, sum of skinfolds, BMI and HbAjc. Psychological questionnaires used were the physical self perception profile for children, the self efficacy for diabetes scale and the diabetes quality of life for youths questionnaire. Physical self esteem and quality of life were significantly associated with both greater fitness and higher physical activity. There were no significant associations between HbAjc and either fitness or physical activity. Phase two was a randomised controlled trial to evaluate a 12 week physical activity intervention. Thirty-nine children were recruited to this phase, 27 experimental and 12 control, of these 14 experimental and 7 control children completed the study. Data were collected as in phase one. When differences between the groups at time I were taken into account the only significant effect of the intervention was an increase in the BMI of the experimental group. There were increases in the hypothesised direction for aerobic fitness, perceived sports competence and perceived condition competence. Skinfold thickness and self efficacy for diabetes decreased significantly in both groups, strength competence increased significantly in both groups. There was no significant effect on HbA,,. Sample size was small and therefore the results must be treated cautiously due to the possibility of Type 2 error. iii It was concluded that both physical activity and fitness showed positive associations with psychological variables but that a physical activity intervention programme did not lead to significant increases in these variables. It is suggested that an intervention programme that incorporated physical activity and an educational or cognitive component would have a greater effect on the outcomes studied.