Physical fitness and training in chronic childhood conditions

Abstract

Chapter 1 is a general introduction with background information about physical fitness and training in healthy children and children with a chronic condition. Chapter 2 describes a systematic review on the physical fitness in survivors of acute lymphoblastic leukaemia (ALL). The analysis showed that the physical fitness in childhood leukaemia tends to be reduced, which suggests the need for engagement in regular physical activities to increase their functional capacity. In Chapter 3 we evaluated the physical function and physical fitness in Dutch survivors of childhood leukaemia 5-6 years after cessation of chemotherapy. The evaluation showed that even after cessation of treatment, there were still clear late effects on motor performance and physical fitness. Chemotherapy-induced neuropathy and muscle atrophies are probably the prominent case for the reduced values. In Chapter 4, we described the efficacy of exercise therapy on functional ability, quality of life, and aerobic exercise capacity in children with JIA by means of a systematic review. The analysis indicated that, overall, there is some evidence that exercise therapy can improve functional ability, health-related quality of life, physical fitness, and pain. However, the effects are not statistical significant. All studies (both, included and excluded) demonstrate that exercise therapy does not show detrimental effects on the short term and does not exacerbate arthritis. The large heterogeneity in outcome measures, emphasise the need for a standardized assessment or a core set of functional and physical outcome measurements suited for health research to generate evidence about the possible effects of physical exercise for patients with JIA. We compared in Chapter 5 the aerobic and anaerobic exercise capacity of children with juvenile idiopathic arthritis (JIA) with healthy controls in a large cohort, to determine if there were differences based on disease onset type, and to examine the relationship between aerobic and anaerobic exercise capacity in children with JIA. This study demonstrated that both the aerobic and anaerobic exercise capacity in children with JIA are significant decreased. In Chapter 6, we conducted a similar study in adolescents with JIA. In this study we examined the aerobic and anaerobic exercise capacity in adolescents with JIA compared with healthy peers, and to assess associations between disease-related variables and aerobic and anaerobic exercise capacity. The results demonstrated that also the adolescents have an impaired aerobic and anaerobic exercise capacity compared to their healthy peers. The likely cause for this significant impairment is multifactorial and needs to be revealed to improve treatment strategies. The combined sample of 87 subjects with JIA is a lager cohort than in any previous single study of exercise capacity. To our knowledge, physical intervention studies have not been performed in children with Osteogenesis Imperfecta. Therefore, we describe the findings of a randomized controlled trial on the effects of a physical training program on exercise capacity, muscle force and subjective fatigue levels in 33 patients with mild to moderate forms of Osteogenesis Imperfecta (OI) in Chapter 7. The patients in this study were randomly assigned to either a 12-week graded exercise program or care as usual for 3 months. After the exercise program, peak oxygen uptake, relative VO2peak, maximal working capacity, and muscle force were significant improved compared to control values. These results show that a supervised training program can improve physical fitness and muscle force and reduces levels of subjective fatigue in a safe and effective manner.