Short-term improvements in body composition, fitness levels, well-being, sleep habits and health knowledge for children and adolescents after a ten-week residential stay in the Danish Christmas Seal Homes – effects of adding a team-based health education and physical activity programme 

Background
Childhood overweight and obesity are global challenges affecting children and adolescents worldwide. The prevalence has increased considerably in the past decades; childhood obesity is considered one of the most severe public health challenges for the 21st century. Physical inactivity and childhood obesity are risk factors for cardiovascular disease later in life. Hence, action needs to be taken during childhood and adolescence. Single-component interventions focusing either on diet, physical activity (PA), well-being or screen time have been shown to have little or no effect. It would be interesting to study a multidisciplinary intervention such as a residential stay focusing on health knowledge, well-being, diet and PA. That can be done in Denmark at the Christmas Seal Homes (DCSH). The DCSH offer a ten-week residential stay for socially vulnerable children and adolescents aged 7-14 years, with DCSH staff-initiated activities that enhance the positive development of social interrelations, health awareness and education, well-being and daily physical activity. During the regular school year, the children attend daily sessions in smaller groups according to age. Children and adolescents at the DCSH face higher rates of low socioeconomic status and significant physical and psychosocial challenges compared to their peers. A high fraction of the children live with overweight or severe overweight, and many struggle with low self-esteem, bullying, poor self-reported life satisfaction and low quality of life. Additionally, common psychiatric diagnoses in this group include Attention Deficit Hyperactivity Disorder (ADHD), autism, and stress-related behavioural issues.

The combined PA and health education programme 11 for Health (11fH) encompasses recreational football drills and small-sided games and can be characterised as a team-based programme. Programmes like the 11fH, with frequent intense training sessions, can positively affect musculoskeletal, cardiovascular and metabolic fitness capacities through a combination of endurance training, vigorous intensity interval training (HIIT) and strength training. Furthermore, recreational football can stimulate intrinsic motivation for participation in PA. By focusing on social relations in exercises with pairs- and teamwork, recreational soccer has positively affected social and mental well-being with high enjoyment ratings and moderate ratings of perceived exertion. The social interactions in 11fH may stimulate motivation through a sense of belongingness, and team sports are proposed to ensure a higher degree of consistent participation and continuity of exercise compared to individual sports. For the socially vulnerable children and adolescents at the DCSHs, the 11fH programme could serve as an effective tool for positively affecting physical and psychosocial health.

Aims
The present thesis examines the impact of the standard (SG) residential stay at the DCSHs on physiological and psychosocial health variables. It evaluates the popularity of the 11fH programme at the DCSH (SG+) and whether its content would result in additional physiological and psychosocial health improvements than the standard programme.

Methods
614 children participated in the study, of whom 309 participated in SG (12.4±1.6 years) and 305 in SG+ (12.4±1.4 years). A crossover design was used over two years. A ten-week residential stay at the DCSH promotes a structured and predictable daily routine among children and adolescents with healthy food habits, daily PA and social engagement, using a multidisciplinary intervention based on a broad health definition that incorporates physical, social, and mental well-being. The standard programme for the SG group is based on diet and exercise policies recommended by the Danish authorities. In SG+, two weekly PA sessions from SG were replaced with 11fH sessions. The PA and health education programme 11fH comprised exercises designed to be captivating and socially inclusive, with integrated, evidence-based principles of small-sided football exercises. The 20 sessions consisted of activities with vigorous intensity, engaging and inclusive drills and exercises.

In this thesis, the primary outcome was the change in body fat percentage (BF%), and secondary outcomes were additional effects on body composition, fitness and exercise performance (measured by running, postural balance and standing long jump tests), blood pressure (BP) and resting heart rate (RHR), and PA and sleep patterns (measured with accelerometers). Furthermore, alterations in health knowledge, well-being, emotional and behavioural difficulties and sleep quality were assessed through questionnaires.

Results
As the primary outcome, BF% was lowered by seven percentage points during the ten-week residential stay (from 36% to 29% in SG+ and from 37% to 30% in SG), with no differences between groups. The drop in BF% was six percentage points for females (from 37% to 31%) and eight percentage points for males (from 36% to 28%) (Paper I). Furthermore, we observed increased intermittent exercise performance, fitness level, standing long jump performance, relative muscle mass, reduced systolic and diastolic BP, RHR and fasting saliva insulin, with no between-group differences (Paper I). The participants rated the 11fH programme as popular, with similar popularity scores (mean±standard deviations (SD)) of 3.5±1.0 and 3.6±0.9 (on a 1–5 scale) among female and male participants, respectively. Overall health knowledge increased significantly more in SG+ than SG over ten weeks (6.6% and 3.4%, respectively). In particular, health knowledge related to PA was increased by 7.2±20.5% and 4.7±21.7% in SG+ and SG, respectively, with a between-group difference in favour of SG+ by 3.4% (95% CI:0.6;6.2). Both groups increased their overall well-being scores by 4.54±7.17 arbitrary units (AU) in SG+ and 4.51±7.16 AU in SG, with no between-group differences (Paper II). Increased values were seen in all well-being subcategories, raising the well-being scores to national average levels at follow-up. In the strengths and difficulty questionnaire (SDQ), the total difficulty score of the participants indicated an elevated level of overall distress and impairment at baseline (>95th percentile); both groups had a reduced total difficulty score after ten weeks (no between-group differences).  

The results showed an alteration in the participants’ sleep patterns, as measured by accelerometers. They increased their time in bed, overall sleep duration and regularity index. They also reduced their sleep difficulty score, measured by questionnaires (no between-group differences).

The cortisol levels were lowered (non-significant) by 0.6±5.5 nmol/l and 0.5±4.7 nmol/l for SG and SG+, respectively (Paper III).

Conclusion
The three manuscripts in this thesis showed that a ten-week residential stay at the DCSH is an effective multidisciplinary intervention that resulted in essential and clinically relevant within-group improvements in BF%, fitness level and cardiometabolic health variables in socially vulnerable children and adolescents. Furthermore, the residential stay resulted in a marked within-group improvement in well-being and positive effects on emotional and behavioural difficulties and sleep quality. Moreover, there was an additional positive effect on health knowledge when substituting PA sessions in SG with a combined recreational football and health education programme, especially related to health knowledge of PA and the importance of vigorous intensity. However, no additional effects of the 11fH programme were observed regarding physiological health profile, fitness level, well-being, and sleep, which can probably be attributed to the fact that broad-spectrum and intense PA were already included in the standard programme. Future studies will examine the long-term impact of the ten-week residential stay and investigate whether participation in a motivating team sports programme and elevated health knowledge related to PA will impact health literacy and long-term adherence to PA and a healthy lifestyle.