THE IMPACT OF SUMMER HOLIDAYS ON THE PHYSICAL DEVELOPMENT OF SCHOOL-AGE CHILDREN

The impact of summer holidays on the physical development of school-age children. Danylenko H.M., Cherniakova G.M., Merkulova T.V., Avdiievska O.H. The aim of the work was to investigate how gender, age and type of activity in summer affects the indicators of physical development (PD) of children. 1054 students (493 boys and 561 girls) aged 7-16 years took part in the study. The PD of children was studied by assessing somatometric and physiometric indicators. To assess the impact of the type of activity, a thematic questionnaire "Summer" was used. It was found that the gender and age of children had a significant effect on PD indicators in the summer. The most intense increase in body length occurred at the age of 7-12 years, body weight in 10-14-year-olds, and up to 16 years grouth of two parameters gradually slowed down. From the age of 10, children showed a positive increase in lung capacity (LC). In 15-year-old adolescents, a decrease in both indicators (ChC and LC) was found. It was found that 62% of children carried out educational activities in the summer, 24% of those were engaged in business activities, almost 40% of students were participants in hiking trips and 23% of children attended a children's health camp. The chosen type of activity in the summer influenced the indicators of the pupils' PD as follows: educational activities were accompanied by a decrease in body length and strength of the left arm, business activity, hiking trips and staying in a health camp were accompanied by an increased weight gain and an increase in LC. Реферат. Вплив літнього відпочинку на показники фізичного розвитку дітей шкільного віку. Даниленко Г.М., Чернякова Г.М., Меркулова Т.В., Авдієвська О.Г. Метою роботи було дослідити, як стать, вік та вид діяльності влітку впливають на показники фізичного розвитку дітей. Участь у дослідженні брали 1054 учні (493 хлопці та 561 дівчина) віком 7-16 років. Фізичний розвиток (ФР) дітей вивчався за оцінкою соматометричних та фізіометричних показників. Для оцінки впливу виду діяльності використовували тематичний опитувальник «Літо». Встановили, що стать та вік дітей мали достовірний вплив на показники ФР протягом літа. Найбільш інтенсивне збільшення довжини тіла відбувалося в дітей віком 7-12 років, маси тіла – у 10-14річних, і до 16 років приріст обох параметрів поступово сповільнювався. Починаючи з 10 років у дітей відмічався позитивний приріст життєвої ємності легень (ЖЄЛ). У 15-річних підлітків було встановлено зниження показників як окружність грудної клітини (ОГК), так і ЖЄЛ. Встановили, що 62% дітей протягом літа здійснювали навчальну діяльність, 24% опитаних працювали або займалися бізнес-активністю, майже 40% учнів були учасниками туристичних походів та 23% дітей відвідали дитячий оздоровчий табір. Обраний вид діяльності влітку впливав на показники ФР учнів таким чином: навчання сприяло меншому приросту довжини тіла та сили лівої руки, бізнесактивність, туристичні походи та перебування в оздоровчому таборі супроводжувалися підвищеним набором маси тіла та зростанням показників ЖЄЛ. ПРОФІЛАКТИЧНА МЕДИЦИНА 148 На умовах ліцензії CC BY 4.0 In recent years, there has been a trend towards deterioration in children's health. This is partly due to negative socio-economic, environmental and psycho-emotional factors. The influence of constant stress and overload at school disrupts the mechanism of self-regulation of physiological functions and leads to the development of chronic diseases in children [2, 3]. Appropriate use of free time in the summer can have a positive effect on children and help them cope with stress after the school year. Wellness and recreation during summer help to improve and strengthen the physical and psychological health of children and restore their vitality. In addition, the organized recreation of schoolchildren during the holidays creates conditions for development of their creative abilities and prevents child’s neglect. Uncontrolled time is often associated with an increased frequency of manifestations of risky behavior (smoking, alcoholism, drug addiction), an increase in body weight, a decrease in physical activity and sleep disturbance [12]. Formation of healthy lifestyle skills among young people should be the primary task. Such active forms of summer recreation and health improvement as school and suburban camps, summer language camps, hiking trips need to be developed. It is worth paying more attention to the forms and methods of organizing summer vacations for school-age children, to update their content, to improve the technologies of medical and psychological-pedagogical support. The aim of this work was to investigate how gender, age and type of summer activity (education, business activity, hiking and recreation in suburban camps) affect the indicators of physical development of school-age children. MATERIALS AND METHODS OF RESEARCH The data used in the study were collected from March to September 2019. The study involved 1054 students (493 boys and 561 girls) aged from 7 to 16 years old, studying in secondary schools in Kharkov. Physical development (PD) of children was studied by assessing somatometric (height, body weight, chest circumference) and physiometric (lung capacity, muscle strength of the hands) indicators using standard instruments [4, 5]. We used the questionnaire «Summer» to assess the impact of the type of activity. Statistical processing was carried out using IBM's SPSS 17.0 (license N d47646601451106a68cb) software for Windows7 and MS Office 2010 (MXMM-7JXX8-4XHCV-P6HVY-C38T2). We used Student's t-test and Mann-Whitney test. The critical level of significance of statistical hypotheses is

На умовах ліцензії CC BY 4.0 In recent years, there has been a trend towards deterioration in children's health. This is partly due to negative socio-economic, environmental and psycho-emotional factors. The influence of constant stress and overload at school disrupts the mechanism of self-regulation of physiological functions and leads to the development of chronic diseases in children [2,3].
Appropriate use of free time in the summer can have a positive effect on children and help them cope with stress after the school year. Wellness and recreation during summer help to improve and strengthen the physical and psychological health of children and restore their vitality. In addition, the organized recreation of schoolchildren during the holidays creates conditions for development of their creative abilities and prevents child's neglect. Uncontrolled time is often associated with an increased frequency of manifestations of risky behavior (smoking, alcoholism, drug addiction), an increase in body weight, a decrease in physical activity and sleep disturbance [12].
Formation of healthy lifestyle skills among young people should be the primary task. Such active forms of summer recreation and health improvement as school and suburban camps, summer language camps, hiking trips need to be developed. It is worth paying more attention to the forms and methods of organizing summer vacations for school-age children, to update their content, to improve the technologies of medical and psychological-pedagogical support.
The aim of this work was to investigate how gender, age and type of summer activity (education, business activity, hiking and recreation in suburban camps) affect the indicators of physical development of school-age children.

MATERIALS AND METHODS OF RESEARCH
The data used in the study were collected from March to September 2019. The study involved 1054 students (493 boys and 561 girls) aged from 7 to 16 years old, studying in secondary schools in Kharkov. Physical development (PD) of children was studied by assessing somatometric (height, body weight, chest circumference) and physiometric (lung capacity, muscle strength of the hands) indicators using standard instruments [4,5]. We used the questionnaire «Summer» to assess the impact of the type of activity.
Statistical processing was carried out using IBM's SPSS 17.0 (license N d47646601451106a68cb) software for Windows7 and MS Office 2010 (MXMM-7JXX8-4XHCV-P6HVY-C38T2). We used Student's t-test and Mann-Whitney test. The critical level of significance of statistical hypotheses is p<0.05 [1].
The study was conducted with the written consent of the parents. It adhered to the principles of the Helsinki Declaration of Human Rights and approved by the Bioethics and Deontology Committee of the SI "ICAHC NAMSU".

RESULTS AND DISCUSSION
The study found that body length of boys increased by 2.4% and of girls -by 1.9% (p<0.05) for the summer period. The increase in body weight was greater in girls (7.1%) than in boys (6.8%) (p<0.05). The chest circumference index (ChC) increased by 3.3% in boys and by 4.0% in girls (p<0.05), while the lung capacity index (LC) increased by 1.85% in boys and decreased by 1.2% in girls. The indices of the right hand strength (SRH) increased by 37.9% in boys and by 38.2% in girls (p<0.001) and left hand strength (SLH) increased by 31.8% and 38.5% respectively (p<0.001).
The influence of the age on the parameters of the PD was investigated. Groups that differed in increase in body length were identified using the Duncan test. Children 7-12 years old had the largest increase in height (from 2.8% to 3.8%), 13-14-yearold pupils had an average increase in height (1.8%-2.2%) and 15-16-year-old adolescents had the lowest rates of increase in height (0.5%-1.3%) (p<0.05).
Studying the ChC indicators we found that the greatest increase was observed in children of 11-12 years (5.5% and 6.6%, respectively) (p<0.05) and it was only 1.4% in 15-years old adolescents (p<0.05). LC indicators were negative in children of 7-9 years and 15-years-old adolescents. A gradual increase in LC indicators occured from the age of 10 and the maximum was observed in 14-years-old children (4.5%) (Fig. 2).
The next stage was to determine the influence of the type of summer activity on the PD indicators of schoolchildren. It was found that 62% of children carried out educational activities during the summer, 24% of respondents worked or were engaged in business activities, almost 40% of pupils were participants in hiking trips and 23% of children attended children's health camp (Fig. 3).

Fig. 1. Height and weight gains in school-age children, %
Investigating the influence of educational activity, significant differences were found in the indicators of height and SLH. Children who did not study during the summer grew by (3.9±0.1) cm, and their SLH indicator increased by (6.0±0.2) kg/s, while those who studied grew by (3.5±0.1) cm (F=10.0 p=0.002) and the DLR indicator increased by (5.1±0.2) kg/s (F=7.05 p=0.008). The influence of educational activity on other PD indicators of children was not significant.

Fig. 3. Proportion of school-age children with different types of activities during summer, %
Summer business-activity significantly influenced body weight and LC indicators. In particular, those who were engaged in business gained weight (3.6±0.2) kg (F=7.9 p=0.005) and increased LC by (124.6±23.1) ml (F=16.4 p<0.001) and in those who were not engaged in business, the weight gain was (3.1±0.1) kg, and the LC increased by (21.4±12.4) ml.
The next activity investigated was hiking. According to the survey, this type of activity has a significant impact on СhС and body weight. ChC measurements showed that in schoolchildren who did not participate in the hikes, the indicator increased by (2.5±0.1) cm and in those who visited hikes increased by (3.1±0.2) cm (F=7,4 p=0.007). The body weight of children who did not go on hikes increased by (3.0±0.1) kg, and in those who went on hikes increased by (3.6±0.2) kg (F=9.7 p=0.002).
We have analyzed the works of foreign authors on this topic. Hippel P.T. et al found that BMI grows and changes faster during the summer than during the school year [8]. In national representative survey of Australian children Olds T. et al. found that holidays were characterized by longer sleep duration and much more time spent watching TV, playing videogames, lower vigorous activity and lower total daily energy expenditure [11]. Watson et al. suggests that the summer holiday period is characterized by increased fatness and decreased fitness. It is possible that these patterns may be due to changes in diet and/or time use (e.g. children may be less active, eat more and have more screen time during the school holidays, compared with the in-school period) [9].
Various assumptions have been made to explain the increase in body weight gain in children and adolescents during the summer. These include decreased physical activity, increased sedentary time, deterioration in nutrition and lack of school lessons [13]. According to Avery A. et al. [6] during the school year, children and adolescents have a more structured, consistent and controlled day than during vacations. In the summer, they have more options as for diet, physical activity or inactivity, more time to use gadgets, children suffer from sleep disturbances. Mahoney J.L. shows that adolescents who regularly took part in organized activities were at lower risk of obesity than those who did not [10]. Zinkel S. R. et al. studied 162 teenagers to assess the potential impact of the season on overall energy expenditure. No difference was found in energy consumption during summer and during the school year. The authors suggested that the main factor of weight gain in the summer is the increased consumption of calories from food and beverages [7].