The status and level of health of an intensively growing adolescent and young man's body is a multifactorial process inextricably linked with the features of legally valid education and training systems officially adopted in each country of the world [1]. The research shows that "the human body is constantly affected by three streams of information, sensory, perceived by the senses through the first signaling system, verbal (oral and written words) through the second signaling system, and structural (components of food and inhaled air) entering the body through the gastrointestinal tract [2] ,[3]. His research shows that "mental factors are more important for adaptation and preservation of health than climatic factors." This is confirmed by modern scientific achievements in the field of age physiology, which note that the main point of preventing negative environmental influences on the growing body of both adolescents and youth is the accumulation of an accurate database on the distribution and identification of sources (factors) of their health disorders [4,5]. In connection with the above, it is of particular importance to determine the most scientifically significant integral morphofunctional parameters of growth and development in an intensively growing individual, which reflect the adaptive abilities of the individual and his adaptation to the conditions of a specific living environment [6,7]. The really significant indicators of the success of physiological adaptation to the processes of educational activity include the effectiveness of adaptation to the learning process in general education, professional and higher educational institutions; the success of both current and examination performance; stability in the learning process of the functional status of the student's body in the absence of sudden shifts in the manifestation of psycho-physiological functions; absence of pronounced signs of fatigue when performing educational activities [8,9]. Any stable adaptation of the body to the conditions of training and in the field of professional activity has its price, which can manifest itself in the direct deterioration of those functional systems that bear the greatest burden during the adaptation process [9]. This process is accompanied by a marked increase in functional disorders in a growing body, determining the growth rate of chronic forms of pathology among adolescents [10]. Educational and professional adaptation of a growing organism is one of the types of human physiological adaptation, which is an important area of scientific research. High information loads in modern secondary and higher schools cause emotional tension in students, the development of nonspecific stress reactions, and change the type of relationship between the body and the environment, disrupting the processes of adaptation and the process of its ontogenetic development [11].

The level of physiological adaptation was assessed among first-year female students from urban and rural areas, considering both physical development and the functional status of the cardiorespiratory system at rest and under physical activity during their learning process. Physical development was evaluated using somatometric measurements, including height, body weight, chest circumference, and chest excursions. The harmony and level of physical development were determined based on percentile methods. Physiometric assessments at relative rest included measurements of vital lung capacity (VC, L), respiratory volume (TV, mL), heart rate (HR, min⁻¹), and blood pressure (BP, mmHg) both systolic (SBP) and diastolic (DBP). External respiration parameters were measured using a dry spirometer to evaluate vital capacity (VC, L), tidal volume (TV, mL), and expiratory reserve volume (ERV, mL). Physical load was applied using the squat test according to the method of G.N. Apanasenko (2000), enabling evaluation of adaptation features under stress. Based on the collected data, integrative indices were calculated mathematically, including the body mass index (BMI, g/cm²), Erisman index, and vital index (VI, mL/kg), to provide a comprehensive assessment of physiological status.

Data were analyzed using SPSS version 26. Descriptive statistics, including mean ± standard deviation (SD), were calculated for all variables. Paired t-tests were used to compare pre- and post-load measurements within groups, while independent t-tests compared differences between urban and rural groups. A p-value less than 0.05 was considered statistically significant. Correlation analyses were performed to assess relationships between cardiorespiratory parameters and physical development indices.

The study protocol was reviewed and approved by the Institutional Ethics Committee of the Department of Biology, College of Education for Pure Science, Diyala University, Diyala, Iraq. Written informed consent was obtained from all participants or their legal guardians before enrollment. The study was conducted in accordance with the Declaration of Helsinki and local ethical guidelines to ensure participant confidentiality and safety.