Physical inactivity is the fourth largest behavioral factor contributing to bad health and mortality. Number of adults who are physically inactive is increasing in many countries, affecting prevalence of non-communicable diseases and general health of global population. Participation in regular physical activity reduces the risk of non-communicable diseases by improving muscular and cardiorespiratory fitness. However, currently 25% of adults in the world do not meet recommendations for physical activity. Physical activity is essential for healthy aging. The advantage of digital exercise apps over traditional approaches, especially among a younger, technologically advanced population, is that they provide an interactive, social, and personalized platform that helps users modify their own activity with minimal professional contact. Because mobile devices track users at almost all hours of the day, adolescents can seamlessly integrate health monitoring into their daily schedule. Therefore, a teenager can find a digital application for physical exercise that stimulates his kinesiological activity and thus has a positive effect on health. Mobile health apps are very popular today and provide new opportunities for changing healthrelated behaviors and managing chronic conditions. Typical fitness apps provide immediate access to health information, reminders, or help track progress in an exercise regimen. Health and fitness apps have gained popularity in interventions to improve nutrition (physical activity, and reduce sedentary behavior. It is necessary to state that there are not many papers that dealt with this area, which on the one hand was a difficulty in collecting sources, while on the other hand it was a challenge regarding scientific contribution. Smartphone applications are recognized as a potential and promising approach to increase adherence to physical activity guidelines. Educational system of schools, but also students and teachers, by using modern technology, get faster and more motivated access to scientific and professional data needed for teaching and learning, and achieve the set learning outcomes faster and better. In the beginning of 2020, the world was affected by coronavirus pandemic, and many countries around the world, including the Republic of Croatia, had to come up with various strategies to prevent the spread of the virus. Due to outbreak of this virus, many countries had to impose various rules and regulations to limit social life and education in order to reduce the spread of the virus. This referred to various types of isolation, ban on traveling and meeting in public places, sports activities, ban on holding concerts, and even going to work and school. This pandemic has had a very negative impact on people's lives as it has stopped life as it was known. Education was also stopped during the pandemic and schools were closed in almost 200 countries of the world, including the Republic of Croatia. It was during this period that distance learning began using modern technology. Information and communication technology is a generic term, defined as a diverse set of technological tools and resources used to communicate, create, disseminate and manage information. In Physical and Health Culture classes, this means all communication devices or applications, including heart rate monitors, speedometers, cameras, radio, television, smartphones, computers and network hardware and software, satellite systems and the like, as well as various services and applications related to them. More frequent use of information and communication technology in teaching Physical and Health Culture could contribute to an increase in quality of teaching Physical and Health Culture by using its many advantages, such as easy access to images, videos and other resources, the ability to easily explain complex information and motor skills, holding more interactive classes and expanding communication between students even after Physical and Health Culture classes. It is becoming increasingly difficult to protect children from exposure to technology and its negative impact on children's development, rest, physical activity and mental health. On the other hand, mobile devices are also recognized as a potentially useful tool in monitoring health and promoting aactive lifestyle and can potentially be used for diagnostic purposes in detection of acute coronary syndrome, arrhythmias or blood pressure and can help patients to reach their health and physical goals more easily. Today, there are numerous mobile applications created for sports activities such as running, cycling, sports training, then for healthy nutrition and water intake, body weight control and promotion of a healthy lifestyle. It is important to emphasize that mobile applications intended for physical exercise and sports training should also in other areas be implemented under the supervision of trained experts. They are equipped with advanced technological features, most notably Internet connectivity, global positioning system and built-in accelerometers, and offer the ability to create individualized and interactive applications for real-time data collection. These features, as well as widespread use and convenience of smartphones, make them an attractive tool for researchers in providing physical activity interventions. A part of information and communication technology are also modern digital watches that have appeared on a larger scale in the last five years, which are connected to smartphones and contain very serious applications that can not only monitor numerous student activities, but also directly provide them with important information, such as amount of calories burned, time spent standing and exercising, heart rate, types of activities they engaged in during the day, to warn them if they did not sleep enough considering their age, but also to warn them about nutritional activities that should be performed during the day, including the need to occasionally stop activities and briefly concentrate and relax, breathing calmly. The good thing about such classes is that a student can either determine the amount of daily movement himself or accept one of the proposed programs with regard to age, height and body weight. Such programs encourage many people to be physically active because it is in human nature to reach what they have chosen or set themselves as a goal. Through a smart watch connected to a smartphone, students can also receive messages from teachers about the need to perform various physical activities, which was very useful during online classes. Information and communication technology (ICT) is becoming an increasingly important part of teaching and kinesiology activities. Adolescents are responsible for starting to learn how to take care of themselves, and digital applications for physical exercise provide them with an opportunity to put their health in their own. The main goal of this doctoral dissertation is to determine to what extent is kinesiology activity of adolescents related to use of digital applications for physical exercise, and to knowledge of the possibility of using applications for physical exercise. Additionally, we wanted to determine whether kinesiology activity is conditioned by a positive attitude towards use of digital applications for physical exercise and whether kinesiology activity of adolescents is related to regional affiliation. Ultimately, the intention is to determine whether the social status of the family conditions better material support for the use of digital technology and whether it causes greater kinesiological activity in adolescents. Below are the research hypotheses: 1. There is a statistically significant positive correlation between kinesiology activity of adolescents and the level of use of digital applications for physical exercise. 2. There is a statistically significant positive correlation between kinesiology activity of adolescents and the possibility of using digital applications for physical exercise. 3. There is a statistically significant positive correlation between kinesiology activity of adolescents and their attitude towards the use of digital applications for physical exercise. 4. There is a statistically significant positive correlation between social status of the family and the use of digital technologies for physical exercise and kinesiology activity of adolescents. 5. Kinesiological activity of adolescents differs statistically significantly depending on the regional affiliation of students. Two questionnaires were used to collect data: the Croatian version of the Questionnaire (Vidaković-Samaržija and Mišigoj-Duraković, 2013) for assessing overall level of physical activity of younger school-aged children (PAQ-C) (Kowalski, Crocker and Donen, 2004), as well as Questionnaire for assessing students' attitudes in relation to the use of mobile applications intended for physical exercise with a total of 12 variables (Dubovečak, 2021). The research covered two regions in the Republic of Croatia: the coastal region with islands (the island of Krk) and the continental region (the towns of Petrinja and Velika Gorica). We wanted to see if there is a difference in the use of digital applications for physical exercise depending on the region and how much their use affects and if it affects kinesiological activity of adolescents. The cluster sample consisted of 8th grade elementary school students. Total sample was 349 students, with average age of 14 years with an equal gender ratio and is presented in detail in the research results chapter. Data were analyzed with descriptive statistics (mean values, dispersions, curve and flatness of the distribution) and normality of distributions (Kolmogorov Smirnov test) and hypotheses were tested with inferential statistics. In the area of correlation plot, bivariate correlations (zero order) were tested with the Pearson correlation coefficient. One-way ANOVA was used in the area of differential design for the fifth hypothesis. In case of inability to use ANOVA, the robust Welch test was used. The tests used were tested at the level of statistical significance p<0.05. In conclusion, it was established that kinesiology activity of adolescents is significantly and positively connected to use of digital applications for physical exercise, with knowledge of the possibility of using applications for physical exercise, as well as with positive attitude towards use of digital applications for physical exercise. The relationship is small, but statistically significant. Also, it was shown that there is a statistically significant difference in kinesiology activity depending on regional affiliation, and that it is statistically significantly lower in Velika Gorica compared to Petrinja and coastal Croatia with islands. And finally, the assumption that social status of the family is related to kinesiology activity of the students was not confirmed. The original scientific contribution is reflected in the creation of a new conceptual methodological framework for measuring the use of digital applications for physical exercise and the connection with the kinesiology activity of adolescents, which can be used in the long term and contribute to research on the same population and in other countries that have similar socio-demographic characteristics of adolescents as in Croatia. The obtained data are significant in theoretical space, which, considering relatively less research of modern digital applications, is expected by a more modern paradigmatic framework.