For many years, global navigation satellite systems (GNSSs) have been used in professional navigation, land surveying and transport. The last decade has been a period of extending the area of their use to social applications, including those related to sports and recreation. Nowadays, both handheld recorders and mobile phones equipped with GNSS modules are widely used in fitness. Moreover, due to the popularisation of jogging, a mobile phone has become one of the essential navigational instruments which enables, inter alia , the determination of the distance covered by an amateur athlete, the duration of completing the route and the athlete’s speed. However, each of satellite-based solutions is characterised by a different positioning accuracy and positioning availability, which have a decisive influence on the reliability of the parameters being measured. The article proposes a new measure of positioning accuracy, the stadium cross track error (SXTE) with a confidence level of 95% and 68%, as a universal comparison criterion for satellite sport receivers. The application of the method is presented with the example of receivers used in nine Samsung Galaxy series mobile phones. The method uses an athletics stadium that meets the International Association of Athletics Federation’s standard for the running track length (400 m). The study demonstrated significant differences in positioning accuracies of particular GNSS receivers in Samsung Galaxy series mobile phones while allowing their accuracy to be unambiguously assessed.

Background: The human body is exposed to stressors on a daily basis. Short-term exposure to a particular stressor can cause the release of inflammatory markers – including c-reactive protein (CRP). EEG neurofeedback is a noninvasive form of therapy that aims to improve brain function. Neurofeedback is a type of feedback based on brain activity. Methods: The research process was performed by a group of 80 men who were divided into 2 research groups and 2 control groups. In the first research group and the first control group, the stressor of high temperature was applied, while in the second research group and the second control group, the stressor was physical exertion to refusal. Meanwhile, blood samples were taken to visualize inflammatory markers. These were taken before and after the stressor, as well as before and after the application of EEG neurofeedback. Results: In research group after EEG neurofeedback intervention, the level of CRP significantly dropped in the measurement after stressor implementation. Analysis of the SMK test revealed a significant influence of both factors (time F = 13.525, P = .035; state F = 10.658, P = .047) and their interaction (F = 16.709, P = .026). Same statically significant decrease was observed in the level of rect. abdom. EMG was after physical work after neurofeedback. In all tests, a decrease in the EMG amplitude of upper trap. was observed after physical work before neurofeedback with its further increase after neurofeedback. After neurofeedback training, the results of the 3 tested parameters of the sensorimotor coordination test performed after the second heat stressor improved statistically insignificantly compared to the values obtained before. Conclusion: This article shows the effect of EGG neurofeedback on reducing the negative effects of stress exposure in humans. The study showed that the level and a pattern of EEG neurofeedback influence and significance is different depending on the applied stressor. Furthermore, the level of EEG neurofeedback influence and significance in decreasing the stressor effect is different depending on the examined sphere.

The popularity of sports and recreational receivers of the global navigation satellite systems is steadily increasing and provides athletes, coaches, and scientists with a wealth of information on movement occurring both horizontally and vertically. Under mountainous conditions, considering the effort put in by the athlete as well as their safety, the elevation parameter appears to be particularly relevant. The aim of the study was to propose a methodology for assessing sports receivers in terms of their determination of the elevation component based on digital elevation models while paying attention to the appropriate measures for testing these devices. The methodology was applied for wrist-worn global navigation satellite systems’ receivers used by the participants of an uphill running event. In terms of elevation determination, the most accurate three receivers (same model) were those supported by the barometric altimeter, in which the Root Mean Square result obtained ranged from 3.6 to 4.1 m. The majority of receivers underestimated the total elevation gain, the mean value of which was −3.8%, which does not appear to be affected by the reception of two global navigation satellite systems or the use of a barometric altimeter. The error characteristics were common within the group of receivers of a particular manufacturer.

Global Navigation Satellite Systems (GNSSs) have revolutionised many areas of human life by providing location, navigation, tracking, mapping and timing capabilities. The use of this technology would not be possible without receivers designed for specific applications. One of these areas is sport. The article discusses the advancements made in wearable sport devices over the past two decades (2003–2023) and uses Garmin’s Forerunner receivers as an example. Nineteen of the most advanced models were analysed chronologically and reviewed in three sections: physical properties, internal and external sensors and other functional aspects. The lists are preceded by a description of the historical background of the technology, an explanation of the general principles of operation and the identification of ground-breaking mobile devices before the year 2003. The summary identifies the most likely changes that will affect the publicly available, wearable sports GNSS receivers in the near future.

Introduction: Sports Global Navigation Satellite Systems’ receivers have been providing athletes, coaches, and scientists with valuable information on movement for over two decades. As these receivers are specific measuring instruments, there is a need to determine their accuracy. This paper presents a relatively simple methodology for assessing sports receivers of this type regarding their elevation determination. Material and methods: The methodology was based on the Digital Terrain Model of Poland, a discrete representation of the topographic elevation of the land surface. Three wearable devices from different years of manufacture were selected for the preliminary study by calculating the Root Mean Square (RMS), mean elevation error, and Total Elevation Gain (TEG) measures. The testing was conducted on two sections of varying length and elevation differences. Results: During the first trial, an instrument from 2019 came closest to the actual elevation (RMS = 7.0 m; mean error = -6.5 m), while during the second trial, it was an instrument from 2014 (2.5, -1.6 m, respectively). All the receivers overestimated the TEG factor during both trials. Conclusions: The applied methodology allowed the receivers to be distinguished. Due to the preliminary, pilot nature of the study, it is subject to certain limitations and recommendations listed at the end of the article.

Nowadays, mobile applications are essential tools for everyday life, providing users with anytime, anywhere access to up-to-date information, communication, and entertainment. Needless to say, hardware limitations and the diverse needs of different user groups pose a number of design and development challenges. According to recent studies, usability is one of the most revealing among many others. However, few have made the direct effort to provide and discuss what countermeasures can be applied to avoid usability issues in mobile application development. Through a survey of 20 mobile software design and development practitioners, this study aims to fill this research gap. Given the qualitative nature of the data collected, and with the goal of capturing and preserving the intrinsic meanings embedded in the experts’ statements, we adopted in vivo coding. The analysis of the collected material enabled us to develop a novel framework consisting of ten guidelines and three activities with general applications. In addition, it can be noted that active collaboration with users in testing and collecting feedback was often emphasized at each stage of mobile application development. Future research should consider focused action research that evaluates the effectiveness of our recommendations and validates them across different stakeholder groups. In this regard, the development of automated tools to support early detection and mitigation of usability issues during mobile application development could also be considered.