Latvian Academy of Sport Education

This study presents a comprehensive review of current technologies used to reduce exhaust gas emissions from ship propulsion systems in maritime transport. It compares the operational principles, environmental impacts, and economic feasibility of each method. The analysis highlights the advantages and limitations of established and emerging solutions, with particular attention to their effectiveness in pollutant removal and waste generation. The findings underscore the urgent need for integrated and sustainable emission control technologies, and identify hydrogen-based propulsion and microwave technology or electrochemical systems as promising directions for future development.

Polymer materials are increasingly widely used in high-fire-risk applications, such as aviation interior components. This study aimed to compare the tensile, thermal, and flame-retardant properties of test samples made from ultra-performance materials, polyetherimide (PEI) and polyetherketoneketone (PEKK), using the fused filament fabrication process (FFF). The tensile tests were performed for these materials at different raster angles (0, 45, and 90°). The thermomechanical tests were done in the axial, perpendicular, and through-thickness directions to the extruded filaments. The impact of printing parameters on the flame retardancy of 3D-printed samples was investigated in vertical burn tests with varying specimen thicknesses and printing directions. Experimentally, it was testified that PEKK had better isotropic behaviour than PEI for mechanical performance, thermal expansion, and fire-resistant properties, which are essential in fabricating intricately shaped products.

Purpose Balance allows multidirectional lower limb movements that improve technical football skills and reduce injury caused by match activities. This study aimed to evaluate the static and dynamic balance of preferred and nonpreferred legs during unipedal stance in young footballers and investigate correlations between the two types of balance across each parameter. Methods Forty-three youth players (mean age = 15.81 ± 1.33 years, height = 179.50 ± 6.14 cm, body mass = 69.73 ± 9.35 kg) were involved in this study. Static balance was assessed via ellipse area (EA), perimeter length (P), anterior-posterior deviation (APD), medial-lateral deviation (MLD), trunk deviation (TD), average anterior-posterior speed (AAPS), and average medial-lateral speed (AMLS). The total stability index (TSI) and trunk total deviation (TT D) dynamic parameters were also examined. Results None of the static balance parameters showed significant differences between standing on the preferred and nonpreferred legs. Similarly, no meaningful distinctions were observed between the preferred and nonpreferred legs in terms of dynamic balance parameters. Overall, static and dynamic balances indicated no correlation, although minor connections were found between parameters: TT D and EA (r = 0.332; p = 0.03), TT D and MLD (r = 0.335; p = 0.02), and TT D and TD (r = 0.423; p = 0.01) Conclusions The balance evaluation in young football players should incorporate dynamic and static assessments because the postural control outcomes in these two tasks are independent. Participants underwent testing for both static and dynamic balance, revealing no noticeable differences between their preferred and nonpreferred legs.

Introduction. Despite its importance for sports, the problem of the interaction of genetic and environmental factors affecting sports results in competitions is still not fully understood. This study aimed to evaluate the effect of walking in nature on stress levels and performance of taekwondo athletes during the competition period. Materials and Methods. The participants of this study were 12 Latvian taekwondo athletes, including males (n = 6) and females (n = 6), aged 17-23. The experiment was held four weeks before the International Sweden Taekwondo Competition (2022). The participants underwent twelve training sessions, including 40 minutes of walking in nature, in zones 1 and 2 (HR 101-141 bpm). The Depression and Anxiety Stress Scale questionnaire, gas discharge visualization, and the Determination Test were used to measure the stress levels. The data were analyzed using the mean, standard deviations, the Shapiro-Wilk test, paired sample t-test, and Wilcoxon signed-rank test. Results. The results of the paired sample t-test and Wilcoxon signed-rank test showed that walking in nature significantly affects stress levels ( DASS questionnaire, W = 78.00, as a p-value of 0.002 is < 0.05, gas discharge visualization, t(11) = 8.420, as a p-value of 0.001 is < 0.05, and the Determination Test, t(11) = −5.116, as a p-value of 0.001 is < 0.05) at the 5% level. Conclusions. The findings support visiting natural environments by walking in nature as a potentially helpful activity in taekwondo athletes’ strategy to reduce stress levels. Thus, while coaches may choose different strategies or activities to reduce stress, for many athletes, walking in nature and natural environments helps reduce stress levels.

Abstract Background. Although higher-intensity aerobic interval training (HIIT) is recognized as a modality to attenuate breast cancer (BC) treatment-induced decline in cardiorespiratory endurance and mitigate side effects, it is still really offered as an addition to treatment. Thus, this study investigated the 6-month effects and feasibility of HIIT for BC patients undergoing neoadjuvant chemotherapy (NACT). Methods. Thirty-five women (mean age 47 ± 8 years) diagnosed with stage II-III BC before initial treatment were randomized to either the training group (TG) or non–exercise control group (CG). TG was instructed to perform 4x4 min intervals remotely at an intensity of 85-95% of peak heart rate, 2-3 times a week for 6 months. Treadmill VO2peak and functional performance were assessed before and after the exercise period. Results. After the intervention, TG maintained VO2peak (P=0.94) but decreased in the CG by (13% ± 7%; P<0.001.), a significant difference between the groups with a large effect was absorbed post-intervention (P=0.005). Significant increases were observed (5% ± 4%; P=0.043) in the time to exhaustion for TG while it reduced in CG (9% ± 6%; P=0.003), a significant difference was apparent between the groups post-intervention (P<0.038). Moreover, the TG increased distance in a 6-min walking test (6MWT) by (7% ± 6%; P=0.006), times in a 30-s chair stand test by (19% ± 10%; P=0.003), and 5x sit-to-stand test by (20% ± 14%; P<0.001). Conversely, no changes were observed in the CG in these variables. Significant changes were present between the groups post-intervention 6MWT (P<0.001), 30 – s char stand test (P=0.05), and 5x sit-to-stand test (P=0.015). Conclusion. 6 months of HIIT during NACT is feasible, safe, manageable, and effectively improves cardiorespiratory endurance and functional performance. These results advocate that HIIT should be considered in BC treatment.