This study explores the association of respiratory muscle strength with aerobic endurance kinetics among athletes, with a specific focus on maximal oxygen consumption (VO₂max). Previous research has elucidated the complex interactions between respiratory and skeletal muscles during exercise, highlighting the critical role of efficient respiration in maximizing athletic performance. The interplay between active skeletal muscles and respiratory muscles, especially the influence of respiratory muscle fatigue on exercise capacity, is well-documented. High-intensity exercise has been shown to activate the respiratory muscle metaboreflex, which can restrict blood flow to working muscles, thereby impacting the energy required for respiration. A total of 41 athletes, drawn from the disciplines of biathlon, judo, and cross-country, participated in this study. Respiratory function tests (RFTs) were administered to assess various respiratory parameters, including changes in chest circumference. Additionally, maximal oxygen consumption (VO₂max) and heart rate were measured during a treadmill test. To explore the associations between VO2max and ventilatory parameters—namely, ventilation (VE), oxygen consumption (VO₂), carbon dioxide production (VCO₂)—as well as respiratory metrics, linear regression analysis was employed. Based on the standardized regression coefficients (β), it was found that maximum expiratory pressure (MEP) (mean ± SD: 130.95 ± 42.82) and inspiratory diaphragmatic circumference values were significantly associated with VE, VO₂, and VCO₂. Conversely, the other predictor variables did not exhibit a significant effect on VE (mean ± SD: 134.80 ± 36.69), VO₂ (mean ± SD: 3877.52 ± 868.47 mL), and VCO₂ (mean ± SD: 4301.27 ± 1001.07 mL). Similarly, measurements of chest circumference (mean ± SD: 91.40 ± 10.72 cm), MEP, and diaphragmatic circumference during inspiration (mean ± SD: 95.20 ± 10.21 cm) were significantly associated with VO₂max (mean ± SD: 58.52 ± 10.74 mL/kg/min), while the remaining predictor variables did not demonstrate a significant effect on VO₂max. Additionally, a multiple linear regression analysis was conducted to examine the combined effects of respiratory muscle strength and ventilatory factors on VO₂max. The model, which included interaction terms, explained 89.9% of the variance in VO₂max (R² = 0.899, adjusted R² = 0.859). Significant interactions were found between MIP and VE (B = −0.084, p = 0.006), as well as MEP and VE (B = 0.072, p = 0.012). These findings suggest that respiratory muscle strength plays a more substantial role in determining VO₂max in individuals with higher ventilatory efficiency, highlighting the importance of both respiratory strength and breathing efficiency in aerobic performance. Our findings underscore the importance of considering respiratory muscle strength in assessing and enhancing athletes’ aerobic performance. Integrating objective measurements such as maximal inspiratory and expiratory pressure assessments into routine performance evaluations allows coaches and sports scientists to monitor changes in respiratory function over time and adjust training protocols accordingly.

Background and Study Aim. The aim of this study was to examine the effect of a 6-week plyometric training program on agility, vertical jump, squat jump, and speed performance in soccer players. Material and Methods. A total of 26 male soccer players actively playing for Ankara Batıkent Kartal Sports Club participated in the study as volunteers. The players had an average age of 15.04 ± 0.16 years, an average height of 172.48 ± 5.14 cm, and an average body weight of 62.65 ± 0.38 kg. Data on the players' gender, age, body weight (kg), height (cm), body mass index (BMI), agility, vertical jump (cm), squat jump, and 30 m speed were obtained. Statistical analysis was performed using SPSS 25 software. The normality of the data was examined using the Shapiro-Wilk test. Paired samples t-test was used to determine within-group differences, and independent samples t-test was used to determine differences between groups. A statistical significance level of p < 0.05 was considered for all evaluations. Results. The plyometric training program was effective in improving agility, vertical jump, squat jump, and speed performance in the experimental group. There was a significant difference in agility and 30 m speed values in the pre-test and post-test evaluations of the Control group, but no difference was observed in vertical jump and squat jump values. Additionally, in the pre-test and post-test comparison between the experimental and control groups, a significant difference was observed in agility, vertical jump, and squat jump values. However, no significant difference was found in 30 m speed values. Conclusions. That plyometric training program is effective in improving agility, vertical jump, squat jump, and 30 m speed values.

Background: Repeated sprint ability (RSA) is defined as the ability to recover and maintain maximal effort during repeated sprints, recognised as a crucial performance component in team sports. The exercise mode used to test RSA may influence performance and the contributions of different energy systems. The primary aim of this study is to address the critical gap between traditional cycling-based anaerobic tests, such as the Wingate test, and the practical, sport-specific demands of running in field-based team sports. Methods: This study involved 32 professional soccer players (age: 21.2 ± 1.3 years; height: 177.8 ± 4.3 cm; and mass: 71.3 ± 6.4 kg). They performed cycling- and running-based repeated sprint tests, with similar total sprint numbers, durations, and recovery times, on different days. Contributions from adenosine triphosphate-phosphocreatine (ATP-PCr), glycolytic, and oxidative systems were estimated through body weight, oxygen uptake (VO₂), blood lactate (BLa), and the fast component of excess post-exercise oxygen consumption (EPOC). The VO₂ levels and heart rate (HR) were monitored during the rest (10 min), exercise, and recovery (15 min) phases in a breath-by-breath mode using a portable gas exchange system. BLa was measured before (at rest) and 1, 3, 5, 7, and 10 min after the running and cycling tests using a handheld portable analyser. A mono-exponential model estimated the ATP-PCr system contribution, calculated using the fast component of EPOC following the final sprint and the sum of the VO₂-time integral during rest intervals. Results: The cycling tests demonstrated significantly higher values for the peak power (PP), mean power (MP), and rate of perceived exertion (RPE) (p < 0.05), while the heart rate peak and blood lactate responses were similar across all modalities. The fatigue index was notably higher in the running tests (p < 0.05). Furthermore, the running tests showed greater contributions in both the percentage and absolute terms from the adenosine triphosphate-phosphocreatine (ATP-PCr) system (p < 0.01), total energy demand (p < 0.05), and total energy expenditure (TEE) (p < 0.01). Notably, the running tests resulted in an increased phosphocreatine breakdown (p < 0.05) and rapid phosphocreatine replenishment (p < 0.01). A simple linear regression analysis highlighted a significant determination coefficient between these performance variables and the contributions of the energy systems, affirming the robustness of the results. The correlation heatmaps further illustrated these relationships, with higher correlations for the PP and MP across modalities (0.41), emphasising the moderate association between cycling and running tests in these metrics. Conclusions: This study elucidated the similarities and differences in energy system contributions and performance outcomes between a cycling and a running repeated sprint protocol, with a comparable total sprint time and work–rest ratio. The findings reveal that a running repeated sprint test elicits a higher energy demand and a higher contribution from the PCr energy system compared to cycling. Performance variables were not associated between running and cycling tests, suggesting those tests cannot be used interchangeably.

The aim of this study was to compare energy system contributions and examine the relationship between mechanical variables and energy system variables in lower body Wingate tests, with a focus on gender differences. A total of thirty martial artists participated in the study. Participants performed 30-second lower body Wingate tests. Mathematical methods were used to estimate the contributions of the oxidative, glycolytic and ATP-PCr pathways based on lactate levels and oxygen consumption kinetics during rest, exercise and recovery. The main results showed that in men the relative contributions of the oxidative, glycolytic and ATP-PCr pathways were 16%, 37% and 47% respectively. In women the relative contributions for the same pathways were 16%, 38% and 46% respectively. In men the total energy expenditure and the absolute contributions of the oxidative, glycolytic and ATP-PCr pathways were 132 kJ, 22 kJ, 49 kJ and 61 kJ, respectively. In women these values were 106 kJ, 17 kJ, 41 kJ and 49 kJ. Although the relative energy contributions were similar, men had higher total energy expenditure and absolute energy contributions than women. In addition, men had higher absolute and relative power outputs than women, while showing similarities in fatigue index, lactate levels, heart rate and perceived exertion ratings. The ATP-PCr pathway was able to explain the variation in mechanical variables in both male and female participants. The results suggest that the contribution of energy systems, physiological responses and performance variables varies according to gender.

The aim of the current study is to examine the effect of nutrition education on the eating behaviors, eating awareness and sports nutrition knowledge of adolescent football players. The sports nutrition education module and the educational model to be used were developed by the researchers based on examples from sports nutrition books. The athlete questionnaire included sections on demographic information and eating habits. In addition, the eating awareness scale, the adolescent eating behavior perception scale and the athlete nutrition knowledge level test were administered to the athletes before and after the training. Twenty-five male soccer players aged 15-17 were included in the study. The six-week athlete nutrition training was delivered face-to-face by the researchers. After data collection, the SPSS 23.0 software package was used for statistical analysis. When the athletes’ nutritional habits were examined, significant improvements were found in post-training eating times (p

Background and Study Aim. The prediction of running anaerobic sprint test and 800 m performance by parameters of critical velocity was examined in this study. Material and Methods. The participants of study were consisted of thirteen amateur soccer players (n=13, age=22.69±5.29 years, weight=72.46±6.32 kg, height=176.92±6.73 cm). The 800 and 2400 m running tests were performed for determination of critical velocity and anaerobic distance capacity. The critical velocity and anaerobic distance capacity were determined by three mathematical models (linear total distance, linear velocity, non-linear two parameter model). The repeated sprint and sprint endurance ability was determined by running anaerobic sprint test and 800 m running test. The simple and multiple linear regression analysis was used for prediction of dependent variables (running anaerobic sprint test and 800 m running performance) by independent variables (critical velocity and anaerobic distance capacity) of study. The correlation between variables was determined by Pearson correlation coefficient. Results. It was found that anaerobic distance capacity was a significant predictor of running anaerobic sprint test and 800 m running performance (p˂0.05). However, it was determined that critical velocity predicted significantly only time parameters of running anaerobic sprint test and 800 m test (p˂0.05). Also, the parameters of 800 m test (except for average velocity) were significantly predicted by running anaerobic sprint test parameters (p˂0.05). Conclusions. It may be concluded that anaerobic distance capacity is an indicator of repeated sprint and speed endurance ability in soccer and may be used in improvement of sprint endurance performance. Передумови та мета дослідження. У цьому дослідженні було розглянуто прогноз результатів бігового тесту на анаеробний спринт і бігу на 800 м по параметрам критичної швидкості.Матеріал і методи. У дослідженні взяли участь тринадцять футболістів-аматорів (n = 13, вік 22,69 ± 5,29 року, вага 72,46 ± 6,32 кг, зріст 176,92 ± 6,73 см). Бігові випробування на 800 і 2400 м було проведено для визначення критичної швидкості і потенційного анаеробного відстані. Критична швидкість і довжина анаеробного відстані визначалися за допомогою трьох математичних моделей (лінійне загальна відстань, лінійна швидкість, нелінійна двопараметричного модель). Здатність до повторного спринту і спринтерській витривалості визначалася за допомогою тесту на анаеробний спринт і тесту бігу на 800 м. Простий і множинний лінійний регресійний аналіз використовувався для прогнозування залежних змінних (тест на анаеробний спринт і біг на 800 м) по незалежним змінним (критична швидкість і потенціал анаеробної дистанції) дослідження. Кореляція між змінними визначалася коефіцієнтом кореляції Пірсона.Результати. Було виявлено, що потенціал анаеробної дистанції був значущим предиктором результатів тесту на анаеробний спринт і результатів бігу на 800 м (p = 0,05). Однак було встановлено, що критична швидкість достовірно передбачала тільки тимчасові параметри бігового тесту на анаеробний спринт і тесту на 800 м (p˂0,05). Крім того, параметри тесту на 800 м (за винятком середньої швидкості) були значно передбачені при виконанні параметрів тесту анаеробного спринту (p = 0,05).Висновки. Можна зробити висновок, що потенціал анаеробної дистанції є показником здатності до повторного бігу і швидкісної витривалості в футболі і може бути використана для поліпшення показників витривалості в спринті. Предпосылки и цель исследования. В этом исследовании был рассмотрен прогноз результатов бегового теста на анаэробный спринт и бега на 800 м по параметрам критической скорости.Материал и методы. В исследовании приняли участие тринадцать футболистов-любителей (n = 13, возраст 22,69 ± 5,29 года, вес 72,46 ± 6,32 кг, рост 176,92 ± 6,73 см). Беговые испытания на 800 и 2400 м были проведены для определения критической скорости и потенциального анаэробного расстояния. Критическая скорость и длина анаэробного расстояния определялись с помощью трех математических моделей (линейное общее расстояние,...