The main aim of this study was to compare anthropometric and physical fitness indicators of boys of the same chronical age but with different fat percentages. Subjects were Hungarian boys aged 9–13 years (N = 6919). Anthropometry was measured according the guidelines of the International Biological Program. Relative body fat was estimated by Drinkwater–Ross’s method (1980); Conrad’s growth type of physique was also estimated (1963). Physical fitness was tested with 30 m dash (s), standing long jump (cm), fistball throw (m), and 1200 m run (s). Subjects of each cohort were grouped into seven subgroups with fat percentage ranges of 4%. Differences between subgroups were tested by one-way ANOVA. In the case of a significant F-test, Tukey’s post-hoc tests were used. The level of effective random error was set at 5% in all significance tests (p < 0.05). Except for the three groups with low fat percentages, values of body weight, stature, body mass index, and plastic and metric indexes were significantly higher; results of 30 m, 1200 m running, and standing long jump were worse in all groups with higher fat percentages. An interesting finding of the current study is that body fat percentage also influenced the physical fitness of non-overweight and obese children as well when using merely the 4% ranges in grouping by fatness. The lower the fat the better the physical fitness was in this sample of pre- and peripubertal boys.
Background: Continuously rising performances in elite adolescent athletes requires increasing training loads. This training overload without professional monitoring, could lead to overtraining in these adolescents. Methods: 31 elite adolescent athletes (boys: n = 19, 16 yrs; girls: n = 12, 15 yrs) participated in a field-test which contained a unified warm-up and a 200 m maximal freestyle swimming test. Saliva samples for testosterone (T) in boys, estradiol (E) in girls and cortisol (C) in both genders were collected pre-, post- and 30 min post-exercise. Lactate levels were obtained pre- and post-exercise. Brunel Mood Scale, Perceived Stress Scale and psychosomatic symptoms questionnaires were filled out post-exercise. Results: Lactate levels differed between genders (boys: pre: 1.01 ± 0.26; post: 8.19 ± 3.24; girls: pre: 0.74 ± 0.23; post: 5.83 ± 2.48 mmol/L). C levels increased significantly in boys: pre- vs. post- (p = 0.009), pre- vs. 30 min post-exercise (p = 0.003). The T level (p = 0.0164) and T/C ratio (p = 0.0004) decreased after field test which draws attention to the possibility of overtraining. Maximal and resting heart rates did not differ between genders; however, heart rate recovery did (boys: 29.22 ± 7.4; girls: 40.58 ± 14.50 beats/min; p = 0.008). Conclusions: Our models can be used to explain the hormonal ratio changes (37.5–89.8%). Based on the results this method can induce hormonal response in elite adolescent athletes and can be used to notice irregularities with repeated measurements.
Backround: Osteoporosis is a common disease and physical activity (PA) has a favourable influence on bone status. Aim: To establish normative data for calcaneal quantitative ultrasound (QUS) bone characteristics in children and to analyse the relationships between PA, anthropometric and bone parameters. Subjects and methods: Hungarian children aged 7–19 (n = 2674; 1325 girls, 1349 boys) provided PA, anthropometric and bone data. QUS parameters were registered with Sonost3000 densitometer (speed of sound: SOS, m/s; broadband ultrasound attenuation: BUA, dB/MHz; bone quantity index (BQI = αSOS + βBUA). Reference centiles of QUS parameters were constructed by LMS method. Multivariate linear regression models were used to analyse the relationships. Results: QUS bone parameters increased with age. There were no gender differences, except in 11- and 19-year-old children, where boys showed higher values. SOS (1497.15 ± 15.72 vs 1494.05 ± 14.81 m/s) and BQI (65.31 ± 16.71 vs 62.26 ± 15.78) were higher in athletic children. The regression model revealed significant relations between SOS and age, relative muscle mass and PA; BUA correlated with gender, morphological age, BMI, relative muscle mass and PA. Conclusions: Changes in the bone parameters among 7–19-year-old Hungarian children depended on age, anthropometric dimensions and the level of PA. The normative data could be used for monitoring QUS bone parameters in children, leading to more effective interventions for healthy bones.
Background: Regular sport has favourable influence on the physical and mental state. Our aim was to analyse the relationship between regular sport activities, body parameters, cortisol level, perceived stress and the frequency of psychosomatic symptoms in male and female university students. Methods: Subjects were university students (N = 200). They were divided in sporting (more than 7 h week−1: 56 males (sm), 50 females (sf)) and non-sporting (less than 3 h week−1: 44 males (nsm) and 50 females (nsf)) groups. Body composition was estimated by Inbody720-analyser. Stress levels were measured by (1) free cortisol level in saliva measured by using IBL-ELISA kits and (2) questionnaires about psychosomatic symptoms and perceived stress scale. Results: There were significant subgroup’ differences in body composition (fat%:sm:12.1 ± 6.0 vs. nsm:17.9 ± 6.8; sf:20.8 ± 5.5 vs. nsf:25.4 ± 5.7; muscle%:sm:50.3 ± 3.6 vs. nsm:47.6 ± 3.9; sf:43.8 ± 3.2 vs. nsf:41.7 ± 3.3), and in stress level (total scores:sm:21.0 ± 5.7 vs. nsm:23.3 ± 7.2; sf:25.5 ± 7.0 vs. nsf:28.0 ± 9.7). There were gender differences in the psychosomatic symptoms' frequency (total scores: sm: 14.6 ± 6.3 vs. sf: 20.4 ± 7.4; nsm: 14.9 ± 6.1 vs. nsf: 19.6 ± 8.2). The sporting students had larger muscle, smaller fat percentages, and lower level of stress. Basic level of salivary cortisol revealed significant relation with physical activity: sporting students had lower level of cortisol. This relation was reflected in higher percentage of students with low level of cortisol in the physically active subgroups (s/ns males: 29% vs. 15%; s/ns females: 18% vs. 5%) and in the higher percentage of female students with high level of cortisol in the non-sporting subgroup (27% vs. 11%). Conclusion: Regular sport activity is positively related with lower stress levels in university students.
30 March 2019 in Central European Journal of Public Health
Objectives: Physical activity (PA) and adequate macro- and micronutrient intake have favourable influence on the bone status. The aim of this study was to analyse the relationships among PA, anthropometric data, dietary intake and ultrasound b...
Background: The purpose of our study was to compare the physiological effects of extreme physical and psychological stress tests in male soccer players, since these two types of stress apply to athletes with high performance requirements. Methods: A total of 63 healthy male soccer players participated in this study, all of whom underwent both of the tests. A physical stress test was carried out in an exercise physiology laboratory, where subjects completed an incremental treadmill running test to full exhaustion, and a psychological test was performed in a military tactical room, where subjects met a street offence situation. Heart rate variability (HRV) and blood pressure (BP) were recorded directly before, immediately after, and 30 min after the stress tests. Results: The majority of HRV indices changed significantly in both stress protocols. Inverse, significant changes (positive for the physical test, negative for the psychological test, p < 0.001) were found when comparing the alterations of HRV indices between the tests. Significant differences were found in the changes in systolic (p = 0.003) and diastolic (p < 0.001) BP between the test protocols, and also between the baseline and post-test measurements (p < 0.001). Conclusion: Both HRV and BP are sensitive physiological parameters to measure the impact of extreme physical and/or psychological stress