Energy cost and energy sources of an elite female soccer player to Repeated Sprint Ability Test: a case study

Background: Intense physical efforts performed at maximal or near-maximal speeds and the ability to recover among sprint are important characteristics of a soccer player. In the last years, women's soccer has become a rapidly and markedly growing sport (+34% of new players from 2000). Objective: The aim of this case study was to analyse the performance (total time –TT; fatigue index percentage-IF%) and physiological (aerobic and anaerobic) responses to Repeated Sprint Ability test (RSAt) of an elite female player. Methods: To identify the contribution of the 3 energy sources at the beginning, middle, and at the end of the different sprint of RSAt performance in a female player (age: 30 years; BMI: 20.3 kg/m 2 ), which requested 7x30 m sprints (25 s active recovery among sprints) with a change of direction, a portable metabolimeter and software dedicated were used. A repeated measure MANOVA over the 7 sprints time series was applied (p< 0.05). Results: Results showed that TT was 58.71 s (Ideal Time: 56.98 s) with IF% of 3.0%. Energy contributions were given for 80.3% by aerobic, 19.2% by anaerobic lactid, and 0.5% by anaerobic alactid sources. We have found different kinetics in the heart rate (HR) and maximum oxygen uptake with the oxygen uptake that reached the peak when HR was still rising. Conclusion: Considering that the energy consumption during intermittent exercises requires different metabolism as a result of physiological stimuli proposed, the present findings substantiate the need to choose specific and adequate training methods for female soccer players that aim at increasing their RSA performances. © 2019 Perroni et al

Gender differences in anthropometric parameters and technical performance of youth soccer players

Considering that the popularity and professionalism of females soccer has increased markedly, the aims of this study were to evaluate the eventual (1) technical differences between the young male and female soccer players, and (2) relationship among anthropometrics characteristic (weight, height and Body Mass Index), soccer experiences, and soccer performances (juggling, speed dribbling, long and short passing, shooting from dead ball and from a pass; heading) in 16 female and 32 male soccer players (n: 48; age: 16 ± 1 years; BMI 20.8 ± 2.0 kg/m2). Unpaired student t test was applied to assess differences between groups (male vs female) to variables with normal distribution (age, height, weight, BMI, speed dribbling without ball, short pass), while Mann–Whitney U test was applied to the other non-parametric variables. Spearman Rho correlation was used to analyse relationships among variables considering all subjects, male, and female categories. Results showed differences (p < 0.05) between groups for height (p < 0.0001), weight (p = 0.0002), juggling foot–chest–head (p = 0.03), speed dribbling with (p = 0.01), and without (p < 0.05) ball. Correlations between variables were found in all subjects, female and male groups. Female soccer players showed better values than males in juggling test but worse in speed dribbling with ball and in shooting. Considering gender differences in soccer performance, cut-off used for male cannot apply to female because utilization of the same exercise and/or application of the same training volume might cause poor training effect

Carbohydrate intake in adolescent cyclists : habitual intake, endurance performance and gastric emptying

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Validity and reliability of GYKO inertial sensor system for the assessment of ROM of elbow.

BACKGROUND: The evaluation of joints range of motion (ROM) represents a fundamental step in the diagnosis of joint disorders. Assessors usually measure the ROM angle through a universal goniometer (UG). GYKO inertial system (Microgate, Bolzano, Italy) represent a noninvasive, easy-to-use, Inertial Measurement Unit (IMU) method for the measurement of the elbow ROM. The aim of this study was to validate the GYKO digital device comparing it with the gold standard UG in the measurement of elbow flexion-extension ROM in healthy subjects. METHODS: Thirty healthy subjects (15 females, 15 males; mean age: 34 years, range 25-58 years) were enrolled. The elbow ROM of the dominant arm was measured with two methods, UG and GYKO. Active flexion-extension movement of the elbow was measured by two operators with UG (A1_UG; A2_UG) and with GYKO (A1_GYKO; A2_GYKO; B_GYKO). Intra-rater reliability, inter-rater reliability, and concurrent validity were analyzed by intraclass correlation coefficient (ICC) values. Bland-Altman plot was used to compare UG and GYKO. RESULTS: Both methods were very reliable (P<0.001). Intra-rater reliability showed strong correlation respectively for the UG (ICC=0.798) and for GYKO (ICC=0.859) while inter-rater reliability showed moderate correlation with UG (ICC=0.726) and strong correlation with GYKO (ICC=0.942). The concurrent validity, obtained by three comparisons (A1, A2 and B) showed moderate correlation (ICC: 0.576-0.776). CONCLUSIONS: The results of this study support the use of GYKO as useful as the UG for the assessment of the active flexion-extension ROM of the elbow

Cortisol, dehydroepiandrosterone sulphate and dehydroepiandrosterone sulphate/cortisol ratio responses to physical stress in males are influenced by pubertal development

To evaluate the influence of chronological age and pubertal development on the hypothalamus-pituitary-adrenal (HPA) axis response to stress, we studied the possible correlations between male pubertal characteristics and salivary cortisol (C), DHEAS and the DHEAS/C ratio before (pre-stress) and after acute exercise-stress in young male volunteers (no. 87; 13.3+/-2.1 yr). In our overall study population, the mean pre-stress salivary C and DHEAS concentrations, significantly increased after exercise-related stress, whereas the DHEAS/C ratio significantly decreased. Pre-stress salivary C was positively correlated with chronological age, and after-stress salivary C concentration variations were negatively correlated with pubertal stage, mean testis volume and pre-stress salivary DHEAS. Furthermore, salivary DHEAS concentrations and the DHEAS/C ratio, before and after exercise stress, were positively correlated with chronological age, pubertal stage, pre-stress salivary testosterone (T), testis volume and body mass index (BMI). In contrast with late pubertal stages (P4, P5), young individuals at early stages of puberty (P1 to P3) showed higher C increase and lower DHEAS/C ratio after exercise-related stress. In conclusion, since C is also a mediator of stress-related negative effects on health and the DHEAS/C ratio has been hypothesized as an index for the degree to which an individual is buffered against the negative effects of stress, these data might suggest potentially increased stress-related risks at early stages of male puberty