Barbara Frączek, Andrzej Grzelak and Andrzej Tadeusz Klimek
The purpose of this study was to estimate the daily energy expenditure (DEE) of 30 Polish elite athletes (15 women and 15 men aged 20 to 34 years) representing aerobic-endurance sports and speed-strength sports and to compare the obtained values with energy requirement norms recommended for athletes. Participants’ DEE was measured for seven days using a chronometric-tabular method and a kinematic method. The kinematic method provided significantly lower values of DEE, by 25%. Mean DEEs obtained for female aerobic-endurance and speed-strength athletes were 3042.6 ± 389 and 3255.7 ± 359 kcal/24h (a chronometric-tabular method) and 2230.9 ± 209 and 2346.3 ± 355 (the kinematic method), respectively. The differences between the two groups were not statistically significant (p > 0.05). Male athletes’ mean DEEs were significantly higher (p < 0.05): 3778.0 ± 657 and 4036.7 ± 532 kcal/24h (a chronometric-tabular method) for aerobic-endurance athletes and 2983.3 ± 545 and 2970.4 ± 345 (the kinematic analysis) for speed-strength athletes. As in the case of female athletes, the differences were not significant (p > 0.05). While no evidence was found that the type of sport alone could cause significant differences in the overall mean DEE between aerobic endurance athletes and speed-strength athletes, athletes’ sex significantly differentiated women from men in that respect (the latter’s DEE was significantly greater). Such differences were not noted, though, when athletes’ relative DEE (adjusted for body mass and body composition) were compared. The study revealed that the actual energy requirements of individual athletes can vary in a wide range and that they can be different from recommended energy intake.
Fabio Giuliano Caetano, Vitor Panula da Silva, Ricardo da Silva Torres, Ricardo de Oliveira Anido, Sergio Augusto Cunha and Felipe Arruda Moura
The purpose of this study was to analyse the dynamics of play based on dyads during soccer matches, according to the competition level, period of the matches, and playing positions. We recorded eight Brazilian soccer matches (four of the national and four of the regional level), using up to six digital cameras (30 Hz). The position information of the 204 players in the eight matches was obtained using an automatic tracking system. The Euclidean distance between the nearest opponents was calculated over time to define the dyads. The interaction between the components of dyads was assessed by the distances between players and was compared among the different positions (defender, full-back, defensive midfielder, midfielder, and forward), match periods (15, 30, 45, 60, 75, and 90 min), and competition levels. Results showed smaller distances for the national level dyads, compared to the regional matches. Greater distances between the players were found in the last 15 minutes of the matches, compared to the other periods. The full-backs were more distant from opposing players compared to players from other playing positions. Thus, coaches should consider the characteristics of each playing position and the greater proximity between opponents’ players in top-level competition for the development of tactical proficiency of the players.
Marcos A. Michaelides, Koulla M. Parpa and Anthos I. Zacharia
The purpose of this study was to evaluate abdominal strength in professional soccer players and compare the findings to their lower body strength. An observational design was used to examine abdominal and lower body strength using two functional performance tests (a lower body isokinetic test and an isometric abdominal test, respectively). One hundred and thirty-two professional male soccer players from Cyprus’s first and second divisions participated in this study. Testing included three and twenty-five maximal concentric flexion and extension repetitions at angle speeds of 60°/s (degrees/second) and 300°/s, respectively. On a separate occasion, participants completed two trials on an isometric device (ABTEST Gen. 3 system) for evaluation of abdominal strength. At both isokinetic speeds of 300°/s and 60°/s, abdominal strength had low to moderate significant correlations (p < .05) with quadriceps and hamstring strength. Coefficients of determination (R2) demonstrated that the variability in isokinetic variables accounted for only 14-16% of the variability of abdominal strength. Abdominal strength appears to be high in professional soccer players, but is not dependent on the sports level and/or a playing position. The results of this study demonstrate that abdominal strength and knee joint strength need to be evaluated separately.
Diana Amado, Miryam Maestre, Carlos Montero-Carretero, Pedro Antonio Sánchez-Miguel and Eduardo Cervelló
The current study aimed to evaluate the determinant factors of athletes´ internal positive self-talk that might lead to decreased anxiety and increased performance. The sample consisted of 191 male and female athletes ranging in age from 14 to 35 years old. They played soccer, volleyball and basketball and they were cadets (43%), juniors (29.6 %) and adults (27.4%). Results showed that satisfaction of the basic psychological needs was the strongest predictor of positive self-talk or positive thoughts during competition. Specifically, perception of autonomy was the strongest predictor, because it positively predicted concentration, control of anxiety and instructions, followed by perception of competence, which positively predicted confidence. Finally, team sports coaches should promote perception of autonomy and competence in their athletes, with the aim of enhancing more positive self-talk in competition, which may promote a better performance.
Mirosław Smaruj, Anna Orkwiszewska, Marek Adam, Damian Jeżyk, Maciej Kostrzewa and Radosław Laskowski
The aim of the study was to determine changes in the structure and composition of the body in elite female athletes over a four-year period. The study involved 12 female judo athletes with 34 somatic variables evaluated. Anthropometric evaluation was performed twice, first, when the athletes were members of the national junior team (aged 16.64 ± 1.26 years), and second, after four years, when they were members of the national senior team (aged 20.78 ± 1.27 years). The measurements were taken in accordance with the recommendations of the IBP (International Biological Program) with a set of anthropometric instruments (GPM Swiss) while following the Martin-Saller technique. The average body mass, height, BMI, fat free mass (in kg) and body fat content significantly increased, while the percentage of fat free mass significantly decreased. All of the analyzed body circumferences also increased. Increases were recorded in the width of the upper limbs and they were the width of both hands and both elbows. There was also a statistically significant increase in the value of endomorphic and mesomorphic components, while the ectomorphic component value was similar. Body composition and a substantial number of somatic features of female judokas as seniors were not yet set at the junior stage. The predominant type of the body build was the endo-mesomorphic type and changes that occurred in the sample took place mainly in accordance with this tendency.
Artur Magiera, Robert Roczniok, Ewa Sadowska-Krępa and Katarzyna Kempa
The aim of this study was to determine changes in climbers’ hormonal, cardiovascular, neuromuscular, sleep and fatigue status, and their relationship with performance and workloads during a sport rock climbing camp. Mean difficulty of individual leading climbing routes (mean Difficulty) was calculated for six male, intermediate level sport rock climbers participating in a 2-week camp in Orpierre. Additionally, each morning climbers were tested for: cortisol (d-Cortisol) and testosterone (d-Testosterone) concentrations, testosterone/cortisol ratio (T/C), heart rate and heart rate variability in supine (d-L-HR, d-L-SD1, d-L-SD2) and standing positions (d-S-HR, d-S-SD1, d-S-SD2), difference in S-HR and L-HR (HR-S-L), maximal voluntary hand grip strength (MVC), sleep duration (Sleep) and the self-perception of fatigue (M-Fatigue). Only M-Fatigue and d-Testosterone did not change significantly during the camp. Changes in other variables were large and significant, especially in the second week of the camp when the mean Difficulty was > 70%. The greatest changes were noted on the last day, when T/C, HR-S-L, and Sleep decreased and d-Cortisol, d-L-HR, and d-SD1 increased. The monitoring of the uncoupling of neuromuscular, hormonal, and cardiovascular markers can be instrumental in determining the level of athletes’ morning fatigue and readiness during a climbing camp. An increase in d-Cortisol and a decrease in T/C and HR-S-L are relevant indicators of overreaching in sport climbers.
Few, if any, studies have reported the effects of intensity of balance exercise for balance training and rehabilitation. The aim of the present study was to find a relative measure of intensity of balance exercise. On this basis, we analysed ankle muscle activation in the sagittal plane with increasing difficulty for a one leg stance on a T-board. Ten adults (7 men, 24.1 ± 3.5 years; 3 women, 30.6 ± 5.8 years) performed 3 trials on a T-board within 6 randomly assigned stability levels. T-board swaying velocities in the sagittal plane were manipulated to attain different stability levels (conditions). Concurrently, angular distance of the T-board and active balance time (i.e., percentage of a total time balancing) under each condition were measured. Surface electromyography from the tibialis anterior, gastrocnemius and soleus were monitored during one leg stance. The surface electromyography amplitude in the time domain was quantified using the root-mean-square values. Significant effect of stability levels on angular distance (F5,45 = 3.4; p = 0.01) and velocity of the T-board (F5,45 = 4.6; p = 0.002) were obtained. Active balance time decreased by ∼15% (p = 0.001) from the maximal to the minimal stability conditions. The graded level of balance board stability conditions did not generate significantly higher root-mean-square values in any muscles and hence could not be used as a relative measure of intensity of balance exercise. These findings imply that there could be a plateau in difficulty of balance exercise for enhancement of ankle muscle activity.
Diogo C. F. Silva, Rubim Santos, João Paulo Vilas-Boas, Rui Macedo, António Mesquita Montes and Andreia S. P. Sousa
The lateral ankle sprain is one of the most common sport injury, representing 10-30% of all musculoskeletal disorders. The lateral ankle sprain is induced by sport gestures involving changes of direction and landing manoeuvres and constitutes a risk factor for the occurrence of chronic ankle instability. Although cleat models and performance have been already explored, no study has evaluated this relationship in athletes with chronic ankle instability. Therefore, the purpose of the study was to analyse the influence of different soccer cleat models on Side Hop Test performance of athletes with and without chronic ankle instability. Thirty-nine athletes were divided into two groups, a chronic ankle instability group (n = 20) and a healthy group (n = 19). Each participant performed the Side Hop Test, executing 10 consecutive jumps on dry artificial grass with 4 cleat models. The Qualisys System and two force platforms were used to analyse the test runtime, the distance travelled and the mean velocity. No statistically significant interaction was observed between the group and the cleat model for all variables evaluated. In addition, no differences were observed between models or groups. In this specific test, performance does not seem to be influenced by different cleat models on dry artificial grass in athletes with and without chronic ankle instability.
A. Rui Gomes, Clara Simães, Olga Dias, Catarina Almeida and Sónia Gonçalves
There is mixed evidence for the relationship between increased levels of the drive for muscularity (DFM) and disordered eating behavior in males, therefore this study analysed the relationship between DFM and disordered eating behavior, giving particular relevance to the patterns of cognitive appraisal. A convenience sample was recruited from fitness centres and sport clubs with 308 participants, all males. Losing muscular mass represented a negative experience for participants, promoting a higher perception of threat appraisal. In addition, losing muscular mass was related to more muscularity-oriented behaviors and disordered eating behavior. Cognitive appraisal mediates the relation between DFM and disordered eating behavior. The results highlight the role of cognitive appraisal in DFM and disordered eating behavior in males in sport contexts.
Marian Rzepko, Sławomir Drozd, Patrycja Żegleń, Paweł Król, Wojciech Bajorek and Wojciech Czarny
The aim of this study was to evaluate the effects of training experience in wrestling on postural control. Fourteen elite athletes with at least 8 years of wrestling training and competition experience participated in the study. The control group consisted of fifteen healthy adults who were not competitive athletes. The center of pressure (COP) trajectories were recorded with the use of an AMTI force plate at a sampling frequency of 50 Hz. The rambling-trembling decomposition method was used to analyze the COP trajectory data. The main finding was a significant effect of training experience on postural control in only the sagittal plane. Interestingly, significant differences in velocity were observed for the trembling component of the COP. All described variables were significantly higher in wrestlers. We hypothesized that balance training may lead to task-specific neural adaptations at the spinal and supraspinal levels. It was concluded that further research of high methodological quality is needed to determine the effect of training experience on balance control in elite athletes. Additionally, this effect should be observed in youth athletes, as it may be treated as a selection criteria in the training process.