The duration of technical elements in rhythmic gymnastics jumps – a longitudinal and correlational study

The research purpose is to identify the development level of some skills/components that condition the execution of Body Difficulties in the group of Jumps/Leaps according to the requirements of the FIG Code of Points and increase the value of technical elements in competition routines. The research was conducted on 14 rhythmic gymnasts, members of the National Junior Team of Romania, and included two stages as follows: the first test took place in December 2019, and the second, in August 2020. Motor and biomechanical information was collected to objectify some motor skills involved in the performance of technical elements specific to the group of Jumps/Leaps. Muscle power, contact times, jump height, flight times and jump rhythm were assessed using the Microgate OptoJump Next device, and the duration of technical elements in the group of Jumps/Leaps was measured by a stopwatch. A programme for the improvement and consolidation of technical elements belonging to this group was applied during the research. Statistical analysis of the collected data required checking the normal distribution of results (using the Skewness and Kurtosis coefficients), identifying the mean differences between the two tests by applying the Student’s t-Test and identifying correlations between the parameters resulting from the two tests using Pearson’s correlation coefficients. Analysing the correlations between the investigated variables for both lower limbs, it can be stated that there is clear evidence of the dependency links between the two symmetrical segments as well as positive and negative correlations between OptoJump variables and the average duration of jumps.

The Associations of Body Image Perception with Serum Resistin Levels in Highly Trained Adolescent Estonian Rhythmic Gymnasts

Rhythmic gymnasts (RGs) are more likely to be dissatisfied with their body mass and shape compared to untrained controls (UCs). However, due to the lack of information, the aim of this study was to investigate the associations of body image perception (BIP) with body composition, daily energy consumption and different blood biochemical markers in adolescent RGs compared to UCs. Thirty-three highly trained RG girls and 20 UC girls aged 14–18 years participated in this cross-sectional study. Height, body mass, body composition, energy intake, resting energy expenditure, training volume and different blood biochemical markers were measured. The body attitude test (BAT) was used to evaluate the BIP of the participants. There were no differences in the total BAT scores between the groups. In RGs, the BAT score correlated positively with the serum resistin level (r = 0.35; p = 0.047). A stepwise multiple regression analysis showed that 40.8% of the variability in the BAT score was determined by resistin and BMI. The association of BIP with resistin values was observed only in RGs. In conclusion, our findings add to the increasing evidence that resistin may be a link between BIP and body composition, most likely through fat mass, in adolescent female RGs.

Effect of plyometric training on dynamic leg strength and jumping performance in rhythmic gymnastics: A preliminary study

BACKGROUND: Reactive performance is an important component of rhythmic gymnastics. So far, it is unclear whether additional plyometric training in female gymnasts shows an increase in performance. OBJECTIVE: The aim of the study was to examine the effect of additional plyometric training in rhythmic gymnastics on the reactive jumping performance and strength of the lower leg muscles. METHODS: Fifteen rhythmic gymnasts (age: 12.3 ± 2.6 years, height: 1.47 ± 0.12 m, body weight: 37.3 ± 9.3 kg, BMI: 16.7 ± 2.1 kg*m-2; competition level: national and international championships, Tanner stages I–III) participated in the study. The athletes were assigned to an experimental (EG) and a control group (CG). The EG performed plyometric exercises three times per week in addition to the regular training. Before and after six weeks of training the reactive jump performance, the work of dorsi flexors and plantar flexors performed during isokinetic plantarflexion, as well as the performance in two sport-specific tests were measured. RESULTS: In contrast to the CG, in the EG the jump height (pre: 24.8; post: 27.25 cm; p< 0.05) and the reactive-strength-index (pre: 1.01; post: 1.19; p< 0.01) increased significantly. The EG achieved significant improvements in the counter movement jump test (pre: 27.0 cm; post: 31.5 cm; p< 0.01) and in the sport specific double rope jump test (jumps per minute, pre: 18.0; post: 23.0; p< 0.01). Furthermore, a significant increase in work performed during plantarflexion was found in the EG for the right leg (pre: 24.9 J; post: 29.7 J; p< 0.01) and a tendency to increase for the left leg (pre: 26.4 J; post: 37.7 J; p= 0.05). CONCLUSION: Both reactive strength and dynamic force can be efficiently increased by plyometric training. It may be recommended to include plyometric exercises in the training regime of rhythmic gymnasts.

Body Composition, Dietary Intake and the Risk of Low Energy Availability in Elite-Level Competitive Rhythmic Gymnasts

The aim of this study was to analyze dietary intake and body composition in a group of elite-level competitive rhythmic gymnasts from Spain. We undertook body composition and nutritional analysis of 30 elite gymnasts, divided into two groups by age: pre-teen (9–12 years) (n = 17) and teen (13–18 years) (n = 13). Measures of height, weight, and bioimpedance were used to calculate body mass index and percent body fat. Energy and nutrient intakes were assessed based on 7-day food records. The two groups had similar percentages of total body fat (pre-teen: 13.99 ± 3.83% vs. teen: 14.33 ± 5.57%; p > 0.05). The energy availability values for pre-teens were above the recommended values (>40 kcal/FFM/day) 69.38 ± 14.47 kcal/FFM/day, while those for the teens were much lower (34.7 ± 7.5 kcal/FFM/day). The distribution of the daily energy intake across the macronutrients indicates that both groups ingested less than the recommended level of carbohydrates and more than the recommended level of fat. Very low intakes of calcium and vitamin D among other micronutrients were also noted. The main finding is that teenage gymnasts do not consume as much energy as they need each day, which explains their weight and development. Moreover, they are at a high risk of developing low energy availability that could negatively impact their performance and future health.

Relationships of Bone Mineral Variables with Body Composition, Blood Hormones and Training Volume in Adolescent Female Athletes with Different Loading Patterns

The aim of this investigation was to determine the relationships of areal bone mineral density (aBMD) and content (BMC) with body composition, blood hormone and training load variables in adolescent female athletes with different loading patterns. The participants were 73 healthy adolescent females (14–18 years), who were divided into three groups: rhythmic gymnasts (RG; n = 33), swimmers (SW; n = 20) and untrained controls (UC; n = 20). Bone mineral and body compositional variables were measured by dual-energy X-ray absorptiometry, and insulin-like growth factor-1 (IGF-1), estradiol and leptin were analyzed from blood samples. In addition, aerobic performance was assessed by a peak oxygen consumption test. No differences (p > 0.05) in weekly training volume were observed between rhythmic gymnasts (17.6 ± 5.3 h/week) and swimmers (16.1 ± 6.9 h/week). Measured areal bone mineral density and bone mineral content values were higher in rhythmic gymnasts compared with other groups (p < 0.05), while no differences (p > 0.05) in measured bone mineral values were seen between swimmers and untrained control groups. Multiple regression models indicated that IGF-1 alone explained 14% of the total variance (R2 × 100) in lumbar spine aBMD, while appendicular muscle mass and training volume together explained 37% of the total variance in femoral neck BMC in the rhythmic gymnast group only. In swimmers, age at menarche, estradiol and appendicular muscle mass together explained 68% of the total variance in lumbar spine BMC, while appendicular muscle mass was the only predictor and explained 19 to 53% of the total variance in measured bone mineral values in untrained controls. In conclusion, adolescent rhythmic gymnasts with specific weight-bearing athletic activity present higher areal bone mineral values in comparison with swimmers and untrained controls. Specific training volume together with appendicular muscle mass influenced cortical bone development at the femoral neck site of the skeleton in rhythmic gymnasts, while hormonal values influenced trabecular bone development at the lumbar spine site in both athletic groups with different loading patterns.

A Longitudinal Study of Bone Mineral Accrual during Growth in Competitive Premenarcheal Rhythmic Gymnasts

The purpose of this investigation was to study whether prolonged competitive rhythmic gymnastics training influenced bone mineral accrual in premenarcheal girls. Eighty-nine girls (45 rhythmic gymnasts [RG] and 44 untrained controls [UC]) between 7 and 9 years of age were recruited and measured annually for four years (not all participants were measured at every occasion). Dual energy x-ray absorptiometry was used to assess the development of whole body (WB), femoral neck (FN) and lumbar spine (LS) bone mineral content (BMC). In addition, body composition, blood adipokine and jumping performance characteristics were obtained. For longitudinal analyses, hierarchical mixed-effects models were constructed to predict differences in the development of WB, FN and LS BMC between RG and UC groups, while accounting for differences in body composition, blood adipokine and jumping performance values. It appeared that from 8 years of age, RG had lower (p < 0.05) fat mass and leptin values, and higher (p < 0.05) jumping performance measures in comparison with UC girls. Hierarchical mixed-effects models demonstrated that RG had 71.9 ± 12.0, 0.23 ± 0.11 and 1.39 ± 0.42 g more (p < 0.05) WB, FN and LS BMC, respectively, in comparison with UC girls. In addition, WB, FN and LS BMC increased more (p < 0.05) between 7 to 12 years of age in RG girls in comparison with UC. In conclusion, these findings suggest that the prolonged exposure to competitive rhythmic gymnastics trainings in premenarcheal girls is associated with greater bone mineral accrual despite lower body fat mass and leptin values.

Efficiency Assessment of Tai Chi Exercises in Physical Rehabilitation of Knee Joint in Young Rhythmic Gymnasts and Choreography Students

Various types of physical activity, including tai chi exercises, have become part of physical rehabilitation of young athletes after knee joint injury. However, many physiological mechanisms of the restorative effect of traditional systems still need to be clarified. We recruited 38 girls aged 10–16 years (mean age 12.5 years, interquartile range [10.8; 13.2] years) involved in different types of physical activity (rhythmic gymnastics and choreography) needing to recover their knee joint function after overuse injury. The subjects were divided into two groups: the main group (physical rehabilitation using a specially developed set of tai chi movements) and the control group (standard course of physical rehabilitation taking place in a physical therapy room). After 2 weeks of rehabilitation, the participants underwent isokinetic testing of the knee joint using the Biodex System 4 Pro (USA). The test results obtained by cluster analysis were typified into three characteristic patterns (χ2 test, p = 0.004): 1) insufficiency of strength parameters (peak torque (PT), peak torque to body mass (PT/BM)) at high speed and insufficiency of functional parameters (PT angle, deceleration time) at high speed; 2) insufficiency of functional parameters (time to PT, deceleration time); 3) insufficiency of strength parameters (PT, PT/BM). It was shown that while the classical means of physical rehabilitation are good for restoring the dynamic muscle parameters (PT), tai chi exercises optimally restore the functional parameters of muscle activation (TP angle and deceleration time). For citation: Vasil’ev O.S., Levushkin S.P., Achkasov E.E., Lyakh V.I., Sharapov A.N. Efficiency Assessment of Tai Chi Exercises in Physical Rehabilitation of Knee Joint in Young Rhythmic Gymnasts and Choreography Students. Journal of Medical and Biological Research, 2021, vol. 9, no. 2, pp. 115–125. DOI: 10.37482/2687-1491-Z049