Ballet dancing is a multifaceted activity requiring muscular power, strength, endurance, flexibility, and agility; necessitating demanding training schedules. Furthermore dancers may be under aesthetic pressure to maintain a lean physique, and adolescent dancers require extra nutrients for growth and development. This cross-sectional study investigated the nutritional status of 47 female adolescent ballet dancers (13–18 years) living in Auckland, New Zealand. Participants who danced at least 1 hr per day 5 days per week completed a 4-day estimated food record, anthropometric measurements (Dual-energy X-ray Absorptiometry) and hematological analysis (iron and vitamin D). Mean BMI was 19.7 ± 2.4kg/m2 and percentage body fat, 23.5 ± 4.1%. The majority (89.4%) of dancers had a healthy weight (5th-85th percentile) using BMI-for-age growth charts. Food records showed a mean energy intake of 8097.3 ± 2155.6kJ/day (48.9% carbohydrate, 16.9% protein, 33.8% fat, 14.0% saturated fat). Mean carbohydrate and protein intakes were 4.8 ± 1.4 and 1.6 ± 0.5g/kg/day respectively. Over half (54.8%) of dancers consumed less than 5g carbohydrate/kg/day, and 10 (23.8%) less than 1.2 g protein/kg/day. Over 60% consumed less than the estimated average requirement for calcium, folate, magnesium and selenium. Thirteen (28.3%) dancers had suboptimal iron status (serum ferritin (SF) <20μg/L). Of these, four had iron deficiency (SF < 12μg/L, hemoglobin (Hb) ≥ 120g/L) and one iron deficiency anemia (SF < 12μg/L, Hb < 120g/L). Mean serum 25-hydroxy vitamin D was 75.1 ± 18.6nmol/L, 41 (91.1%) had concentrations above 50nmol/L. Female adolescent ballet dancers are at risk for iron deficiency, and possibly inadequate nutrient intakes.
Kathryn L. Beck, Sarah Mitchell, Andrew Foskett, Cathryn A Conlon and Pamela R. Von Hurst
Jonathan M. Taylor, Tom W. Macpherson, Shaun J. McLaren, Iain Spears and Matthew Weston
To compare the effects of 2 repeated-sprint training programs on fitness in soccer.
Fifteen semiprofessional soccer players (age: 24 ± 4 y; body mass: 77 ± 8 kg) completed 6 repeated-sprint training sessions over a 2-week period. Players were assigned to a straight-line (STR) (n = 8; 3–4 sets of 7 × 30 m) or change of direction (CoD) (n = 7; 3–4 sets of 7 × 20-m) repeated-sprint training group. Performance measures included 5-, 10-, and 20-m sprints, countermovement jump, Illinois agility, and Yo-Yo Intermittent Recovery Test level 1 (YYIRTL1) performance. Internal (heart rate) and external (global positioning system-derived measures) training loads were monitored throughout. Data were analyzed using magnitude-based inferences.
Internal and external loads were higher in the STR group than in the CoD group with large differences in maximum velocity (28.7%; ±90% confidence limits, 3.3%), moderate differences in mean heart rates (7.0%; ±1.4%) and PlayerLoad (17.6%; ±8.6%), and small differences in peak heart rates (3.0%; ±1.6%). Large improvements in 5-m (STR: 9.6%; ±7.0% and CoD: 9.4%; ±3.3%), 10-m (STR: 6.6%; ±4.6% and CoD: 6.7%; ±2.2%), and 20-m (STR: 3.6; ±4.0% and CoD: 4.0; ±1.7%) sprints were observed. Large and moderate improvements in YYIRTL1 performance were observed in the STR (24.0%; ±9.3%) and CoD (31.0%; ±7.5%), respectively. Between-groups differences in outcome measures were unclear.
Two weeks of repeated-sprint training stimulates improvements in acceleration, speed, and high-intensity running performance in soccer players. Despite STR inducing higher internal and external training loads, training adaptations were unclear between training modes, indicating a need for further research.
Oliver Faude, Anke Steffen, Michael Kellmann and Tim Meyer
To analyze performance and fatigue effects of small-sided games (SSG) vs high-intensity interval training (HIIT) performed during a 4-wk in-season period in high-level youth football.
Nineteen players from 4 youth teams (16.5 [SD 0.8] y, 1.79 [0.06] m, 70.7 [5.6] kg) of the 2 highest German divisions completed the study. Teams were randomly assigned to 1 of 2 training sequences (2 endurance sessions per wk): One training group started with SSG, whereas the other group conducted HIIT during the first half of the competitive season. After the winter break, training programs were changed between groups. Before and after the training periods the following tests were completed: the Recovery-Stress Questionnaire for Athletes, creatine kinase and urea concentrations, vertical-jump height (countermovement jump [CMJ], drop jump), straight sprint, agility, and an incremental field test to determine individual anaerobic threshold (IAT).
Significant time effects were observed for IAT (+1.3%, ηp 2 = .31), peak heart rate (–1.8%, ηp 2 = .45), and CMJ (–2.3%, ηp 2 = .27), with no significant interaction between groups (P > .30). Players with low baseline IAT values (+4.3%) showed greater improvements than those with high initial values (±0.0%). A significant decrease was found for total recovery (–5.0%, ηp 2 = .29), and an increase was found for urea concentration (+9.2%, ηp 2 = .44).
Four weeks of in-season endurance training can lead to relevant improvements in endurance capacity. The decreases in CMJ height and total-recovery score together with the increase in urea concentration might be interpreted as early signs of fatigue. Thus, the danger of overtaxing players should be considered.
Morphological parameters (stature, weight, segment lengths, diameters, circumferences, body composition), functional characteristics (work capacity, respiratory performance, static strength of hand) and aspects of health- and skill-related fitness (explosive strength, speed, anaerobic and aerobic endurance, agility) of 141 well-trained young female field hockey players (10 to 18 y) were examined and analyzed. The main purpose of the investigation was to study growth trends of these parameters of female field hockey players and to analyze the character and feature of their development.
Standard anthropometric measurements were used for evaluation of morphological characteristics. Matiegka’s equations were used for computation of body composition’s parameters. Modification of the Harvard step test was used for estimation of physical capacity. Respiratory performance was evaluated using vitalograph. Static strength of the hands was obtained using a handgrip. Characteristics of health- and skill-related fitness were evaluated using the following test battery: standing broad jump, 30 m dash run, flying 30 m test, 210 yards shuttle run, 2000 m run, push-ups and 20 m zig-zag run.
Results of the study were as follows: the functional characteristics have the greatest total increase (about 108-144 %) during the age span considered (from 10 to 18 years). Stature and other length parameters increased about 18-20 %. The periods of the acceleration of increases in morphological parameters precede the periods of the sizable increases in functional parameters. Based upon the analysis of aspects of health- and skill-related fitness of players training and practicing in hockey has a beneficial effect on this group of characteristics. Based on the results of the study, the optimum periods for speed, strength and endurance training of female hockey players are exposed.
Jeffrey R. Doeringer, Megan Colas, Corey Peacock and Dustin R. Gatens
cold-water immersion affected an athlete’s postexercise recovery on muscle performance or pain perception. More specifically, looking at muscle performance included flexibility, power, speed, and agility, similar to what is required for completing a sport task. We hypothesized that cold-water immersion
Zakariya Nawasreh, David Logerstedt, Adam Marmon and Lynn Snyder-Mackler
(<7 mo) between the ages 14 and 55 years were enrolled into this study; 9 of them completed 10 sessions of mechanical perturbation training (mechanical group) using the Reactive Agility System (Simbex LLC, Lebanon, NH). Another 9 patients were matched for age and sex using data from patients who
John Cairney, Heather Clark, Dean Dudley and Dean Kriellaars
literacy; mot = motor; percomp = perceived competence; enjoy = enjoyment; motiv = motivation; speed = running speed and agility; streng = strength; bal = balance; bicor = bilateral coordination; vmot = visual motor control; ucor = upper limb coordination; uspeed = upper limb speed and agility; res
Robyn F. Madden, Kelly A. Erdman, Jane Shearer, Lawrence L. Spriet, Reed Ferber, Ash T. Kolstad, Jessica L. Bigg, Alexander S.D. Gamble and Lauren C. Benson
10 on-ice hockey SP tests, including forward and backward sprints, reaction, weave agility, and transition agility. 17 All tests were timed with and without a puck, and participants were instructed to complete each test as quickly as possible. To elicit maximal effort, players were aware of prizes
Susana Andrade, Angélica Ochoa-Avilés, Wilma Freire, Natalia Romero-Sandoval, Daniel Orellana, Teodoro Contreras, José Luis Pillco, Jessica Sacta, Diana Andrade Muñoz, Patricia Ramírez, Miguel Martin and Silvana Donoso
strength and endurance, agility and flexibility components were evaluated on a nationally representative sample (N = 10257 children 5-17 year). The databases were not accessible, and the available literature do not report physical fitness data stratified by gender. Cardiorespiratory fitness measured by the
). CD and GK were generally taller and heavier (likely small to very likely moderate effects) than other players at each developmental stage and were advanced maturers at U13–U14 (very likely small to likely moderate effects). GK had inferior agility (very likely small to likely moderate effects