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VO2max, ventilatory and anaerobic thresholds in rhythmic gymnasts and young female dancers
No full textBackground. This study examines the fitness level of a rhythmic gymnasts group and a young female classical dancers group. Methods. Aerobic power (V̇O2max), individual ventilatory (IVT) and anaerobic thresholds (IAT) were assessed in 12 elite rhythmic gymnasts, eight elite ballet dancers and 12 sedentary female subjects in the same age range (13-16 yrs). The V̇O2max, IVT and TAT were assessed during a continuous incremental running treadmill test. Results. At IVT and IAT the V̇O2max expressed in ml·kg-1·min-1 was significantly different between the three groups of subjects. The highest values were found in gymnasts (30.8±2.6 for IVT and 43.8±3.5 for IAT) followed by the values of dancers (21.7±2.8 for IVT and 30.5±3.1 for IAT) and controls (15.6±2.0 for IVT and 20.6±1.7 for IAT). When the V̇O2max was expressed in percent of V̇O2max, the values at IAT were significantly different between all groups (gymnasts: 84.9±0.7; dancers: 64.0±4.1; controls: 59.7±2.4) while at IVT no difference was found between dancers and controls (45.6±4.1 and 45.2±16, respectively). At maximal effort V̇O2 was significantly higher both in gymnasts and dancers (51.7±4.4 and 47.5±3.0 ml·kg-1·min-1, respectively), than in controls (34.5±2.5 ml·kg-1·min-1). Conclusions. Although V̇O2max was similar between gymnasts and dancers, V̇O2 values at NT and IAT were able to discriminate the higher level of fitness in gymnasts with respect to dancers
A simple method for individual anaerobic threshold as predictor of max lactate steady state
No full textBackground: The individual anaerobic threshold (IAT) is defined (18) as the highest metabolic rate where blood lactate (La) concentrations are maintained at a steady-state during prolonged exercise. Stegmann et al.'s (18) method to detect IAT, using La-performance relationship during incremental graded exercise, is based on the assumption that La is in relatively steady state by the end of each 3-min stage of work rate. However, at the end of a 3-min stage, an La steady state (Lass) is not reached (13). Purpose: The present study was designed to investigate whether the IAT should be determined by attributing La value to the antecedent stage (IAT(a)) or to the same stage of its measurement (IAT(m)), then to verify whether this IAT would be a valid indicator of the max Lass during prolonged exercise. Methods: Forty-one athletes (21 male and 20 female), regularly involved in different physical training, performed three exercise tests on treadmill. The first one was a 3-min stage incremental test to detect the IAT(a) and IAT(m). The other two tests were 30-min prolonged tests at the IAT(a) and IAT(m) workload. Lass were present in IAT(a) intensity (about 4.0 mmol · L-1) both in male and female athletes, whereas at IAT(m) intensity a Lass was not present and a premature break-off occurred in some cases. Discussion: This protocol can be useful for practical use because: 1) the method of choosing the anaerobic threshold is easy to apply; 2) it does not require to reach the maximal effort; and 3) although in some cases the IAT(a) could probably underestimate the workload of max Lass, the IAT(a) can be regarded as guideline to define the intensity of endurance training
Factors influencing performance of competitive and amateur rhythmic gymnastics- Gender differences
No full textDuring last decade, male athletes were involved in official rhythmic gymnastics (RG) competitions. Aim of this study was to examine anthropometric characteristics and motor skills of male rhythmic gymnasts to identify guidelines in talent identification, selection and development training plans. Twenty-four gymnasts (age range 22+/-4 years), 12 male athletes and 12 female athletes, underwent two testing sessions: the previous session to assess anthropometric measures, and the second one to evaluate jumping ability using Optojump. Three vertical jumps: squat jump (SJ), counter-movement jump (CMJ), hopping test (HT) and three different technical jumps (Split Leap with stretched legs (SL); Cossack with 180 degrees of rotation (CK); Jeté with turn (JWT)) were evaluated. Male gymnasts had significant higher values in each anthropometric measure than females (p<0.01) except for sitting height/stature ratio, sitting height and fat mass (no significant differences). Female athletes were selected for their lowest fat mass. Height and ground contact time of technical leaps, squat jump and counter-movement jump, were significantly higher in male athletes than females. Height of hopping test (evaluating stiffness), and of difference between CMJ and squat jump (evaluating elastic properties of muscles) were no different between genders. Ground contact time of hopping test was significantly correlated (p<0.05) with ground contact time of technical leaps. Results of the present study suggest that similar anthropometric characteristics have to be researched for both gymnasts' gender. Reactivity and elastic muscle properties of the legs have to be research both in male and female athletes
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Is explosive performance influenced by androgen concentrations in young male soccer players?
No full textOBJECTIVE:
There is growing interest in the implementation and assessment of strength and conditioning programmes among young children. The purpose of this study was to examine the association between given anthropometric characteristics, pubertal development, salivary androgen hormones and explosive leg power in young soccer players.
METHODS:
51 (age range 10-14 years) soccer players were investigated. The relations between age, pubertal developmental stages, testicular volume, weight, height, body fat, fat free mass, salivary DHEAS concentrations, salivary testosterone concentrations and lower limb explosive power were evaluated.
RESULTS:
Standing long jump length was positively correlated (p<0.05) with age (11.7 (SD 1.2) years, r = 0.66), pubertal developmental stages (mode and range: 1 (1-4), r = 0.64), testicular volume (8.8 (5.2) ml, r = 0.58), height (1.50 (0.10) m, r = 0.34), weight (43.7 (9.1) kg, r = 0.34), fat free mass (35.4 (7.2) kg, r = 0.67), salivary DHEAS concentrations (4.4 (1.2) ng/ml, r = 0.38) and negatively correlated with body fat (18.6 (7.0) kg; r = -0.49, p<0.05). There was no significant correlation between salivary testosterone concentrations (0.3 (0.1) ng/ml, r = 0.12) and standing long jump.
CONCLUSIONS:
Results of the present investigation demonstrated that age, pubertal developmental stages, testicular volume, weight, height, fat free mass, and salivary DHEAS concentrations were associated with standing long jump performance. In addition, salivary testosterone concentrations were not related to explosive leg power. Results of the present investigation suggest that the teacher/coach should evaluate long jump performance relative to the subject's given biological characteristics, and not simply established standards based on chronological age
Do non-steroidal anti-inflammatory drugs influence the steroid hormone milieu in male athletes?
No full textProstaglandins modulate the hypothalamus-pituitary-adrenal and -gonadal axis pathways. We explored the effects of a single course of treatment with acetylsalicylic acid (ASA), an inhibitor of prostaglandin synthesis, on the steroid milieu in athletes. Morning plasma cortisol (F), dehydroepiandrosterone sulphate, free-testosterone, testosterone (T) and their ratios were evaluated before and after the administration of either ASA or placebo in twelve male athletes, when affected by minor musculoskeletal trauma and, as control, after a five/six week wash-out in healthy conditions respectively. One tablet of ASA (800 mg), or placebo, was administered two times daily for 10 days during treatment. All the volunteers suspended exercise training during treatment. The results revealed that compared to placebo, plasma F was significantly lower after ASA treatment (p = 0.023). Furthermore, the comparison of hormone's absolute and percentage of variations (A and A%) between ASA and placebo treatment showed significant differences respectively for AF (p = 0.045), for AT (p = 0.047), for AT/F (p = 0.042), for AF% (p = 0.04) and for AT% (p = 0.049). Our data suggest that in comparison to placebo, a short-term ASA treatment is able to influence the plasma steroid milieu in athletes. Due to the observed variability of the individual hormonal patterns, further research is required to substantiate these findings
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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