Kinematic analysis of the technique for elite male long-distance speed skaters in curving

The purpose of this study was to investigate technical factors for maintaining skating velocity by kinematic analysis of the skating motion for elite long-distance skaters during the curve phase in official championship races. Sixteen world-class elite male skaters who participated in the 5,000-m race were videotaped with two synchronized high-speed video cameras (250 Hz) in a curve lane by using a panning DLT technique. Three-dimensional coordinates of the body and blades during the first and second halves of the races were collected to calculate kinematic parameters. In the group that maintained greater skating velocity, the thigh angle during the gliding phase of the left stroke during the second half was greater than that during the first half, and the center of mass was located more forward during the second half. Thus, it was suggested that long-distance speed skaters should change the support leg position during the gliding phase in the left stroke of the curve phase under fatigued conditions so that they could extend the support leg with a forward rotation of the thigh and less shank backward rotation.     

Supramaximal cycle tests do not detect seasonal progression in performance in groups of elite speed skaters.

Seven female and eight male elite junior skaters performed cycle ergometer tests at four different times during the 1987/1988 season. The tests consisted of a Wingate-type 30-s sprint test and a 2.5-min supramaximal test. The subjects were tested in February, May and September 1987 and in January 1988. Maximal oxygen consumption was measured during the 2.5-min test. With the exception of the maximal oxygen consumption of the women in May which was about 6% lower than in the other three tests, no seasonal changes in the test results could be observed--this, in spite of a distinct increase in training volume (from 10 to more than 20 h.week-1) and training intensity in the course of the season. When the test data were compared to those of elite senior skaters, it appeared that the junior skaters showed the same values for mean power output during the sprint test [14.2 (SD 0.4) W.kg-1 for the men and 12.6 (SD 0.5) W.kg-1 for the women] and maximal oxygen consumption [63.1 (SD 2.8) ml.kg-1.min-1 for the men and 55.3 (SD 3.5) ml.kg-1.min-1 for the women, respectively] as found for senior skaters. It seemed, therefore, that the effects of training in these skaters had already levelled off in the period before they participated in this investigation. In contrast to previous studies, no relationship could be shown between the test results and skating performance. This was most likely due to the homogenous character of the groups (mean standard deviations in power and oxygen consumption were only 5%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Supramaximal test results of male and female speed skaters with particular reference to methodological problems

Six male and six female elite speed skaters were tested during two bicycle ergometer tests: a 30 s sprint test and a 2.5 min supra maximal test. During the 2.5 min test oxygen consumption was measured every 30 s. The males showed 30-31% higher mean power output values both during the sprint test (1103 versus 769 Watt) and during the 2.5 min test (570 versus 390 Watt). Maximal oxygen consumption was 31% higher for the males than for the females (5.10 versus 3.50 1.min-1). However, when expressed per kilogram lean body weight (LBM), power output and oxygen consumption was equal for both sexes. Differences between present and previous results are most likely due to methodological problems with the estimation of load during the supra maximal test. Subjects appear to experience difficulties in distributing their power output over the 2.5 min if they are tested for the first time. For experienced skaters and cyclists, fixed levels of 19 W.kgLBM-1 as initial load setting for the sprint test and 8 W.kg LBM-1 for the 2.5 min test are recommended.     

Effect of cycling exercise on lumbopelvic control performance in elite female cyclists

Objectives:The purpose of the present study is to assess the effects of an intense cycling training session on the stability of the lumbopelvic-hip complex through two dynamic exercise tests - the single-leg-deadlift (SLD) and a variation of the bird-modified dog (BD), via the OCTOcore application.Methods:Thirty-one elite female road cyclists were self-evaluated with their own smartphones, before and immediately after finishing their training sessions. Right, left and composite were measured for each exercise test.Results:There was a significant time effect on performance for both the SLB and BD tests (p<0.05; η²=0.137), and the SLD and BD tests were increased with respect to the pre-test at 15% and 17%, respectively.Conclusion:An intense cycling training session produced significant alterations in lumbopelvic behavior in the elite female cyclists. The OCTOcore application demonstrated that it was a sensitive tool in detecting these changes and it could easily be used by the cyclists themselves.     

Biomotor structures in elite female handball players

In order to identify biomotor structures in elite female handball players, factor structures of morphological characteristics and basic motor abilities of elite female handball players (N = 53) were determined first, followed by determination of relations between the morphological-motor space factors obtained and the set of criterion variables evaluating situation motor abilities in handball. Factor analysis of 14 morphological measures produced three morphological factors, i.e. factor of absolute voluminosity (mesoendomorph), factor of longitudinal skeleton dimensionality, and factor of transverse hand dimensionality. Factor analysis of 15 motor variables yielded five basic motor dimensions, i.e. factor of agility, factor of jumping explosive strength, factor of throwing explosive strength, factor of movement frequency rate, and factor of running explosive strength (sprint). Four significant canonic correlations, i.e. linear combinations, explained the correlation between the set of eight latent variables of the morphological and basic motor space and five variables of situation motoricity. First canonic linear combination is based on the positive effect of the factors of agility/coordination on the ability of fast movement without ball. Second linear combination is based on the effect of jumping explosive strength and transverse hand dimensionality on ball manipulation, throw precision, and speed of movement with ball. Third linear combination is based on the running explosive strength determination by the speed of movement with ball, whereas fourth combination is determined by throwing and jumping explosive strength, and agility on ball pass. The results obtained were consistent with the model of selection in female handball proposed (Srhoj et al., 2006), showing the speed of movement without ball and the ability of ball manipulation to be the predominant specific abilities, as indicated by the first and second linear combination.     

Validity of different EMG analysis methods to identify aerobic and anaerobic thresholds in speed skaters

Purpose: This study aimed to assess the validity of the first (EMGth1) and second (EMGth2) breakpoints in the EMG signal during skating. Scope: Ten well-trained long track speed skaters performed a maximal incremental skating test on a slide board. EMG signals from six lower limb muscles were recorded during the last 15 s of each stage and converted to Root Mean Square for determination EMGth1 and EMGth2 using mathematical (2 and 3 linear regressions) and visual methods. Conclusions: EMGth1 had a low detection rate (<50%) while EMGth2 could be identified visually in > 80% of cases, in 85% of cases using 2-lines and 63% using 3-lines regression. Quads (VL + VM) and Gluts (GM + GMd) had the highest EMGth2 detection rate for all methods (>70%). EMGth2 from Quads and Gluts detected by the 2-lines and 3-lines regression were not different than the second ventilatory threshold (VT2) (p > 0.05), while the visual method overestimated VT2 (p < 0.01). EMGth2 detected from Quads by the 2-lines regression method presented better correlation with VT2 stage (r = 0.91), lowest bias, and limit of agreement. We conclude that EMG is a valid non-invasive method to detect VT2 during skating when using a mathematical method to determine EMGth2.     

Fitness profile of elite Croatian female taekwondo athletes

The aim of the study was to assess fitness profile of elite Croatian female taekwondo athletes and to determine which physical, physiological and motor characteristics differentiate mostly the successful from the less successful fighters. Thirteen national taekwondo champions were divided into two groups according to their senior international competitive achievements. Physiological characteristics, including maximal oxygen uptake (VO2max), were assessed during a continuous progressive treadmill test. The measured motor abilities included explosive and elastic leg strength, maximal strength, muscular endurance, anaerobic alactic power, agility and flexibility. Differences between the successful and less successful athletes were determined using independent t-test. Even though the differences were not statistically significant, the successful athletes had somewhat less fat (2.3%) and were taller by 5.8 cm. The successful athletes achieved significantly higher maximum running speed (15.8 +/- 0.5 versus 14.9 +/- 0. 7 km h(-1); p < 0.05), their ventilatory anaerobic threshold was significantly higher (41.4 +/- 4.1 versus 37.6 +/- 2.0 ml kg(-1) min(-1); p < 0.05) at a significantly lower heart rate (166.8 +/- 6.8 versus 171.0 +/- 8.2 beats min(-1); p < 0.05) than in the less successful athletes. Significant differences were also found in three tests of explosive power (p < 0.05), anaerobic alactic power (p < 0.01), and lateral agility (p < 0.05). The performance of taekwondo female athletes primarily depends on the anaerobic alactic power, explosive power expressed in the stretch-shortening cycle movements, agility and aerobic power.     

Aerobic fitness and performance in elite female futsal players

Despite its growing popularity, few studies have investigated specific physiological demands for elite female futsal. The aim of this study was to determine aerobic fitness in elite female futsal players using laboratory and field testing. Fourteen female futsal players from the Venezuelan National team (age =21.2±4.0 years; body mass =58.6±5.6 kg; height =161±5.0 cm) performed a progressive maximal treadmill test under laboratory conditions. Players also performed a progressive intermittent futsal-specific field test for endurance, the Futsal Intermittent Endurance Test (FIET), until volitional fatigue. Outcome variables were exercise heart rate (HR), VO₂, post-exercise blood lactate concentrations ([La]b) and running speeds (km · h^-1). During the treadmill test, VO₂max, maximal aerobic speed (MAS), HR and peak [La]b were 45.3±5.6 ml · kg^-1 · min^-1, 12.5±1.77 km · h^-1, 197±8 beats · min^-1 and 11.3±1.4 mmol · l^-1, respectively. The FIET total distance, peak running velocity, peak HR and [La]b were 1125.0±121.0 m, 15.2±0.5 km · h^-1, 199±8 beats · min^-1 and 12.5±2.2 mmol · l^-1, respectively. The FIET distance and peak speed were strongly associated (r= 0.85-87, p < 0.0001) with VO₂max and MAS, respectively. Peak HR and [La]b were not significantly different between tests. Elite female futsal players possess moderate aerobic fitness. Furthermore, the FIET can be considered as a valid field test to determine aerobic fitness in elite level female futsal players.     

Biomotor structures in elite female handball players according to performance

In order to identify biomotor structures in elite female handball players, factor structures of morphological characteristics and basic motor abilities, and of variables evaluating situation motor abilities of elite female handball players (n = 53) were determined first, followed by determination of differences and relations of the morphological, motor and specific motor space according to handball performance. Factor analysis of 16 morphological measures produced three morphological factors, i.e. factor of absolute voluminosity, i.e. mesoendomorphy, factor of longitudinal skeleton dimensionality, and factor of transverse hand dimensionality. Factor analysis of 15 motor variables yielded five basic motor dimensions, i.e. factor of agility, factor of throwing explosive strength, factor of running explosive strength (sprint), factor of jumping explosive strength and factor of movement frequency rate. Factor analysis of 5 situation motor variables produced two dimensions: factor of specific agility with explosiveness and factor of specific precision with ball manipulation. Analysis of variance yielded greatest differences relative to handball performance in the factor of specific agility and throwing strength, and the factor of basic motoricity that integrates the ability of coordination (agility) with upper extremity throwing explosiveness and lower extremity sprint (30-m sprint) and jumping (standing triple jump). Considering morphological factors, the factor of voluminosity, i.e. mesoendomorphy, which is defined by muscle mass rather than adipose tissue, was found to contribute significantly to the players'performance. Results of regression analysis indicated the handball performance to be predominantly determined by the general specific motor factor based on specific agility and explosiveness, and by the morphological factor based on body mass and volume, i.e. muscle mass. Concerning basic motor abilities, the factor of movement frequency rate, which is associated with the ability of ball manipulation, was observed to predict significantly the handball players' performance.     

Skeletal muscle properties and performance in elite female track athletes

Selected biochemical and physiological properties of skeletal muscle were studied in light of performance capabilities in 24 elite female track athletes. The feasibility of quantifying end point histochemistry and relating oxidative staining density (reduced nicotinomide adenine dinucleotide diaphorase: NADH-D) to whole body maximal oxygen consumption (VO2 max) was also investigated, while muscle fiber types, classified according to alkaline APTase stains, were studied and related to muscle oxidative capacity (succinate dehydrogenase: SDH), VO2 max and "in vivo" torque-velocity properties. Muscle biopsies were taken from the vastus lateralis of each subject and maximal knee extensor torques were recorded at 30 degrees from full extension at four selected velocities. While results confirm earlier reports on skeletal muscle properties and performance it was concluded that end point histochemistry could be reliably quantified and that an "oxidative" stain such as NADH-D correlates extremely well with VO2 max (r = 0.86, p less than 0.001) whereas correlations between % slow twitch fibres (Alkaline ATPase stain) and VO2 max were lower (r = 0.44, p less than 0.05). Additionally, as knee extension velocity increased from 0-1.7 rad x s-1 angle specific extensor torque production did not decline as observed in vitro and pentathletes displayed significantly larger torques at all velocities when compared to the other athletes. These data confirm that while myofibrillar ATPase staining correlates with force-velocity properties of muscle, VO2 max is better correlated with quantified oxidative staining.     

Contrasts in muscle and myofibers of elite male and female bodybuilders

Muscle cross-sectional area (CSA), fiber area, and fiber number were determined from the biceps brachii of eight elite male bodybuilders (MB) and five elite female bodybuilders (FB) who had similar training characteristics. Biceps CSA was obtained from computer tomographic scanning and corrected for noncontractile tissue. Biceps CSA was twofold greater in MB relative to FB and strongly correlated to lean body mass (R = 0.93). Biceps CSA expressed per kilogram lean body mass (LBM) or per centimeter body height (BH) was 35% greater in MB compared with FB. Most of the gender difference in muscle CSA was because of greater absolute mean fiber areas in MB (9,607 microns2) relative to FB (5,386 microns2); however, MB also had a significantly greater population of small type II fibers (less than 2,000 microns2) compared with FB. Type II fiber area/LBM averaged 1.6-fold greater in MB compared with FB; however, type I fiber area/LBM was similar between groups. Biceps CSA was positively correlated to fiber CSA (R = 0.75) and fiber number (R = 0.55). This suggests that adaptations to resistance training may be complex and involve fiber hypertrophy and fiber number (e.g., proliferation). Alternatively, since the muscle characteristics before training are not known, these apparent adaptations might be genetically determined attributes.     

The control of sexual receptivity in female cockroaches

Female receptivity and sex pheromone production are controlled by different mechanisms. In B. fumigata females the corpora allata control pheromone production. The female's pheromone releases courtship behaviour in the male; he raises his wings exposing his tergum and apparently releases a pheromone. The receptive female is attracted to the male and mounts and ‘feeds’ on his tergum. The mounting and feeding behaviour, which is indicative of female receptivity, is not directly controlled by the corpora allata.

Receptivity in N. cinerea and L. maderae is determined by some event, presumably in the brain, which occurs at about the same time as the onset of activity of the corpora allata. It is suggested that the neurosecretory system is involved in acceptance of the male by the female.     

Match running performance and exercise intensity in elite female Rugby Sevens

The purpose of this study was to describe the match-play demands of professional female rugby players competing in Rugby Sevens (Rugby 7's) matches. Time-motion analyses (global position system) were performed on 12 elite female rugby players during 5 competitive matches in a 2-day international tournament. Data revealed that players covered an average distance of 1,556.2 ± 189.3 m per game (14 minutes). Over this distance, 29.7% (462.6 ± 94.6 m) was spent standing and walking, 33.2% (515.9 ± 88.6 m) jogging, 11.6% (181.0 ± 61.4 m) cruising, 16.4% (255.7 ± 88.3 m) striding, 3.7% (57.1 ± 40.8 m) high-intensity running, and 5.4% (84.0 ± 64.8 m) sprinting. The average maximal distance of sprints, number of sprints, minimum distance of sprint, and mean sprint distance over the game were as follows: 25.8 ± 16.1 m, 5.3 ± 3.2 sprints, 6.5 ± 2.0 m, and 17.2 ± 8.8 m, respectively. The players' work-to-rest ratio was 1:0.4. For over 75% of the game, the players were exposed to heart rates (HRs) >80% of their maximal HR. There were no statistical differences between the first and second halves in any of the variables analyzed. This study suggests that the physical demands of Rugby 7's are quite different from those reported in other rugby codes. For players and teams to remain competitive in female Rugby Sevens, coaching, conditioning, and physical fitness testing should reflect these current demands.     

Aerobic capacities and anthropometric characteristics of elite female soccer players

Ingebrigtsen, J, Dillern, T, and Shalfawi, SAI. Aerobic capacities and anthropometric characteristics of elite female soccer players. J Strength Cond Res 25(12): 3352-3357, 2011-This study investigated aerobic capacities and anthropometric characteristics within a group of 29 elite female soccer players. The purpose was to identify and establish aerobic capacities and anthropometric characteristics for these players and to look for possible positional differences between keepers, defenders, midfielders, and attackers. We did this by measuring standard anthropometrical variables and maximal oxygen (VO(2)max) and anaerobic threshold (AT). One-way analysis of variance revealed no significant differences among anthropometric or physiological variables. However, a trend (p = 0.062) toward positional differences was found within running speed at AT. A subsequent Tukey post hoc test showed differences (p = 0.04) between keepers and defenders, with the latter running faster (～1.7 km·h) at AT. The present results suggest that few anthropometric and physiological differences exist between playing positions in elite female soccer players. Furthermore, the current results indicate that present elite players' physiological characteristics are similar to those previously shown, despite the rapid changes of the female soccer game. Based on well-established knowledge that different playing positions within a soccer team ought to have distinct capacities, we recommend regular testing programs to be able to construct and implement tailored training programs for players' physical capacities with respect to the demands of their playing positions.     

Gender-related differences in elite gymnasts: the female athlete triad.

High-intensity training can alter the normal pattern of pubertal development in elite gymnasts. We investigated sex hormones, the ob gene product leptin, body composition, nutrition, and eating habits in female and male elite gymnasts from national cadres to elucidate gender-related differences. Serum leptin levels were decreased, particularly in pubertal girls, and did not show the normal developmental pattern. After leptin levels were transformed into standard deviation scores, mainly pubertal female gymnasts had significantly lower values than normal controls of the same gender, pubertal stage, and body mass index. The percentage of body fat was reduced compared with a normal age-matched population in both genders but to a higher degree in female gymnasts. When leptin standard deviation scores were based on percent body fat instead of body mass index, mean values were still significantly decreased compared with those of normal controls: -1.05 in girls (P < 0.001) and -0.60 in boys (P = 0.025). In both genders, total energy consumption and nutritional intake were insufficient, although to a lesser extent in male gymnasts. Pubertal development is influenced to a different degree in female and male elite gymnasts. In contrast to their male counterparts, high-intensity training takes place during the sensitive phase of pubertal maturation in female gymnasts. Whereas the girls displayed low estrogen levels, hypoleptinemia, reduced body fat mass, insufficient caloric intake, and retarded menarche, the pubertal development of male gymnasts remained almost unaltered.     

Short-term effects of lumbopelvic complex stability training in elite female road cyclists

Objectives:The purpose of this study was to determine the effects of short-term lumbopelvic stability training on muscular endurance and stability in elite female cyclists.Methods:Twenty-four female road cyclists were randomly allocated to a core training group (CTG, n=12) or control group (CG, n=12). In addition to their scheduled training the CTG performed a core training program, that consisted of 6 core exercises performed in a session every other day until a total of 8 training sessions were completed. The CG did not receive the core training program and completed their scheduled training. The lumbopelvic-hip complex was assessed pre- and post-core program included the following exercises: single leg deadlift (SLD), bird-dog (BD), plank test (PT), and side-bridge plank test (SPT).Results:In comparison to CG, CTG significantly improved the time to failure in PT, SPT-Left, and SPT-Right (p<0.05). Further, CTG resulted in a significant decrease in SLD (p<0.05) compared to CG for the three accelerometry measures.Conclusion:The present results indicate that following 8 sessions of lumbopelvic stability training muscular endurance and core stability were enhanced.     

The ratio and allometric scaling of speed, power, and strength in elite male rugby union players

This study compared the effectiveness of ratio and allometric scaling for normalizing speed, power, and strength in elite male rugby union players. Thirty rugby players (body mass [BM] 107.1 ± 10.1 kg, body height [BH] 187.8 ± 7.1 cm) were assessed for sprinting speed, peak power during countermovement jumps and squat jumps, and horizontal jumping distance. One-repetition maximum strength was assessed during a bench press, chin-up, and back squat. Performance was normalized using ratio and allometric scaling (Y/X), where Y is the performance, X, the body size variable (i.e., BM or BH), and b is the power exponent. An exponent of 1.0 was used during ratio scaling. Allometric scaling was applied using proposed exponents and derived exponents for each data set. The BM and BH variables were significantly related, or close to, performance during the speed, power and/or strength tests (p < 0.001-0.066). Ratio scaling and allometric scaling using proposed exponents were effective in normalizing performance (i.e., no significant correlations) for some of these tests. Allometric scaling with derived exponents normalized performance across all the tests undertaken, thereby removing the confounding effects of BM and BH. In terms of practical applications, allometric scaling with derived exponents may be used to normalize performance between larger rugby forwards and smaller rugby backs, and could provide additional information on rugby players of similar body size. Ratio scaling may provide the best predictive measure of performance (i.e., strongest correlations).