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1.
Abstract

This study determined the precision of pencil and fan beam dual-energy X-ray absorptiometry (DXA) devices for assessing body composition in professional Australian Football players. Thirty-six professional Australian Football players, in two groups (fan DXA, N = 22; pencil DXA, N = 25), underwent two consecutive DXA scans. A whole body phantom with known values for fat mass, bone mineral content and fat-free soft tissue mass was also used to validate each DXA device. Additionally, the criterion phantom was scanned 20 times by each DXA to assess reliability. Test–retest reliability of DXA anthropometric measures were derived from repeated fan and pencil DXA scans. Fat-free soft tissue mass and bone mineral content from both DXA units showed strong correlations with, and trivial differences to, the criterion phantom values. Fat mass from both DXA showed moderate correlations with criterion measures (pencil: r = 0.64; fan: r = 0.67) and moderate differences with the criterion value. The limits of agreement were similar for both fan beam DXA and pencil beam DXA (fan: fat-free soft tissue mass = ?1650 ± 179 g, fat mass = ?357 ± 316 g, bone mineral content = 289 ± 122 g; pencil: fat-free soft tissue mass = ?1701 ± 257 g, fat mass = ?359 ± 326 g, bone mineral content = 177 ± 117 g). DXA also showed excellent precision for bone mineral content (coefficient of variation (%CV) fan = 0.6%; pencil = 1.5%) and fat-free soft tissue mass (%CV fan = 0.3%; pencil = 0.5%) and acceptable reliability for fat measures (%CV fan: fat mass = 2.5%, percent body fat = 2.5%; pencil: fat mass = 5.9%, percent body fat = 5.7%). Both DXA provide precise measures of fat-free soft tissue mass and bone mineral content in lean Australian Football players. DXA-derived fat-free soft tissue mass and bone mineral content are suitable for assessing body composition in lean team sport athletes.  相似文献   

2.
Abstract

The aims of this study were to describe the current anthropometric profiles of elite Australian female and male cricket fast bowlers and establish a set of reference values useful for future investigations on player selection, talent identification, and training programme development. The participants were 26 female (mean age 22.5 years, s = 4.5; height 1.71 m, s = 0.05; body mass 66.2 kg, s = 7.5) and 26 male (mean age 23.9 years, s = 3.5; height 1.88 m, s = 0.05; body mass 87.9 kg, s = 8.2) fast bowlers. The anthropometric profiles included the measurement of skinfolds, and segment lengths, breadths, and girths. A series of derived variables assessing the distribution of subcutaneous adipose tissue, the bivariate overlap zone, relative body size and proportionality, and somatotype were also calculated. The male bowlers had larger length, breadth, and girth measurements than their female counterparts. There were differences in proportionality between the sexes, with only the male bowlers exhibiting characteristics that could be considered “large” relative to height. The female bowlers had a higher sum of seven skinfolds (P < 0.001), were more endomorphic (F 1,50 = 30.18, P < 0.001), and less mesomorphic (F 1,50 = 10.85, P < 0.01) than the male bowlers. These reference data should be useful to practitioners and researchers interested in cricket. Further research is needed to clarify why only male fast bowlers had variables that were proportionally large relative to height.  相似文献   

3.
Abstract

Anthropometry and body composition were investigated in 43 female handball players from the Italian championships, grouped according to their competitive level (elite vs. sub-elite) or their playing position [goalkeeper (n = 7), back (n = 14), wing (n = 18), or pivot (n = 4)]. The anthropometry consisted of several circumferences, lengths, widths, and skinfold measurement at six sites; the regional and total body compositions were assessed by means of dual-energy X-ray absorptiometry (DXA). One-way ANOVA was used for statistical analysis, with a Bonferroni post-hoc test where needed. The results showed that elite players have significantly lower percentages of fat and higher bone mineral content than sub-elite as well as a clear tendency to accrue more lean mass, especially in upper limbs. Overall, the physical characteristics and body composition of handball players in Italy compared unfavourably with those in other countries, suggesting a need for improved selection and training. When playing position was included in the analysis of the whole group of handball players (n = 43) significant differences were found between the stature, mass, body mass index (BMI), several skinfolds, circumferences and lengths, and total body mineral mass, lean mass and fat mass of players in different positions. Post-hoc analysis suggests that players on the wing and in goalkeeper positions differed most from one another. These findings confirm and expand on previous data about the presence of anthropometric differences within playing positions in handball.  相似文献   

4.
Abstract

We compared the movement patterns of cricketers in different playing positions across three formats of cricket (Twenty20, One Day, multi-day matches). Cricket Australia Centre of Excellence cricketers (n = 42) from five positions (batting, fast bowling, spin bowling, wicketkeeping, and fielding) had their movement patterns (walk, jog, run, stride, and sprint) quantified by global positioning system (GPS) technology over two seasons. Marked differences in movement patterns were evident between positions and game formats, with fast bowlers undertaking the greatest workload of any position in cricket. Fast bowlers sprinted twice as often, covered over three times the distance sprinting, with much smaller work-to-recovery ratios than other positions. Fast bowlers during multi-day matches covered 22.6 ± 4.0 km (mean ± s) total distance in a day (1.4 ± 0.9 km in sprinting). In comparison, wicketkeepers rarely sprinted, despite still covering a daily total distance of 16.6 ± 2.1 km. Overall, One Day and Twenty20 cricket required ～50 to 100% more sprinting per hour than multi-day matches. However, multi-day cricket's longer duration resulted in 16–130% more sprinting per day. In summary, the shorter formats (Twenty20 and One Day) are more intensive per unit of time, but multi-day cricket has a greater overall physical load.  相似文献   

5.
Fast bowling in cricket is an activity that is well recognised as having high injury prevalence and there has been debate regarding the most effective fast bowling technique. The aim of this study was to determine whether two-year coaching interventions conducted in a group of elite young fast bowlers resulted in fast bowling technique alteration. Selected kinematics of the bowling action of 14 elite young fast bowlers were measured using an 18 camera Vicon Motion Analysis system before and after two-year coaching interventions that addressed specific elements of fast bowling technique. Mann-Whitney tests were used to determine whether any changes in kinematic variables occurred pre- and post-intervention between those who had the coaching interventions and those who didn't. The coaching interventions, when applied, resulted in a more side-on shoulder alignment at back foot contact (BFC) (p = 0.002) and decreased shoulder counter-rotation (p = 0.001) however, there was no difference in the degree of change in back and front knee flexion angles or lower trunk side-flexion. This study has clearly shown that specific aspects of fast bowling technique are changeable over a two-year period in elite level fast bowlers and this may be attributed to coaching intervention.  相似文献   

6.
The aim of this cross-sectional study was to compare bone mass in young female athletes playing ball games on different types of playing surfaces. About 120 girls, 9–13 years of age (10.6 ± 1.5 years old Tanner I–III) were recruited and divided into prepubertal and pubertal groups. The sample represented 3 groups of athletes: soccer (N = 40), basketball (N = 40), and handball (N = 40); and 6 different playing surfaces (soccer – ground, soccer – artificial turf, basketball – synthetic, basketball – parquet, handball – synthetic, and handball – smooth concrete). Total and regional body composition (bone mass, fat mass, and lean mass) were measured by dual-energy X-ray absorptiometry (DXA). The mechanical properties of the surfaces (force reduction, vertical deformation, and energy return) were measured with the Advanced Artificial Athlete (Triple A) method. The degree of sexual development was determined using Tanner test. The pubertal group showed that soccer players on the ground, basketball players on synthetic, and handball players on smooth concrete had higher values of bone mineral content (BMC) and bone mineral density (BMD) (P < 0.05) than the soccer players on the artificial turf, basketball players on parquet, and handball players on synthetic. In conclusion, a hard playing surface, with less vertical deformation and force reduction, and greater energy return, is associated with higher levels of BMD and BMC in growing girls, regardless of the sport they practice.  相似文献   

7.
This study investigated the change in body composition and bone mineral content (BMC) of senior rugby league (RL) players between 2008 and 2014. Twelve male professional RL players (age, 24.6 ± 4.0 years; stature, 183.4 ± 8.4 cm) received a dual-energy X-ray absorptiometry scan during preseason in 2008 and 2014. Between 2008 and 2014, very likely increases in leg lean mass (LM), total trunk and leg BMC, and a likely increase in arm BMC and possible increases in body mass (BM), total and trunk fat mass (FM), and total, trunk and arm LM were observed. Unlikely decreases and unclear changes in leg and arm FM were also found. Large negative correlations were observed between age and BM (r = ?0.72), LM (r = ?0.70), FM (r = ?0.61) and BMC (r = ?0.84) change. Three participants (19.1 ± 1.6 years) increased LM by 7.0–9.3 kg. Younger players had the largest increases in LM during this period, although an older player (30-year old) still increased LM. Differences in body composition change were also observed for participants of the same age, thus contextual factors should be considered. This study demonstrates the individuality of body composition changes in senior professional rugby players, while considering the potential change in young athletes.  相似文献   

8.
This study aimed to investigate the effect of contact (C-SSG) and no-contact (NC-SSG) handball small-sided games (SSGs) on motion patterns and physiological responses of elite handball players. Twelve male handball players performed 10 C-SSG and 10 NC-SSG while being monitored through the heart rate (HR) and rate of perceived exertion (RPE) as physiological responses and time-motion activities profile using video-match analysis. Both game conditions resulted in similar HR responses (P > 0.05), but the NC-SSG led to a higher RPE scores. The time-motion activity analysis featured NC-SSG with a greater amount of walking (855.6 ± 25.1 vs. 690.6 ± 35.2 m) and backward movements (187.5 ± 12.3 vs. 142.5 ± 8.7 m) combined with fast running (232.3 ± 8.5 vs. 159.7 ± 5.7 m) and sprinting (79.5 ± 4.7 vs. 39.7 ± 3.7 m) activities (P < 0.001). Conversely, C-SSG had a higher percentage of jogging and sideway movements associated with greater frequency of jumping (0.87 ± 0.09 vs. 0.31 ± 0.06 nr) and physical contact (1.82 ± 0.55 vs. 0.25 ± 0.03 nr) events (P < 0.001). No between-regimen differences were found for the number of throws (P = 0.745). In addition, the RPE was significantly correlated with fast running relative distances (r = 0.909, P < 0.001) and sprinting relative distances (r = 0.939, P < 0.001). In conclusion, this investigation showed that both C-SSG and NC-SSG in team handball can effectively represent specifically oriented exercises, according to the sport-task and the performance demands.  相似文献   

9.
This study describes the body composition traits of modern-day elite rugby union athletes according to playing position and ethnicity. Thirty-seven international Australian rugby athletes of Caucasian and Polynesian descent undertook body composition assessment using dual-energy X-ray absorptiometry and surface anthropometry. Forwards were significantly taller, heavier and had a greater total fat mass and lean mass than backs. Backs displayed a higher percentage lean mass and lower sum of seven skinfolds and percentage fat mass. While no whole body composition differences were seen between ethnicities, significant regional differences were observed. In the periphery (arm and leg) regions, Polynesians had a greater proportion of fat mass (53.1% vs. 51.3%, P = 0.052, d = 0.5) and lean mass (49.7% vs. 48.6%, P = 0.040, d = 0.9), while in the trunk region a lower proportion of fat mass (37.2% vs. 39.5%, P = 0.019, d = 0.7) and lean mass (45.6% vs. 46.8%, P = 0.020, d = 1.1). Significant differences were also seen between Caucasian and Polynesian forwards in leg lean mass (31.4 kg vs. 35.9 kg, P = 0.014, d = 2.4) and periphery lean mass (43.8 kg vs. 49.6 kg, P = 0.022, d = 2.4). Elite Polynesian rugby athletes have different distribution patterns of fat mass and lean mass compared to Caucasians, which may influence their suitability for particular positions.  相似文献   

10.
Gaelic Football and Hurling are two sporting codes within the Gaelic Athletic Association. The purpose of this study was to report the body composition phenotype of inter-county Gaelic athletic association players, comparing groups by code and field position. 190 senior, male, outfield inter-county players (144 hurlers and 46 Gaelic footballers) were recruited. Stature and body mass was measured, estimates of three components of body composition, i.e. lean mass, fat mass and bone mineral content was obtained by dual energy X-ray absorptiometry (DXA), and normative data for Gaelic athletic association athletes by code and position was compared. Other than in the midfield, there was limited difference in body composition between codes or playing position. Stature-corrected indices nullified any existing group differences between midfielders for both codes. Further comparisons with a non-athletic control group (n = 431) showed no difference for body mass index (BMI); however, the athletic group has a lower fat mass index, with a greater lean mass in accounting for the matched BMI between groups. In addition to providing previously unknown normative data for the Gaelic athletic association athlete, a proportional and independent tissue evaluation of body composition is given.  相似文献   

11.
Abstract

Body composition is a key consideration in the physical make-up of professional soccer players. The aims of the present study were to determine whether the body composition of professional soccer players varied according to playing position, international status or ethnicity, and to establish which variables best distinguished the soccer players from a reference group. Body composition was assessed using dual-energy X-ray absorptiometry in 64 male professional soccer players. Measured variables included bone mineral density and the relative amounts of lean and fat mass. Data were analysed using analysis of variance and stepwise discriminant function. The soccer players recorded better values than a reference group (n = 24) for all body composition compartments. Percent lean mass and bone mineral density were the variables best able to identify the soccer players (95.5% correctly classified). Differences in body composition were evident between goalkeepers and outfield players, but not between outfield playing positions. No differences were found on the basis of international status. The non-Caucasian players demonstrated significantly lower percent body fat (9.2 ± 2.0%) than the Caucasian players (10.7 ± 1.8%). It was concluded that body composition is important for elite soccer players, but that homogeneity between players at top professional clubs results in little variation between individuals.  相似文献   

12.
The purpose of this study was to assess the reproducibility of body composition measurements by dual-energy X-ray absorptiometry (DXA) in 12 elite male wheelchair basketball players (age 31 ± 7 years, BMI 21 ± 2 kg/m2 and onset of disability 25 ± 9 years). Two whole body scans were performed on each participant in the supine position on the same day, using Lunar Prodigy Advance DXA (GE Lunar, Madison, WI, USA). Participants dismounted from the scanning table and were repositioned in-between the first and second scan. Whole body coefficient of variation (CV) values for bone mineral content (BMC), fat mass (FM) and soft tissue lean mass (LTM) were all <2.0%. With the exclusion of arm FM (CV = 7.8%), CV values ranged from 0.1 to 3.7% for all total body and segmental measurements of BMC, FM and LTM. The least significant change that can be attributed to the effect of treatment intervention in an individual is 1.0 kg, 1.1 kg, 0.12 kg for FM, LTM, and BMC, respectively. This information can be used to determine meaningful changes in body composition when assessed using the same methods longitudinally. Whilst there may be challenges in the correct positioning of an individual with disability that can introduce greater measurement error, DXA is a highly reproducible technique in the estimation of total and regional body composition of elite wheelchair basketball athletes.  相似文献   

13.
The aim of this study was to investigate the effectiveness of a caffeine-containing energy drink to enhance physical and match performance in elite badminton players. Sixteen male and elite badminton players (25.4 ± 7.3 year; 71.8 ± 7.9 kg) participated in a double-blind, placebo-controlled and randomised experiment. On two different sessions, badminton players ingested 3 mg of caffeine per kg of body mass in the form of an energy drink or the same drink without caffeine (placebo). After 60 min, participants performed the following tests: handgrip maximal force production, smash jump without and with shuttlecock, squat jump, countermovement jump and the agility T-test. Later, a 45-min simulated badminton match was played. Players’ number of impacts and heart rate was measured during the match. The ingestion of the caffeinated energy drink increased squat jump height (34.5 ± 4.7 vs. 36.4 ± 4.3 cm; P < 0.05), squat jump peak power (P < 0.05), countermovement jump height (37.7 ± 4.5 vs. 39.5 ± 5.1 cm; P < 0.05) and countermovement jump peak power (P < 0.05). In addition, an increased number of total impacts was found during the badminton match (7395 ± 1594 vs. 7707 ± 2033 impacts; P < 0.05). In conclusion, the results show that the use of caffeine-containing energy drink may be an effective nutritional aid to increase jump performance and activity patterns during game in elite badminton players.  相似文献   

14.
Abstract

Triathlon is a popular outdoor endurance sport performed under a variety of environmental conditions. The aim of this study was to assess physiological variables before and after a half-ironman triathlon in the heat and to analyse their relationship with performance. Thirty-four well-trained triathletes completed a half-ironman triathlon in a mean dry temperature of 29 ± 3ºC. Before and within 1 min after the end of the race, body mass, core temperature, maximal jump height and venous blood samples were obtained. Mean race time was 315 ± 40 min, with swimming (11 ± 1%), cycling (49 ± 2%) and running (40 ± 3%) representing different amounts of the total race time. At the end of the competition, body mass changed by ?3.8 ± 1.6% and the change in body mass correlated positively with race time (r = 0.64; P < 0.001). Core temperature increased from 37.5 ± 0.6ºC to 38.8 ± 0.7ºC (P < 0.001) and post-race core temperature correlated negatively with race time (r = ?0.47; P = 0.007). Race time correlated positively with the decrease in jump height (r = 0.38; P = 0.043), post-race serum creatine kinase (r = 0.55; P = 0.001) and myoglobin concentrations (r = 0.39; P = 0.022). In a half-ironman triathlon in the heat, greater reductions in body mass and higher post-competition core temperatures were present in faster triathletes. In contrast, slower triathletes presented higher levels of muscle damage and decreased muscle performance.  相似文献   

15.
We aimed to assess the agreement of a commercially available bioelectrical impedance analysis (BIA) device in measuring changes in fat, lean and bone mass over a 10-week lifestyle intervention, with dual energy X-ray absorptiometry (DXA) as reference. A sample of 136 volunteers (18–66 years) underwent a physical activity intervention to enhance lean mass and reduce fat mass. BIA (Tanita BC545) and DXA (Hologic Explorer) measures of whole-body composition were taken at baseline and at the end of the intervention. After an average of 74 ± 18 days intervention, DXA showed significant changes in 2 of 3 outcome variables: reduced fat mass of 0.802 ± 1.092 kg (P < 0.001), increased lean mass of 0.477 ± 0.966 kg (P < 0.001); minor non-significant increase of 0.007 ± 0.041 kg of bone mass (P = 0.052). The respective changes in BIA measures were a significant reduction of 0.486 ± 1.539 kg fat (P < 0.001), but non-significant increases of 0.084 ± 1.201 kg lean mass (P = 0.425), and 0.014 ± 0.091 kg bone (P = 0.074). Significant, but moderately weak, correlations were seen in absolute mass changes between DXA and BIA: 0.511 (fat), 0.362 (lean) and 0.172 (bone). Compared to DXA, BIA demonstrated mediocre agreement to changes in fat mass, but poor agreement to lean mass changes. BIA significantly underestimated the magnitude of changes in fat and lean mass compared to DXA.  相似文献   

16.
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17.
Abstract

The aim of this study was to compare bone density and body composition measurements in women participating in elite-level netball and golf, two sports with contrasting loading characteristics. Bone mineral density (BMD) and body composition were measured using dual-energy X-ray absorptiometry (DXA) in 14 state-level netball players (20.8±3.4 years), 11 single-digit handicap golf players (22.4±2.1 years) and a control group (n=18) not training for sport (22.6±3.6 years). Trunk extensor endurance and grip strength were also measured using the Sorensen test and hand-grip dynamometry respectively. Netball players had significantly higher total body, lumbar spine and hip BMD than the golf players (P<0.001) and control subjects (P<0.001). The golf players had higher BMD than the control subjects only in the lumbar spine (P<0.05). The netball players were significantly taller than the golf players and control group (P<0.01) and had a higher body mass than the control group (P<0.001). After adjustment for body height and mass, the BMD values in the netball players remained significantly higher than the control subjects at all sites (P<0.01), while the golf players had significantly higher lumbar spine BMD than the controls (P<0.05). Elite-level netball participation is associated with increased total body, hip and lumbar spine BMD, while this response was only evident in the lumbar spine in elite golf players. The contrasting loading characteristics of these sports may be reflected in the site-specific differences in BMD when compared to non-athletic control subjects.  相似文献   

18.
Stand-up paddle boarding (SUP) is a rapidly growing activity where only anecdotal evidence exists for its proposed health and fitness benefits. The purpose of this study was to profile elite and recreational SUP with respect to anthropometric, physiological and musculoskeletal measurements. A total of 30 SUP participants (15 recreational, 15 elite) and 15 sedentary controls participated in this study. Elite and recreational (rec) SUP participants had significantly lower body fat than sedentary (sed) individuals, elite had significantly higher HDL and significantly lower triglycerides than other groups during lipid profiling (P > 0.05). There were significant differences (P > 0.05) between all groups in maximal oxygen uptake (elite 43.7, s = 5.89 ml · kg–1 · min–1 vs. rec 31.9, s = 7.7 ml · kg–1 · min–1 vs. sed 20.4, s = 3.7 ml · kg–1 · min–1) and anaerobic power outputs (35.7, s = 11.1 W vs. 25.0, s = 11.7 W vs. 13.5, s = 7.1 W). The elite group displayed significantly longer endurance than the recreational and sedentary group in the prone bridge (elite 253.4, s = 67.6 s vs. rec 165.6, s = 42.2 s vs. sed 69.7, s = 31.2 s), right-sided bridge (elite 107.9, s = 34.0 s vs. recreational 68.2, s = 24.1 s vs. sed 34.6, s = 15.5 s), left-sided bridge (elite 99.8, s = 24.9 s vs. rec 68.2, s = 27.2 s vs. sed 32.5, s = 15.2 s) and Biering Sorensen test (elite 148.8, s = 35.4 s vs. rec 127.2, s = 43.2 s vs. sed 71.1, s = 32.9 s). Elite SUP had significantly better static and dynamic postural control when compared to the other groups. This study demonstrates the anthropometric, physiological and musculoskeletal values representative of elite and recreational SUP. SUP appears to be associated with increased levels of aerobic and anaerobic fitness, increased static and dynamic balance and a high level of isometric trunk endurance.  相似文献   

19.
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20.
Abstract

The aims of this study were to determine the validity of fat mass of the trunk as a predictor for visceral fat area at the umbilicus level and to develop equations to predict visceral fat mass at the umbilicus level using fat mass of the trunk measured by dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). The participants were 121 normal Japanese adults (69 males, 52 females). Another 60 volunteer adults (34 males, 26 females) were recruited for examination of cross-validity. Altogether, 41 adults (15 males, 26 females) in the original group and 19 adults (7 males, 12 females) in the cross-validity group received BIA measurement. We measured fat mass by DXA and the BIA system, which was a single-frequency BIA with 8-point contact electrodes, and visceral fat area by computed tomography. We observed significant correlations for visceral fat area in waist circumference (0.56) and fat mass of the trunk measured by DXA (0.64). There was no significant difference in fat mass of the trunk between the DXA and BIA systems, but the BIA system tended to provide an underestimate compared with DXA. With combined fat mass of the trunk measured by DXA and waist circumference as predictors, visceral fat area was estimated by equation (1) (R = 0.87, R 2 = 0.76, standard error of the estimate = 20.9 cm2). When substituting fat mass of the trunk measured by BIA into equation (1), there was no significant difference in visceral fat area between the reference and predicted values. An equation using fat mass of the trunk measured by BIA (equation 2) was obtained (R = 0.89, R 2 = 0.78, standard error of the estimate = 20.7 cm2), but a systematic error was found for the males. There was cross-validity in both equations. In conclusion, fat mass of the trunk is an effective predictor for the visceral fat area at the umbilicus level. Fat mass of the trunk measured by BIA might be a valid method to predict visceral fat, although further studies with larger samples taking into account the extent and type of obesity are required.  相似文献   

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