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1.
ABSTRACT

This study investigated changes in body composition in relation to training load determined using RPE and duration (sRPE), and its relationship with physical qualities over a preseason period. Sixteen professional academy players (age = 17.2 ± 0.7 years; stature = 179.9 ± 4.9 cm; body mass = 88.5 ± 10.1 kg) participated in the study. Body composition was assessed before and after each training phase and physical qualities assessed at the start and end of preseason. Across the whole preseason period, skinfold thickness, body fat percentage and fat mass were most likely lower (ES = ?0.73 to ?1.00), and fat free mass and lean mass were likely to most likely higher (ES = 0.31 to 0.40). Results indicated that the magnitude of change appeared phase-dependent (ES = ?0.05 to ?0.85) and demonstrated large individual variability. Changes in physical qualities ranged from unclear to most likely (ES = ?0.50 to 0.64). Small to moderate correlations were observed between changes in body composition, and TL with changes in physical qualities. This study suggests training phase and TL can influence a player’s body composition; that large inter-participant variability exists; and that body composition and TL are related to the change in physical qualities.  相似文献   

2.
Although it is clear that rowers have a large muscle mass, their distribution of muscle mass and which of the main motions in rowing mediates muscle hypertrophy in each body part are unclear. We examine the relationships between partial motion power in rowing and muscle cross-sectional area of the thigh, lower back, and upper arms. Sixty young rowers (39 males and 21 females) participated in the study. Joint positions and forces were measured by video cameras and rowing ergometer software, respectively. One-dimensional motion analysis was performed to calculate the power of leg drive, trunk swing, and arm pull motions. Muscle cross-sectional areas were measured using magnetic resonance imaging. Multiple regression analyses were carried out to determine the association of different muscle cross-sectional areas with partial motion power. The anterior thigh best explained the power demonstrated by leg drive (r 2 = 0.508), the posterior thigh and lower back combined best explained the power demonstrated by the trunk swing (r 2 = 0.493), and the elbow extensors best explained the power demonstrated by the arm pull (r 2 = 0.195). Other correlations, such as arm muscles with leg drive power (r 2 = 0.424) and anterior thigh with trunk swing power (r 2 = 0.335), were also significant. All muscle cross-sectional areas were associated with rowing performance either through the production of power or by transmitting work. The results imply that rowing motion requires a well-balanced distribution of muscle mass throughout the body.  相似文献   

3.
Abstract

In this study, we investigated the relationship between physiological, anthropometric, and skill qualities and playing performance in professional rugby league players. Fifty-eight high-performance rugby league players underwent measurements for anthropometry (height, body mass, sum of seven skinfolds), physiological (speed, change of direction speed, lower body muscular power, repeated-sprint ability, prolonged high-intensity intermittent running ability, and estimated maximal aerobic power), technical skill (tackling proficiency, draw and pass proficiency), and perceptual skill (reactive agility, pattern recall, pattern prediction) qualities. National Rugby League matches were coded for attacking (e.g. line breaks, try assists, etc.) and defensive (e.g. missed tackles, tackling efficiency, etc.) statistics commonly used to assess rugby league playing performance. The number of line break assists was significantly associated (P < 0.05) with greater playing experience (r = 0.36), dual-task draw and pass proficiency (r = 0.54), reactive agility (r = 0.29), and pattern recall (r = 0.32) and prediction (r = 0.28) ability, while faster speed over 40 m (r = ?0.42) was associated (P < 0.05) with a higher number of tries scored. Greater age and playing experience, better lower body muscular power, and faster 10 m and 40 m speed were significantly associated (P < 0.05) with the number of tackle attempts (positive), tackles completed (positive), and proportion of missed tackles (negative). These findings demonstrate that well-developed physical and skill qualities are associated with effective playing performance in National Rugby League players.  相似文献   

4.
This study investigated the effects of a mentally fatiguing test on physical tasks among elite cricketers. In a cross-over design, 10 elite male cricket players from a professional club performed a cricket run-two test, a Batak Lite reaction time test and a Yo-Yo-Intermittent Recovery Level 1 (Yo-Yo-IR1) test, providing a rating of perceived exertion (RPE) after completing a 30-min Stroop test (mental fatigue condition) or 30-min control condition. Perceived fatigue was assessed before and after the two conditions and motivation was measured before testing. There were post-treatment differences in the perception of mental fatigue (P < 0.001; d = ?7.82, 95% CIs = ?9.05–6.66; most likely). Cricket run-two (P = 0.002; d = ?0.51, 95% CIs = ?0.72–0.30; very likely), Yo-Yo-IR1 distance (P = 0.023; d = 0.39, 95% CIs = 0.14–0.64; likely) and RPE (P = 0.001; d = ?1.82, 95% CIs = ?2.49–1.14; most likely) were negatively affected by mental fatigue. The Batak Lite test was not affected (P = 0.137), yet a moderate (d = 0.41, 95% CIs = ?0.05–0.87) change was likely. Mental fatigue, induced by an app-based Stroop test, negatively affected cricket-relevant performance.  相似文献   

5.
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   

6.
The purpose of this study was to investigate the relationship between running economy (RE) and performance in a homogenous group of competitive Kenyan distance runners. Maximal aerobic capacity (VO2max) (68.8 ± 3.8 ml?kg?1?min?1) was determined on a motorised treadmill in 32 Kenyan (25.3 ± 5.0 years; IAAF performance score: 993 ± 77 p) distance runners. Leg anthropometry was assessed and moment arm of the Achilles tendon determined. While Achilles moment arm was associated with better RE (r2 = 0.30, P = 0.003) and upper leg length, total leg length and total leg length to body height ratio were correlated with running performance (r = 0.42, P = 0.025; r = 0.40, P = 0.030 and r = 0.38, P = 0.043, respectively), RE and maximal time on treadmill (tmax) were not associated with running performance (r = ?0.01, P = 0.965; r = 0.27; P = 0.189, respectively) in competitive Kenyan distance runners. The dissociation between RE and running performance in this homogenous group of runners would suggest that RE can be compensated by other factors to maintain high performance levels and is in line with the idea that RE is only one of many factors explaining elite running performance.  相似文献   

7.
The purpose of the study was to investigate the sensitivity of an alternative maximal accumulated oxygen deficit (MAODALT) method to discriminate the “anaerobic” capacity while comparing: least trained (LT) participants (n = 12), moderately trained (MT) participants (n = 12), endurance trained (ET) participants (n = 16), and rugby (RG) players (n = 11). Participants underwent a graded exercise test on a treadmill and a supramaximal effort for assessing MAODALT. MAODALT was calculated as the sum of oxygen equivalents from the phosphagen and glycolytic metabolic pathways. MAODALT was significantly higher (P < 0.05) in RG (64.4 ± 12.1 mL · kg?1) than in ET (56.8 ± 5.4 mL · kg?1; effect size [ES] = 0.77; +13.5%), MT (53.8 ± 5.3 mL · kg?1; ES = 1.08; +19.8%), and LT (49.9 ± 4.5 mL · kg?1; ES = 1.50; +36.4%). In addition, the magnitude-based inference analysis revealed that MAODALT was likely (LT vs. MT), very likely (MT vs. RG, and ET vs. RG) and most likely (LT vs. ET, and LT vs. RG) different between all groups, except for MT and ET, which presented an unclear difference. In conclusion, MAODALT was sensitive enough to distinguish the “anaerobic” capacity in individuals with different training status, especially for RG players compared with LT participants and MT participants.  相似文献   

8.
This study aimed to identify attributes that discriminate selected from non-selected players and predict selection into a rugby league development programme in older adolescent players. Anthropometric, performance and psychological attributes were measured in under-16 (N = 100) and under-18 (N = 60) rugby league players trialling for selection into a development programme with a professional Australian club. Sprint times (P < 0.001), predicted VO2max (P = 0.002) and push-ups1 min (P = 0.004) were superior in selected under-16 players, and sprint times (P ≤ 0.045), push-ups1 min (P < 0.001) and chin-ups1 min (P = 0.013) were superior in selected under-18 players. Further, 10-m sprint (β = ?7.706, standard error [SE] = 2.412), VO2max (β = 0.168, SE = 0.052) and body mass (β = 0.071, SE = 0.023) significantly predicted selection (R2 = 0.339) in under-16 players, while push-ups1 min (β = 0.564, SE = 0.250), 10-m sprint (β = ?68.477, SE = 28.107), body mass (β = 0.360, SE = 0.155) and chronological age (β = ?3.577, SE = 1.720) significantly predicted selection (R2 = 0.894) in under-18 players. These findings emphasise the importance of performance attributes in junior rugby league and indicate talent identification test batteries should be age-specific in older adolescent players.  相似文献   

9.
The purpose of this study was to determine whether there are differences between racial groups for body mass, stature and body mass index (BMI) in South African elite U18 rugby players and whether there were significant changes in these measurements between 2002 and 2012. Self-reported body mass and stature were obtained from U18 players (n = 4007) who attended the national tournament during this period. BMI was calculated for each player.White players were 9.8 kg heavier than black players, who were 2.3 kg heavier than coloured players (P < 0.0001). The body mass of all groups increased from 2002 to 2012 (P < 0.0001). White players were 7.0 cm taller than black players who were 0.5 cm taller than coloured players (P < 0.0001). Players’ stature measurements did not change significantly during the study period. The average BMI of white players was 0.9 kg·m?2 greater than black players who were on average 0.7 kg·m?2 greater than coloured players (P < 0.0001). The BMI of all groups changed similarly over the study period. The body mass, stature and BMI of elite under-18 rugby players in South Africa were significantly different between racial groups. This has implications for transforming the game to make it representative of the South African population.  相似文献   

10.
The aim was to compare the physical characteristics of under-18 academy and schoolboy rugby union competition by position (forwards and backs). Using a microsensor unit, match characteristics were recorded in 66 players. Locomotor characteristics were assessed by maximum sprint speed (MSS) and total, walking, jogging, striding and sprinting distances. The slow component (<2 m · s?1) of PlayerLoadTM (PLslow), which is the accumulated accelerations from the three axes of movement, was analysed as a measure of low-speed activity (e.g., rucking). A linear mixed-model was assessed with magnitude-based inferences. Academy forwards and backs almost certainly and very likely covered greater total distance than school forwards and backs. Academy players from both positions were also very likely to cover greater jogging distances. Academy backs were very likely to accumulate greater PLslow and the academy forwards a likely greater sprinting distance than school players in their respective positions. The MSS, total, walking and sprinting distances were greater in backs (likely-almost certainly), while forwards accumulated greater PLslow (almost certainly) and jogging distance (very likely). The results suggest that academy-standard rugby better prepares players to progress to senior competition compared to schoolboy rugby.  相似文献   

11.
There is limited research studying fluid and electrolyte balance in rugby union players, and a paucity of information regarding the test–retest reliability. This study describes the fluid balance of elite rugby union players across multiple squads and the reliability of fluid balance measures between two equivalent training sessions. Sixty-one elite rugby players completed a single fluid balance testing session during a game simulation training session. A subsample of 21 players completed a second fluid balance testing session during an equivalent training session. Players were weighed in minimal clothing before and after each training session. Each player was provided with their own drinks which were weighed before and after each training session. More players gained body weight (9 (14.8%)) during training than lost greater than 2% of their initial body mass (1 (1.6%)). Pre-training body mass and rate of fluid loss were significantly associated (r?=?0.318, p?=?.013). There was a significant correlation between rate of fluid loss in sessions 1 (1.74?±?0.32?L?h?1) and 2 (1.10?±?0.31?L.?h?1), (r?=?0.470, p?=?.032). This could be useful for nutritionists working with rugby squads to identify players with high sweat losses.  相似文献   

12.
Spinal cord injury (SCI) derives in loss of bone mineral content (BMC) and bone mineral density (BMD). However, physical activity is an important determinant in bone mass acquisition, which is partially mediated through the lean mass (LM). The aim was to examine the effect of cardiorespiratory fitness (CRF) on BMD and BMC arms of adult males with SCI and able-bodied controls using the arm LM as a mediator variable. Thirty able-bodied men and thirty men with SCI participated. BMC and BMD were analysed by DXA, and indirect calorimetry was used to calculate VO2peak during a progressive arm-cranking test. When groups were divided by the amount of LM, the subgroup with highest LM had significantly higher arm BMC compared to the lowest LM subgroup (p ≤ 0.05) in both SCI and able-bodied groups. Moreover, same differences were found when confidence intervals were analysed. Only in the SCI group, arm LM mediated the relationship between bone mass and CRF at 30.9%, as indicated by the Sobel test (z = 2.17 and z = 2.04 for BMC and BMD, respectively). In conclusion, LM mediates the indirect association between CRF and bone health, specifically in the arms. This finding highlights the importance of having an adequate CRF for the maintenance of good bone health in SCI men.  相似文献   

13.
Abstract

We compared the match activity profiles of elite footballers from Australian football (AF), rugby league (RL) and soccer (SOC), using identical movement definitions. Ninety-four elite footballers from AF, RL or SOC clubs in Australia participated in this study. Movement data were collected using a 5-Hz global positioning system from matches during the 2008–2011 competitive seasons, including measures of velocity, distance, acceleration and bouts of repeat sprints (RS). Australian footballers covered the greatest relative running distances (129 ± 17 m.min?1) compared to RL (97 ± 16 m.min?1) and SOC (104 ± 10 m.min?1) (effect size [ES]; 1.0–2.8). The relative distance covered (4.92 ± 2.10 m.min?1 vs. 5.42 ± 2.49 m.min?1; 0.74 ± 0.78 m.min?1 vs. 0.97 ± 0.80 m.min?1) and the number of high-velocity running (0.4 ± 0.2 no.min?1 vs. 0.4 ± 0.2 no.min?1) and sprint (0.06 ± 0.06 no.min?1 vs. 0.08 ± 0.07 no.min?1) efforts between RL and SOC players were similar (ES; 0.1–0.3). Rugby league players undertook the highest relative number of accelerations (1.10 ± 0.56 no.min?1). RS bouts were uncommon for all codes. RL and SOC players perform less running than AF players, possibly due to limited open space as a consequence of field size and code specific rules. While training in football should be code specific, there may be some transference of conditioning drills across codes.  相似文献   

14.
Limited research has compared the physical qualities of adolescent rugby union (RU) players across differing playing standards. This study therefore compared the physical qualities of academy and school Under-18 RU players. One-hundred and eighty-four (professional regional academy, n = 55 school, n = 129) male RU players underwent a physical testing battery to quantify height, body mass, strength (bench press and pull-up), speed (10, 20 and 40 m), 10 m momentum (calculated; 10 m velocity * body mass) and a proxy measure of aerobic fitness (Yo-Yo Intermittent Recovery Test Level 1; IRTL1). The practical significance of differences between playing levels were assessed using magnitude-based inferences. Academy players were taller (very likely small), heavier (likely moderate) and stronger (bench press possibly large; pull-up plus body mass likely small) than school players. Academy players were faster than school players over 20 and 40 m (possibly and likely small), although differences in 10 m speed were not apparent (possibly trivial). Academy players displayed greater 10 m momentum (likely moderate) and greater IRTL1 performance (likely small) than school players. These findings suggest that body size, strength, running momentum, 40 m speed and aerobic fitness contribute to a higher playing standard in adolescent rugby union.  相似文献   

15.
The purpose of this study was to determine the kinematic patterns that maximized the vertical force produced during the water polo eggbeater kick. Twelve water polo players were tested executing the eggbeater kick with the trunk aligned vertically and with the upper limbs above water while trying to maintain as high a position as possible out of the water for nine eggbeater kick cycles. Lower limb joint angular kinematics, pitch angles and speed of the feet were calculated. The vertical force produced during the eggbeater kick cycle was calculated using inverse dynamics for the independent lower body segments and combined upper body segments, and a participant-specific second-degree regression equation for the weight and buoyancy contributions. Vertical force normalized to body weight was associated with hip flexion (average, r = 0.691; maximum, r = 0.791; range of motion, r = 0.710), hip abduction (maximum, r = 0.654), knee flexion (average, r = 0.716; minimum, r = 0.653) and knee flexion-extension angular velocity (r = 0.758). Effective orientation of the hips resulted in fast horizontal motion of the feet with positive pitch angles. Vertical motion of the feet was negatively associated with vertical force. A multiple regression model comprising the non-collinear variables of maximum hip abduction, hip flexion range of motion and knee flexion angular velocity accounted for 81% of the variance in normalized vertical force. For high performance in the water polo, eggbeater kick players should execute fast horizontal motion with the feet by having large abduction and flexion of the hips, and fast extension and flexion of the knees.  相似文献   

16.
Abstract

Leg stiffness is a modifiable mechanical property that may be related to soft tissue injury risk. The purpose of this study was to examine mean leg stiffness and bilateral differences in leg stiffness across an entire professional Australian Football League (AFL) season, and determine whether this parameter was related to the incidence of lower body soft tissue injury. The stiffness of the left and right legs of 39 professional AFL players (age 24.4 ± 4.4 years, body mass 87.4 ± 8.1 kg, stature 1.87 ± 0.07 m) was measured using a unilateral hopping test at least once per month throughout the season. Injury data were obtained directly from the head medical officer at the football club. Mean leg stiffness and bilateral differences in leg stiffness were compared between the injured and non-injured players. There was no difference between the season mean leg stiffness values for the injured (219.3 ± 16.1 N · m?1 · kg?1) and non-injured (217.4 ± 14.9 N · m?1 · kg?1; P = 0.721) groups. The injured group (7.5 ± 3.0%) recorded a significantly higher season mean bilateral difference in leg stiffness than the non-injured group (5.5 ± 1.3%; P = 0.05). A relatively high bilateral difference in leg stiffness appears to be related to the incidence of soft tissue injury in Australian football players. This information is of particular importance to medical and conditioning staff across a variety of sports.  相似文献   

17.
Purpose: There is demand in applied sport settings to measure recovery briefly and accurately. Research indicates mood disturbance as the strongest psychological predictor of mental and physical recovery. The Brief Assessment of Mood (BAM) is a shortened version of the Profile of Mood States that can be completed in less than 30 s. The purpose of this study was to examine the BAM as a quick measure of mood in relation to recovery status in elite rugby players alongside established physiological markers of recovery. Method: Using elite rugby union players (N = 12), this study examined the utility of BAM as an indicator of mental and physical recovery in elite athletes by exploring pattern change in mood disturbance, energy index, power output, cortisol, and testosterone 36 hr before and 12 hr, 36 hr, and 60 hr after a competitive rugby match. Results: Repeated-measures multivariate analysis of variance indicated significant changes in all variables across the 4 time points (p < .05, η2 range = .20–.48), concurrent with previous study findings. Although visual inspection of the graphs indicated that the pattern of change for mood disturbance and energy index mapped changes in all physiological variables, only a low correlation was observed for power output (r = ? .34). Conclusions: Although BAM scores changed significantly over time in accordance with the hypotheses, further testing is required to confirm the utility of the BAM as a measure of recovery. The results indicate that the BAM could be used as 1 indicator of recovery status alongside other measures.  相似文献   

18.
Abstract

In this study, we investigated the effect of ingesting carbohydrate alone or carbohydrate with protein on functional and metabolic markers of recovery from a rugby union-specific shuttle running protocol. On three occasions, at least one week apart in a counterbalanced order, nine experienced male rugby union forwards ingested placebo, carbohydrate (1.2 g · kg body mass?1 · h?1) or carbohydrate with protein (0.4 g · kg body mass?1 · h?1) before, during, and after a rugby union-specific protocol. Markers of muscle damage (creatine kinase: before, 258 ± 171 U · L?1 vs. 24 h after, 574 ± 285 U · L?1; myoglobin: pre, 50 ± 18 vs. immediately after, 210 ± 84 nmol · L?1; P < 0.05) and muscle soreness (1, 2, and 3 [maximum soreness = 8] for before, immediately after, and 24 h after exercise, respectively) increased. Leg strength and repeated 6-s cycle sprint mean power were slightly reduced after exercise (93% and 95% of pre-exercise values, respectively; P < 0.05), but were almost fully recovered after 24 h (97% and 99% of pre-exercise values, respectively). There were no differences between trials for any measure. These results indicate that in experienced rugby players, the small degree of muscle damage and reduction in function induced by the exercise protocol were not attenuated by the ingestion of carbohydrate and protein.  相似文献   

19.
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20.
Diagonal skiing as a major classical technique has hardly been investigated over the last two decades, although technique and racing velocities have developed substantially. The aims of the present study were to 1) analyse pole and leg kinetics and kinematics during submaximal uphill diagonal roller skiing and 2) identify biomechanical factors related to performance. Twelve elite skiers performed a time to exhaustion (performance) test on a treadmill. Joint kinematics and pole/plantar forces were recorded separately during diagonal roller skiing (9°; 11 km/h). Performance was correlated to cycle length (r = 0.77; P < 0.05), relative leg swing (r = 0.71), and gliding time (r = 0.74), hip flexion range of motion (ROM) during swing (r = 0.73) and knee extension ROM during gliding (r = 0.71). Push-off demonstrated performance correlations for impulse of leg force (r = 0.84), relative duration (r = ? 0.76) and knee flexion (r = 0.73) and extension ROM (r = 0.74). Relative time to peak pole force was associated with performance (r = 0.73). In summary, diagonal roller skiing performance was linked to 1) longer cycle length, 2) greater impulse of force during a shorter push-off with larger flexion/extension ROMs in leg joints, 3) longer leg swing, and 4) later peak pole force, demonstrating the major key characteristics to be emphasised in training.  相似文献   

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