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1.
Abstract

Bioelectrical impedance spectroscopy (BIS) provides an affordable and practical assessment of fat-free mass (FFM). However, little information is available on the assessment of changes in fat-free mass in top-level athletes using BIS. The aim of this study was to examine the accuracy of BIS in tracking changes in fat-free mass of elite male judo athletes from a period of weight stability to just before competition, using the four-compartment model (4C model) as reference method. In total, 27 elite male judo athletes (age 22.2 ± 2.8 years) were evaluated. Measures of body volume assessed by air displacement plethysmography, bone mineral content by dual-energy X-ray absorptiometry, and total-body water assessed with deuterium dilution were used in a 4C model. Fat-free mass was also assessed by BIS (FFMBIS). Changes in FFMBIS were not significantly different from measured by the reference method (P = 0.000). Furthermore, the r 2 was 0.62 and the standard error of the estimate was 1.03 kg. The limits of agreement ranged from ?3.36 to 2.59 kg with no bias observed. These findings demonstrate the viability of BIS as a valid tool for tracking fat-free mass in elite male judo athletes. However, based on the wide limits of agreement observed, BIS is less valid at an individual level for tracking fat-free mass in these athletes.  相似文献   

2.
Abstract Bioelectrical impedance spectroscopy (BIS) provides an affordable and practical assessment of fat-free mass (FFM). However, little information is available on the assessment of changes in fat-free mass in top-level athletes using BIS. The aim of this study was to examine the accuracy of BIS in tracking changes in fat-free mass of elite male judo athletes from a period of weight stability to just before competition, using the four-compartment model (4C model) as reference method. In total, 27 elite male judo athletes (age 22.2?±?2.8 years) were evaluated. Measures of body volume assessed by air displacement plethysmography, bone mineral content by dual-energy X-ray absorptiometry, and total-body water assessed with deuterium dilution were used in a 4C model. Fat-free mass was also assessed by BIS (FFM(BIS)). Changes in FFM(BIS) were not significantly different from measured by the reference method (P?=?0.000). Furthermore, the r (2) was 0.62 and the standard error of the estimate was 1.03 kg. The limits of agreement ranged from -3.36 to 2.59 kg with no bias observed. These findings demonstrate the viability of BIS as a valid tool for tracking fat-free mass in elite male judo athletes. However, based on the wide limits of agreement observed, BIS is less valid at an individual level for tracking fat-free mass in these athletes.  相似文献   

3.
Abstract

In the present study, we examined mood changes following dancing. Previous works suggested that contextual factors may influence affective states; it has been shown that changes in mood following competition differ from those following recreational exercise. The study has been conducted in Warsaw, Poland. Mood was assessed before and after dance activity in three groups of ballroom dancers: recreational (n = 32) and competitive (n = 38) dancers doing ordinary training and competitive dancers taking part in a dance competition (n = 35). We observed a moderately positive change in recreational dancers doing ordinary training; they reported higher energetic arousal (EA) and hedonic tone (HT) and lower tense arousal (TA) after dance activity. In comparison dancers taking part in a competition were higher on TA before dancing and felt less pleasure after dancing than recreational and competitive dancers doing ordinary training; HT, TA and EA moderately decreased during competition. In general, the current study suggests that dance can elicit changes in mood; however, situational context has to be taken into consideration when explaining the influence of dance on mood.  相似文献   

4.
β-hydroxy-β-methylbutyrate (calcium: HMB-Ca and free acid: HMB-FA) and α-hydroxyisocaproic acid (α-HICA) are leucine metabolites that have been proposed to improve body composition and strength when combined with resistance exercise training (RET). In this double-blind randomized controlled pragmatic trial, we evaluated the effects of off-the-shelf supplements: α-HICA, HMB-FA and HMB-Ca, on RET-induced changes in body composition and performance. Forty men were blocked randomized to receive α-HICA (n?=?10, fat-free mass [FFM]?=?62.0?±?7.1?kg), HMB-FA (n?=?11, FFM?=?62.7?±?10.5?kg), HMB-Ca (n?=?9, FFM?=?65.6?±?10.1?kg) or placebo (PLA; n?=?10, FFM?=?64.2?±?5.7?kg). The training protocol consisted of a whole-body resistance training routine, thrice weekly for 8 weeks. Body composition was assessed by dual-energy x-ray absorptiometry (DXA) and total body water (TBW) by whole-body bioimpedance spectroscopy (BIS), both at baseline and at the end of weeks 4 and 8. Time-dependent changes were observed for increase in trunk FFM (p?相似文献   

5.
Abstract

Quiet eye (QE) is a robust phenomenon in golf putting and expert players frequently demonstrate longer QE periods (i.e., the final fixation prior to the onset of the putting motion) relative to their less-skilled counterparts. In this experiment we used a pre-test/post-test design to determine whether we could use novel training aids and instructions to elicit acute changes in QE behaviour after a brief intervention. Three techniques were used: a marker under the ball, a hole-focus instruction, and a novel putting device – the putting box of science (PBoS). We compared gaze behaviour before and after 30 practice putts and found significant changes in QE duration in the absence of concomitant changes in putting performance. The control (?18 ms) and PBoS (+198 ms) groups did not change, the hole-focus group (?287 ms) had a decrease in QE duration, and the marker group (+366 ms) increased in QE duration. These finding are discussed relative to current QE training programs and the implications for development of evidence-based training aids with coach consultation.  相似文献   

6.
This study examined temporal trends in home advantage in the top two English football divisions and used change point analysis to test the hypothesis that home advantage has not remained constant over time. Regression analysis was used to model the impact of substitutions (a proxy for "information transfer") and the points system on home advantage. The results suggest that changing from two points for a win to three points for a win has led to a 0.39 reduction (95% confidence interval=0.21 to 0.56) in the ratio of home wins to away wins. Increasing the number of substitutions is associated with a small increase in the ratio of home wins to away wins, although this is not statistically significant. The evidence indicates that, in this particular context, the extent of home advantage has diminished. This contradicts most other published work, which suggests that home advantage is stable over time. I argue that this reduction is more likely to be the result of the introduction of three points for a win, which has lessened the incentives for away teams to settle for a draw, than an increase in "information transfer". Research into temporal trends in home advantage is interesting in its own right but might, in addition, shed light on determinants of the home advantage phenomenon.  相似文献   

7.
Abstract

The aim of this experiment was to analyse the consequences of changing attitudes related to doping through thoughtful versus non-thoughtful processes. Participants were young soccer players. They received a persuasive message either against or in favour of the legalisation of several doping behaviours in soccer (e.g., the use of anabolic androgenic steroid – AAS), and participants' level of elaboration (i.e., deliberative thinking) was manipulated in two different experimental (high vs. low) conditions. Attitudes towards the legalisation proposal were assessed immediately following the message and one week later. Results showed attitude change was a function of message direction and was relatively equivalent for both high and low elaboration participants immediately after reading the message. That is, those who received the message against legalisation showed significantly more unfavourable attitudes towards the proposal than did those who received the message in favour of legalisation regardless of the extent of elaboration. However, attitude change was found to be persistent only for high elaboration participants one week after message exposure. In the present paper, we discuss implications of changing attitudes related to doping depending on whether the change occurred through psychological processes that require either extensive or small amounts of deliberative thinking and elaboration.  相似文献   

8.
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9.
This study examined the influence of differing volume load and intensity (%1 repetition maximum[%1RM]) resistance exercise workouts on session rating of perceived exertion (sRPE) countermovement jump (CMJ) performance and endocrine responses. Twelve participants performed a workout comprising four exercises (bench press, back squat, deadlift and prone bench pull) in randomised order as either power (POW); 3 sets × 6 repetitions at 45%1RM × 3 min inter-set rest, strength (ST); 3 sets × 3 repetitions at 90%1RM × 3 min inter-set rest, or hypertrophy (HYP); 3 sets × 10 repetitions at 70%1RM × 1 min inter-set rest in a randomised-crossover design. CMJ performance and endocrine responses were measured immediately pre-, post-, 12, 24, 48 and 72 h post-exercise. POW sRPE (3.0 ± 1.0) was lower than ST (4.5 ± 1.0) (P = 0.01), and both were lower than HYP (8.5 ± 1.0) (P = 0.01). Duration of CMJ decrement was longer (P ≤ 0.05) for HYP (72 h) compared to POW (12 h) and ST (24 h). Testosterone concentration was greater (P ≤ 0.05) immediately post-exercise in HYP compared to POW and ST. In conclusion, less inter-set rest, greater volume load and intensity (%1RM) may increase sRPE, duration of CMJ performance decrement and testosterone responses in resistance exercise.  相似文献   

10.
Three issues are put forward with respect to the active participation of young people in leisure-time sports styles. It is considered (a) whether sports participation styles can be detected over the last three decades, (b) whether they have changed in this period of time, and (c) whether traditional parameters understood as structuring and positioning young people's lifestyles are still relevant with respect to their sports participation preferences. Youth sports participation data were retrieved from four large-scale surveys in 1969, 1979, 1989 and 1999 (Ntotal=22,424 high school boys and girls). These data allow for a time trend analysis of youth sports participation styles. Results from component and regression analyses indicate that different participation styles can be distinguished for each period of time and that these styles have been developing and differentiating through a growing responsiveness to wider social trends. Structural and positioning variables such as age, sex and education remain significant determinants for young people's active participation in leisure-time sports styles over the observed period of time. Although these social structures continue to shape youth sports participation styles, it is suggested that there is more variety within social groups than among social groups partially due to processes of individualisation and homogenisation.  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.
PurposeThis study aimed to investigate if changing the midsole bending stiffness of athletic footwear can affect the onset of lower limb joint work redistribution during a prolonged run.MethodsFifteen trained male runners (10-km time of <44 min) performed 10-km runs at 90% of their individual speed at lactate threshold (i.e., when change in lactate exceeded 1 mmol/L during an incremental running test) in a control and stiff shoe condition on 2 occasions. Lower limb joint kinematics and kinetics were measured using a motion capture system and a force-instrumented treadmill. Data were acquired every 500 m.ResultsProlonged running resulted in a redistribution of positive joint work from distal to proximal joints in both shoe conditions. Compared to the beginning of the run, less positive work was performed at the ankle (approximately 9%; p ≤ 0.001) and more positive work was performed at the knee joint (approximately 17%; p ≤ 0.001) at the end of the run. When running in the stiff shoe condition, the onset of joint work redistribution at the ankle and knee joints occurred at a later point during the run.ConclusionA delayed onset of joint work redistribution in the stiff condition may result in less activated muscle volume, because ankle plantar flexor muscles have shorter muscles fascicles and smaller cross-sectional areas compared to knee extensor muscles. Less active muscle volume could be related to previously reported decreases in metabolic cost when running in stiff footwear. These results contribute to the notion that footwear with increased stiffness likely results in reductions in metabolic cost by delaying joint work redistribution from distal to proximal joints.  相似文献   

13.
To examine whether performance, physiological and perceptual responses to repeated sprints including changes of direction are angle-dependent, twelve team-sport players performed (1) single 30-m sprints without or with two (45°, 90° or 135°) changes of direction and (2) repeated-sprint sequences matched for initial sprint time without (Line [6x30m]) or with (45° [6x28.0m], 90° [6x22.2m] or 135° [6x19.5m]) two changes of direction. For each sequence, mean sprint time (RS(mean)), peak heart rate (HR(peak)), blood lactate concentration (Δ[La](b)) and rating of perceived exertion (RPE) were recorded. Results show that performance, physiological and perceptual responses were angle-dependent. Compared with Line, RS(mean) was likely lower for 45? (-1.7%(90%CL:-3.5;0.1); chances for greater/similar/lower values of 1/23/76%, respectively) and possibly greater for 135? (+0.8%(90%CL:-0.6;2.3), 44/53/3%). HR(peak), Δ[La](b) and RPE were likely greater for Line compared with the three other protocols. RPE during 45? was greater than during 90?(+14%(90%CL:8;19), 0/1/99%) and 135? (+11%(90%CL:1;22), 2/15/83%). The correlation coefficients describing the relationships between the four single 30-m sprints were <0.70; these for RS(mean) times were >0.70. Performance, physiological and perceptual response during repeated sprints with changes of direction are angle-dependent. However, unlike changes of direction speed, repeated-sprint ability with changes of direction is more likely to be a general quality.  相似文献   

14.
Previous data have indicated relative stability over time of paediatric jumping performance, but few data exist since the early 2000s. This study quantified the 30-year secular changes in jumping performance of Australian children aged 11?12-years using data from the Australian Schools Health and Fitness Survey (1985, n = 1967) and Growing Up in Australia’s Child Health CheckPoint (2015, n = 1765). Both cohorts measured jumping performance (standing long jump distance), anthropometric and demographic data. Secular changes in jumping performance means and quantiles were examined using multivariable linear and quantile regression. Between 1985 and 2015, jumping performance declined by 16.4 cm or by 11.2% (standardised change 0.66 SD, 95%CI 0.60 to 0.73). Adjustment for body mass reduced the effect by 32%, although the decline remained (absolute change – 11.1 cm, 95%CI ?12.5 to ?9.7; percent change 7.7%, 95%CI 6.7 to 8.6; standardised change 0.51 SD, 95%CI 0.44 to 0.57). This decline was evident across all quantiles. The jumping performance of Australian children aged 11?12-years has declined between 1985 and 2015, with body mass changes accounting for only part of the decline. Efforts should continue to promote paediatric muscular fitness, reduce adiposity, and aim to reverse this decline in jumping performance.  相似文献   

15.
This paper focuses mainly on a the author's current experience of Higher Education and of a module concerned with gender, difference, sport and leisure made available to students studying for sport and leisure management degrees. It reviews the changed nature of the curriculum in the shifting socio-economic climate, suggesting that the neo-liberal1 turn influencing Higher Education in UK is reinforcing an organisational (university) culture which is counter productive to fostering critical gender and race awareness in both staff and students within restructured sport management programs. The approach I adopt in writing this paper is partly auto/ethnographic and as such, on occasion, it looks at the previous research and current experiences through the eyes and emotions of a senior woman academic located within a changing ‘new’ university culture. Auto/ethnography as research approach and autobiography as learning medium are considered. Like this abstract, I move in and out of centring myself in the text whilst interweaving writing in a more neutral ‘academic’ form.  相似文献   

16.
BackgroundEvery high-level athlete will eventually see his or her sport career come to an end. Most former athletes will experience changes in their self-definition and everyday behaviors as they accept a nonathletic way of life. The present study aimed to identify discrepancies between actual and former athletes regarding athletic identity, physical activity (PA), and nutrition habits.MethodsActual athletes (AA; n = 122), former athletes (FA; n = 230), and nonathletes (NA; n = 74) were asked to complete an online questionnaire on athletic identity, duration and intensity levels of occupational and leisure time PA, and nutritional habits.ResultsFA healthy nutrition score was the lowest of the 3 groups and significantly different from that of AA. Athletic identity and intense and moderate PA during leisure time consistently decreased (p < 0.01) across the 3 groups (AA > FA > NA). No significant difference between FA and NA was found regarding either nutritional habits or type of PA.ConclusionSport retirement may affect FA quality of nutritional habits that tends to decline below the NA level, as well as the amount of time spent practicing physical activities during leisure time. Athletic status does not ensure PA practice during sport postcareer.  相似文献   

17.
~~ Barcelona double champion GuoJingjing is set to spearhead Chinesewomen's charge towards Olympic glory. Recovering from an ankle injuryincurred during the winter training camp,Guo has kept a low key about her Olympicgold expectations after her doubledisappointments in Sydney, losing toteammate Fu Mingxia in the individualevent and surrendering synchronized titleto Russian pair Vera Ilina and IouliaPakhalina, who are also hot favorites forboth the individual and synchronizedevents asid…  相似文献   

18.
Hand in Hand     
~~Hand in Hand~~  相似文献   

19.
in the NBA     
  相似文献   

20.
欧洲杯in Side     
１．在１９９２年欧锦赛预选赛中,法罗群岛不得不将他们首次参加这一赛事的四场主场比赛移到瑞典去打,因为他们的赛场草皮都是中看不能用的人造的假草皮。 ２．热刺队的中场球员Ａｌｌａｎ·Ｍｕｌｌｅｒｙ是英格兰队在国际比赛历史上第一位被罚下场的球员,当时是在１９６８年欧锦赛半决赛英格兰对南斯拉夫比赛中。 ３． １９９５年欧锦赛预选赛阿尔巴尼亚与斯洛文尼亚的比赛中,只有５０名观众到场观看。 ４．在获得１９８８年欧锦赛冠军荷兰队队中,有５人留有小胡子,也许这使他们看起来更漂亮一些。（其中有古力特、里杰卡尔德,猜猜…  相似文献   

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