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1.
Triathlon competitions are performed over markedly different distances and under a variety of technical constraints. In 'standard-distance' triathlons involving 1.5km swim, 40km cycling and 10km running, a World Cup series as well as a World Championship race is available for 'elite' competitors. In contrast, 'age-group' triathletes may compete in 5-year age categories at a World Championship level, but not against the elite competitors. The difference between elite and age-group races is that during the cycle stage elite competitors may 'draft' or cycle in a sheltered position; age-group athletes complete the cycle stage as an individual time trial. Within triathlons there are a number of specific aspects that make the physiological demands different from the individual sports of swimming, cycling and running. The physiological demands of the cycle stage in elite races may also differ compared with the age-group format. This in turn may influence performance during the cycle leg and subsequent running stage. Wetsuit use and drafting during swimming (in both elite and age-group races) result in improved buoyancy and a reduction in frontal resistance, respectively. Both of these factors will result in improved performance and efficiency relative to normal pool-based swimming efforts. Overall cycling performance after swimming in a triathlon is not typically affected. However, it is possible that during the initial stages of the cycle leg the ability of an athlete to generate the high power outputs necessary for tactical position changes may be impeded. Drafting during cycling results in a reduction in frontal resistance and reduced energy cost at a given submaximal intensity. The reduced energy expenditure during the cycle stage results in an improvement in running, so an athlete may exercise at a higher percentage of maximal oxygen uptake. In elite triathlon races, the cycle courses offer specific physiological demands that may result in different fatigue responses when compared with standard time-trial courses. Furthermore, it is possible that different physical and physiological characteristics may make some athletes more suited to races where the cycle course is either flat or has undulating sections. An athlete's ability to perform running activity after cycling, during a triathlon, may be influenced by the pedalling frequency and also the physiological demands of the cycle stage. The technical features of elite and age-group triathlons together with the physiological demands of longer distance events should be considered in experimental design, training practice and also performance diagnosis of triathletes.  相似文献   

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The increasing acceptance of ten-pin bowling as a sport, as well as the keen competition amongst bowlers, necessitates the identification of performance indicators to aid training. The aim of this cross-sectional study was to determine if age, height, weight, aerobic power index, bowling grip strength, 10-RM leg press performance, and the sit-and-reach distance correlated with bowling performance in 42 elite bowlers (26 males and 16 females). At the same time, the physiological profiles of bowlers classified as heavy ball strokers, heavy ball crankers, and light ball spinners were compared. The results showed that for the male bowlers, none of the parameters correlated with performance, while for the female bowlers, the only parameter that correlated with performance was the aerobic power index. Bowlers using the three different releases had similar anthropometric and physiological profiles. The implications from this study are that bowlers of diverse age and build can be equally competitive in the sport; that aerobic capacity (as reflected by the aerobic power index) may, to a certain extent, contribute to bowling performance; and that strength and flexibility measures do not seem to be useful performance indicators amongst elite bowlers.  相似文献   

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The aim of this study was to compare the arm-leg coordination in flat breaststroke among four groups of swimmers (elite males, elite females and non-elite males, non-elite females) of two different competitive levels. Using a velocity-video system, both forward acceleration and deceleration phases of the hip were first identified. Based on these phases, four temporal gaps indicated the time duration between arm and leg actions throughout three race paces (200, 100, and 50 m). For both groups, a velocity increase was combined with an increase of stroke rate, a decrease of stroke length, and an increase of the propulsive phases and a decrease of the glide phases. However, when the relative duration of one stroke cycle was considered, the elite swimmers had significant shorter time of the glide phase than lower competitive level swimmers (18.80 % vs. 31.04 % for females and 11.89 % vs. 19.60 % for males) combined with a longer stroke length (respectively 2.05 m vs. 1.73 m and 2.03 m vs. 1.82 m). Furthermore, the temporal gaps of the elite swimmers showed a greater continuity in the arm and leg actions, which indicates a better timing than non-elite swimmers. It was concluded that elite breaststroke swimmers are able to optimise their propulsion by reducing their glide phase and using a more continuous timing between arm and leg coordination.  相似文献   

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This study examined the effect of heat stress on physiological responses and exercise performance in elite road cyclists. Eleven members of the Australian National Road Cycling Squad completed two 30 min cycling time-trials in an environmental chamber set at either 32 degrees C, (HT) or 23 degrees C (NT) with a relative humidity of 60% in each circumstance. The trials were separated by two days, with six subjects performing HT first. Power output was 6.5% lower (P<0.05) during HT compared with NT. Mean skin temperature and sweat rate were higher (P<0.05) in HT compared with NT. In contrast, rectal temperature was remarkably similar throughout each trial. During the first 10 min of exercise in HT when power output was not different between trials, blood lactate was higher (P<0.05), and blood pH lower (P<0.05). In contrast, during the last 10 min of exercise when power output was reduced (P<0.05), blood lactate was lower (P<0.05), and pH higher (P<0.05), in HT. These data indicate that heat stress is associated with a reduced power output during self-paced exercise in highly trained men. This decrease in performance appears to be associated with factors associated with body temperature rather than metabolic capacity.  相似文献   

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This study investigated whether pacing differed between 68 male and 35 female triathletes competing over the same ITU World Cup course. Swimming, cycling and running velocities (m s(-1) and km h(-1)) were measured using a global positioning system (Garmin, UK), video analysis (Panasonic NV-MX300EG), and timing system (Datasport, Switzerland). The relationship between performance in each discipline and finishing position was determined. Speed over the first 222 m of the swim was associated with position (r=-0.88 in males, r=-0.97 in females, both p<0.01) and offset from the leader, at the swim finish (r=-0.42 in males, r=-0.49 in females, both p<0.01). The latter affected which pack number was attained in bike lap 1 (r=0.81 in males, r=0.93 in females, both p<0.01), bike finishing position (both r=0.41, p<0.01) and overall finishing position (r=0.39 in males, r=0.47 in females, both p<0.01). Average biking speed, and both speed and pack attained in bike laps 1 and 2, influenced finishing position less in the males (r=-0.42, -0.2 and -0.42, respectively, versus r=-0.74, -0.75, and -0.72, respectively, in the females, all p<0.01). Average run speed correlated better with finishing position in males (r=-0.94, p<0.01) than females (r=-0.71, p<0.001). Both sexes ran faster over the first 993 m than most other run sections but no clear benefit of this strategy was apparent. The extent to which the results reflect sex differences in field size and relative ability in each discipline remains unclear.  相似文献   

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This study examined the consequences of performance in swim, cycle, and run phases on overall race finish in an elite "draft legal" Olympic distance (OD) triathlon. The subjects were 24 male athletes grouped by rank order into the top 50 % (n = 12) and bottom 50 % (n = 12) of the race population. Swimming velocity (m x s (-1)), cycling speed (km x h (-1)), and running velocity (m x s (-1)) were measured at regular intervals using a global positioning system, chip timing system, and video analysis. Actual rank after each stage and overall was obtained from the race results and video analysis. The top 50 % athletes overall swam faster over the first 400 m of the swim phase (p > 0.05). Their swim ranking was lower (p < 0.01) than the bottom 50 % athletes after this stage. There were no significant differences in actual race position between the groups after the cycle. However, the bottom 50 % athletes after the swim stage cycled faster (p < 0.01) at 13.4 km of the cycle. Speed at 13.4 km of the cycle stage was inversely correlated (r = 0.60, p < 0.01) to running performance. Performance (rank and velocity) in the running stage was highly correlated with overall race result (r = 0.86 and - 0.53, respectively, both p > 0.01). It appears that inferior swimming performance can result in a tactic that involves greater work in the initial stages of the cycle stage of elite OD racing, and may influence subsequent running performance.  相似文献   

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Given increasing popularity of triathlon, the objective of this study was to evaluate the acute effects upon the health of triathletes. To do so, with a sample of 23 male athletes (34.4 ± 7.9 years old), an assessment was carried out both before and after an Olympic distance triathlon, of the bodily composition, the jumping ability and the BORG and VAS scales, as well as a blood analysis of the following: Lactate (mmol/L), Hematrocrit (%), Glucose (mg/dL), Total proteins (mg/dL), Triglycerides (mg/dL), Bilirubin (mg/dL), GOT (IU/L), GPT (IU/L), LDH (IU/L), CPK (IU/L). The results showed an increase (p < 0.001) in the different markers of metabolic stress and muscular damage following the triathlon, but always within a normal range considered to be healthy, with the exception of CPK (IU/L) (PRE 149.33 ± 108.16 vs POST 290.10 ± 102.48). Therefore, it would seem that competing in an Olympic-distance triathlon does not pose health risks for trained subjects.  相似文献   

9.
Cardiovascular and thermal responses of triathlon performance   总被引:4,自引:0,他引:4  
Triathletes typically train each triathlon event separately. Therefore, to determine the cardiovascular and thermal differences between training and triathlon performance, nine male triathletes performed a simulated 75-min (40 km) control bike and a 40-min (10 km) control run at 70% of maximal oxygen uptake. Control data were compared to data derived from a simulated triathlon (0.8-km swim, 75-min bike, and 40-min run). Results demonstrated that prior swimming significantly decreased (P less than 0.05) triathlon cycling work output (191 +/- 4.2 to 159 +/- 7.6 W) producing mean differences (P less than 0.05) in oxygen uptake (3.18 +/- 0.1 to 3.01 +/- 0.11.min-1), ventilation (84.7 +/- 4 to 80.4 +/- 4.21.min-1), stroke volume (128 +/- 7.1 to 118 +/- 3.5 ml.min-1), cardiac output (20.7 +/- 1.2 to 18.9 +/- 0.8 l.min-1), mean arterial pressure (105 +/- 3.8 to 96 +/- 7.9 mm Hg) and rectal temperature (38.2 +/- 0.2 to 38.4 +/- 0.3 degrees C). Triathlon running, while performing identical control work output, elicited significant increases (P less than 0.05) in oxygen uptake (3.41 +/- 0.1 to 3.85 +/- 0.1 l.min-1), ventilation (91.3 +/- 3.3 to 104.2 +/- 2.8 l.min-1), heart rate (161 +/- 3.1 to 174 +/- 3.6 beats.min-1), arteriovenous oxygen difference (15.3 +/- 0.2 to 17.2 +/- 0.3 ml.100 ml-1) and rectal temperature (38.3 +/- 0.2 and 39.2 +/- 0.3 degrees C) with significantly lower (P less than 0.05) stroke volume (138 +/- 2.4 to 129 +/- 3.6 ml.min-1) and mean arterial pressure (102 +/- 11.2 to 89 +/- 5.5 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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The purpose of this study was to determine whether seasonal deterioration in physiological variables could be observed in skiers. Eighteen international male British downhill, free-style, and speed skiers were subjected to a maximal treadmill running test, a 30-s Wingate test, and isokinetic dynamometry at the beginning, middle, and end of the 1989-90 competition season. Maximal oxygen intake (VO2max) and respiratory anaerobic threshold (T vent) were among the parameters measured on the treadmill test, while peak and mean power outputs were measured during the Wingate test. During dynamometry, knee flexors and extensors were bilaterally assessed at 1.04 and 3.14 rad.s-1. Mean VO2max (p < 0.01) and mean T vent (p < 0.05) were lower at the end compared to the beginning, but not compared to the middle of the competition season. The isokinetic test demonstrated lower mean peak torques at 1.04 rad.s-1, for the knee extensors measured at the end of the season, compared with both the start (p < 0.01) and the middle (p < 0.05). Also at 1.04 rad.s-1, knee flexors produced lower torques at the end than the start of the season (p < 0.05). No further statistical differences were found. It was concluded that seasonal deterioration in key physiological variables such as aerobic endurance and muscle strength, can be observed in elite alpine skiers, and that in-season fitness training programmes should take account of this.  相似文献   

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This review focuses on strategic aspects that may affect performance in a long-duration Olympic event, the Olympic distance triathlon. Given the variety of races during the Olympic Games triathlon, strategic aspects include improving technological features as well as energetics factors affecting overall triathlon performance. During the last decade, many studies have attempted to identify factors reducing the metabolic load associated (or not) with the development of fatigue process by analysing the relationship between metabolic and biomechanical factors with exercise duration. To date, a consensus exists about the benefit of adopting a drafting position during the swimming or the cycling part of the triathlon. Other potential strategic factors, such as the production of power output or the selection of cadence during the cycling or the running leg, are likely to affect the overall triathlon performance. Within this approach, pacing strategies are observed by elite athletes who swim or cycle in a sheltered position, inducing several changes of pace, intensity or stochastic shifts in the amplitude of the physiological responses. The analysis of these parameters appears to arouse some experimental and practical interest from researchers and coachers, especially for long-distance Olympic events.  相似文献   

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The purpose of this study was to examine nutritional and supplemental habits among international alpine- and cross-country skiers and power sport athletes in Norway. Data from all the athletes of the National alpine skiing team (ALP: n = 33, 19 men and 14 women) and the National cross-country skiing team (CRO: n = 34, 17 men and 17 women) plus a mixed group of power sport athletes (POW: n = 33, all men) from the National Feanis of boxers, weightlifters and track and field athletes, were collected through a semi-structured interview during their annual medical examination. Twenty percent of all the athletes reported unsatisfactory nutritional habits (CRO 6%, ALP 27% and POW 27%: CRO vs. ALP/POW P <0.05). Eighty-four percent used one or more micronutrient supplement (ALP 70%, POW 88%, CRO 95%: ALP vs. CRO/POW P <0.01). Power sport athletes had the most frequent use of supplemental creatine (45%), proteins/amino acids (30%), vitamins (88%) and minerals (82%), and CRO had the most frequent intake of iron (94%), vitamin C (88%) and fish oils (91%). Among ALP, only 7%, of the female athletes supplemented iron regularly compared to 37% of male ALP ( P <0.05) Overall, male athletes supplemented mostly on a regular basis and female athletes more on an occasional basis. The results show that in spite of differences between sport groups, many elite athletes report unsatisfactory nutritional habits. Micronutrient supplementation was prevalent, but varied between both groups of sports and gender.  相似文献   

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The purpose of this study was to investigate possible factors which may account for differences in performance times within a closely-matched group (in terms of performance) of elite distance runners. The runners were training for competition in the 1984 Olympic Games in either the 5000 m or the 3000 m steeplechase events. Each runner's best performance time (BPT) was obtained and a stepwise regression analysis was performed with the following independent variables: age, weight, % body fat, VO2 max, aerobic threshold (AerT), and anaerobic threshold (AnT). For the 5000 m-runners, a multiple correlation of age and AnT accounted for 77% of the variance (p less than 0.02); for the 3000 m steeplechase runners, body weight alone and body weight and AnT accounted for 94% (p less than .01) and 98% (p less than .05) of the variance, respectively. The results suggest that, among elite middle-distance runners, these parameters deserve attention as potential predictors of performance.  相似文献   

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This review focuses on the most important physical and physiological characteristics of karate athletes from the available scientific research. It has been established that karate's top-level performers require a high fitness level. Top-level male karate athletes are typified by low body fat and mesomorphic-ectomorphic somatotype characteristics. Studies dealing with body composition and somatotype of females are scarce. Aerobic capacity has been reported to play a major role in karate performance. It prevents fatigue during training and ensures the recovery processes during rest periods between two subsequent bouts of fighting activity within a fight and between two consecutive matches. It has been established that there is no significant difference between male and female kata (forms) and kumite (sparring/combat) athletes with regard to aerobic performance. Nevertheless, further studies are needed to support these findings. Concerning anaerobic performance, there is a difference in maximal power explored by the force-velocity test between national and international level karatekas (karate practitioners) but, for the maximum accumulated oxygen deficit test there is no difference between them. Muscle explosive power plays a vital role in a karateka's capacity for high-level performance. However, it has been revealed that vertical jump performance, maximal power and maximal velocity differed between national- and international-level karatekas. Moreover, it has been reported that karate performance relies more on muscle power at lower loads rather than higher ones. Thus, karate's decisive actions are essentially dependent on muscle explosive power in both the upper and lower limbs. With regard to dynamic strength, limited research has been conducted. The maximal absolute bench press, half-squat one-repetition maximum and performance of isokinetic tasks differed significantly between highly competitive and novice male karatekas. Studies on female karate athletes do not exist. Concerning flexibility, which is important for the execution of high kicks and adequate range of action at high speeds, it has been demonstrated that karate athletes' ranges of bilateral hip and knee flexion are greater compared with non-karate athletes. Finally, reaction time is a crucial element in karate because high-level performance is based essentially on explosive techniques. A significant difference in the choice reaction time between high-level and novice karatekas exists. Further research is needed concerning the physiological characteristics of female karatekas, the differences between kata and kumite athletes and variations based on weight categories.  相似文献   

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BACKGROUND: The purpose of the present study was to examine the importance of the somatometric components of elite male and female volleyball players in relation to their different game roles and levels of performance. METHODS: Two hundred and thirty-four male athletes (aged 24.7+/-4.4 years) and 244 female athletes (aged 23.1+/-4.4 years) from the Italian A1 and A2 volleyball leagues underwent anthropometric measurements during the 1992-1993 and 1993-1994 seasons. Somatotypes were estimated with the Heath-Carter method. RESULTS: Marked sexual dimorphism in somatotype was observed in the total sample. The average somatotype for men was 2.2-4.2-3.2 (SD 0.7-0.9-0.9), and for women it was 3.0-3.3-2.9 (SD 0.8-1.0-0.9). The somatotype was significantly different in players at different levels of performance (A1 vs A2 leagues), as it follows: 2.1-4.1-3.3 (SD 0.6-0.8-0.7) vs 2.3-4.3-3.0 (SD 0.7-1.0-0.8) in males; 2.9-3.1-3.0 (SD 0.8-1.0-0.9) vs 3.1-3.5-2.7 (SD 0.8-0.9-0.8) in females. The somatotype was also significantly different in players in different roles. In male sex the mean somatotypes for setters were 2.4-4.5-2.8 (SD 0.7-0.9-0.8), for centres they were 2.0-4.0-3.5 (SD 0.6-1.0-0.8), for spikers they were 2.2-4.3-3.0 (SD 0.6-0.9-0.7), for opposites they were 2.2-4.3-3.1 (SD 0.6-0.9-0.8). In female sex the mean somatotypes for setters were 3.1-3.6-2.5 (SD 0.8-1.0-1.0), for centres they were 2.8-3.1-3.1 (SD 0.8-0.9-0.7), for spikers they were 3.0-3.5-2.8 (SD 0.9-1.0-0.9) and for opposites they were 3.0-3.2-3.0 (SD 0.7-0.9-0.8). CONCLUSIONS: The physique of athletes in the A1 league is characterized by higher ectomorphy and lower endomorphy and mesomorphy. There is also a slight tendency of male players to a greater homogeneity in somatotype within the group at the maximum level of performance. Moreover somatotype differs in relation to game role in volleyball players of both sexes: the mesomorphic component is maximal in setters, while the ectomorphic component is maximal in centres.  相似文献   

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