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1.
In two experiments we examined changes in the perception of action possibilities as a function of exertion. In Experiment 1, participants repeatedly climbed on a climbing wall in a series of trials that progressively increased in number to 10 trials, resulting in increased exertion. Before and during climbing, the participants judged their maximum reaching height and perceived exertion. On a separate day, participants climbed another 10 trials while performing actual maximum reaches. Higher perceived exertion was associated with decreases in perceived maximum reach while the actual reaches did not decrease. However, the perceptual changes occurred early during task execution when the participants were not yet fatigued. When exertion set in, neither perceived nor actual maximum reaching appeared to be affected. In Experiment 2, we included exhaustion trials. The findings replicated the early changes in perception observed in Experiment 1, which may be explained by hands-on experience with the task. Furthermore, while climbing to exhaustion, perceptual judgements largely changed in keeping with changes in the actual maximum reach. Thus, there appeared to be a functional relationship between participants' actual action capabilities, rather than their state of physical fatigue per se, and perceived action possibilities.  相似文献   

2.
Abstract

In two experiments we examined changes in the perception of action possibilities as a function of exertion. In Experiment 1, participants repeatedly climbed on a climbing wall in a series of trials that progressively increased in number to 10 trials, resulting in increased exertion. Before and during climbing, the participants judged their maximum reaching height and perceived exertion. On a separate day, participants climbed another 10 trials while performing actual maximum reaches. Higher perceived exertion was associated with decreases in perceived maximum reach while the actual reaches did not decrease. However, the perceptual changes occurred early during task execution when the participants were not yet fatigued. When exertion set in, neither perceived nor actual maximum reaching appeared to be affected. In Experiment 2, we included exhaustion trials. The findings replicated the early changes in perception observed in Experiment 1, which may be explained by hands-on experience with the task. Furthermore, while climbing to exhaustion, perceptual judgements largely changed in keeping with changes in the actual maximum reach. Thus, there appeared to be a functional relationship between participants' actual action capabilities, rather than their state of physical fatigue per se, and perceived action possibilities.  相似文献   

3.
This paper describes an experiment which examined the effects of anxiety on choice reaction time and movement time. A balanced repeated measures design was adopted in which eight female subjects performed a six‐choice visual reaction task in ‘no anxiety’ and ‘anxiety’ conditions. The anxiety condition required subjects to jump from a balcony 15 feet (4.57 m) into a foam‐filled pit below. Subjects in the anxiety condition demonstrated significantly higher levels of cognitive anxiety and longer reaction times than those in the no anxiety condition. The analysis of the reaction time data also revealed a significant interaction between anxiety and block. No significant effects emerged in the case of movement time.  相似文献   

4.
This paper describes an experiment which examined the effects of anxiety on choice reaction time and movement time. A balanced repeated measures design was adopted in which eight female subjects performed a six-choice visual reaction task in 'no anxiety' and 'anxiety' conditions. The anxiety condition required subjects to jump from a balcony 15 feet (4.57 m) into a foam-filled pit below. Subjects in the anxiety condition demonstrated significantly higher levels of cognitive anxiety and longer reaction times than those in the no anxiety condition. The analysis of the reaction time data also revealed a significant interaction between anxiety and block. No significant effects emerged in the case of movement time.  相似文献   

5.
Climbers often train on indoor climbing walls, which are modifiable to simulate features of outdoor climbing environments at different levels of difficulty. The aim of this study was to evaluate the influence of regularity of climbing holds on emergent perceptual-motor behaviours. Skilled climbers performed six repetitions of two topographically similar routes on an indoor climbing wall. One route was composed of 18 different types of hand holds (irregular route), whereas the other route had only two types of hand holds (regular route). Preview and climbing durations, as well as visual search behaviours, were recorded. Participants rated the regular route as more difficult to climb, requiring greater perceived effort to complete. The time spent previewing, and then climbing the routes, was reduced on average by 12% and 16%, respectively in the irregular route compared to the regular route. There were more fixations made when climbing the regular route (281 vs. 222 fixations per trial). It seems the climbers were more careful and thorough in their gaze behaviours with the regular route because of the additional technical demands it presented, whereas the irregular route afforded a more superficial visual exploration with use of more frequent saccades between holds. The findings suggest how irregularity in the environment is exploited by skilled climbers, apparently making the practice context easier to perceive and act in.  相似文献   

6.
Abstract

Rock climbing is a popular adventure sport with an increasing research base. Early studies in the field did not make comparisons of ascents using different styles of climbing. More recently, differences in the physiological responses for an on-sight lead climb and subsequent lead climb have been reported. The purpose of the present study was to examine the effect of style of climb (lead climb or top rope climb) on the physiological and psychological responses to rock climbing. Nine intermediate climbers volunteered for, and completed, two randomly assigned climbing trials and a maximum oxygen uptake (VO2max) test on a separate occasion. The climbers ascended the same 6a (sport grade) climb for both trials. Before climbing, heart rate, perception of anxiety (Revised Competitive State Anxiety Inventory-2), and blood lactate concentration were measured. Climb time, heart rate, VO2, lactate concentrations, and task load (National Aeronautics and Space Administration Task Load Index) in response to each trial were also recorded. Results indicated significant differences (P<0.05) between the trials for climb time, blood lactate concentration immediately after and 15 min after climbing, and heart rate 1 min after climbing. During lead and top rope climbing, mean VO2 and represented 44% and 42% of treadmill VO2max and mean heart rate represented 81% and 77% of maximum heart rate, respectively. There were no significant differences in feelings of anxiety before either climb, although climbers reported the lead climb to be physically and mentally more demanding, requiring more effort and resulting in greater frustration (P<0.05) than the top rope climb. Our results indicate that the physiological and psychological responses of intermediate climbers are different for a lead climb and top rope climb.  相似文献   

7.
We investigated changes in movement kinematics and attentional focus when expert and novice golfers performed a golf-putting task under pressure. Six male professional golfers and five male novice golfers performed 100 acquisition trials, followed by 10 trials in the pressure condition with a performance-contingent cash reward and small audience. After the 10 trials in the pressure condition, participants answered a questionnaire concerning attentional focus during both types of trial, including such aspects as conscious control of movements and the effects of distraction. A pressure manipulation check revealed a modest increase in physiological arousal, in that heart rate increased by about 10 bpm although state anxiety did not increase. A two-dimensional analysis of movement kinematics revealed that the amplitudes of arm and club movements decreased on the backswing in the pressure condition. Arm and club movement speed decreased on the foreswing in both experts and novices. Furthermore, neither experts nor novices changed their attentional focus in the pressure condition. Whereas previous studies of "choking under pressure" focused on attentional changes, the kinematic changes found in the present study were possibly caused by the influences of strategy modification and/or emotional response. Choking phenomena can be explained by attentional changes, along with the influences of strategy modification and/or emotional response under pressure.  相似文献   

8.
目的:研究负重爬梯训练对大鼠腓肠肌IGF-I,IGF-I Ea,MGF和MSTN基因表达的影响。方法:12只8周龄SD雄性大鼠随机分为实验组(TG,training group)和对照组(CG,control group)。TG组采用尾部负重(负荷从体重的30%逐周增加至200%)爬梯训练模式,训练10周(3times/set,2sets/day,3days/week),采用免疫组化和RT-PCR方法分析大鼠腓肠肌IGF-I多肽、IGF-I Ea、MGF和MSTNmRNA基因表达。结果:10周训练后,相对CG组,IGF-I多肽和MGF mRNA在TG组腓肠肌的表达量上调(P<0.05),IGF-I Ea mRNA的表达量没有变化(P>0.05),MSTN mRNA的表达量下调(P<0.05)。结论:负重爬梯抗阻训练可以通过上调IGF-I多肽、MGF mRNA和下调MSTN mRNA引起大鼠腓肠肌肌肉肥大,IGF-IEa mRNA对这一过程可能没有影响。  相似文献   

9.
运动焦虑的产生及其与运动成绩的关系   总被引：1，自引：0，他引：1  
本文阐述了焦虑与运动成绩关系的理论假说,分析运动员焦虑产生的原因与特点,从而通过问卷或量表评估、生理变化评估以及行为表现评估对运动员的运动焦虑进行恰当的评价,以此在赛前、赛中及赛后对运动员的焦虑进行调节,使其焦虑水平达到最佳的水平。  相似文献   

10.
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11.
The aim of this study was to analyse the effect of stimulus change timing on reaction response time parameters, horizontal velocity of the centre of mass (CM) and precision during offensive actions in fencing. Twelve fencers from the Spanish National Foil Team were included in the study. Two 500 Hz force plates were used to register the horizontal component of the reaction force while a 3D video camera set at 250 Hz recorded the spatial position of 11 body markers and a projector connected to a programmed stopwatch projected a moving target (stimulus) on a screen. When the circle (target) appeared in the centre of the plastron, fencers had to execute a step-forward-lunge as fast as possible, trying to touch the circle with the tip of the foil. During the lunge, the position of the target could randomly shift or not to three different positions. The stimulus change was performed randomly at four different times with a progressive delay. The results show that target changes did not have any effect when they occurred at the beginning of the movement sequence. However, when the target change was delayed, reaction and movement times increased and the technical execution of the lunge changed, leading to more errors.  相似文献   

12.
State anxiety is known to affect far aiming tasks, but less is known about the effects of state anxiety on running and aiming while running. Therefore, in the current study participants ran on a treadmill at their preferred speed in a low- and high-anxiety condition. In both conditions, running was combined with dart throwing in the last minutes. Results showed that attention shifted away from task execution with elevated levels of anxiety. Furthermore, gait patterns were more conservative and oxygen uptake was higher with anxiety. In addition, performance and efficiency on the dart throwing task also decreased with anxiety. These findings are in line with attentional control theory and provide an indication that state anxiety not only affects aiming tasks but also tasks that rely heavily on the aerobic system. Moreover, findings indicate that when combined, running, aiming, and anxiety all compete for attention leading to suboptimal attentional control and possibly a decrease in performance.  相似文献   

13.
The aim of the study was to quantify the activation of arm and shoulder muscles during a static therapeutic climbing exercise and to investigate the possibility of altering the muscle activation through arm position (Jug, Undercling, Sidepull internal rotated, Sidepull external rotated), hand support (one-handed, double-handed) and wall inclination (0°, 12°). Electromyographic (EMG) activity of 14 healthy, climbing unexperienced males for the right m. biceps brachii (BB), m. serratus anterior (SA), m. upper, middle and lower trapezius (UT, MT, LT) showed mainly low to moderate EMG activation levels (BB: 4.1–40.1% maximum voluntary isometric contraction (MVIC), SA: 4.5–24.5% MVIC, UT: 1.3–28.0% MVIC, MT: 8.6–47.1% MVIC, LT: 3.8–47.3% MVIC). Significant differences occurred between the four arm positions for the UT and LT. The one-handed support revealed significant higher muscle activation than the double-handed support in every condition except for SA in Undercling arm position at 12° wall inclination. Increasing the wall inclination (from 0° to 12° overhang) led to a significant increase in muscle activation in nearly every exercise variation and muscle. These findings suggest that arm position, hand support and wall inclination are appropriate possibilities of altering muscle activation patterns in therapeutic climbing.  相似文献   

14.
Abstract

Indices of red blood cell (RBC) status were assessed in eight high school women cross-country runners (experimental group) six times during a competitive season (Weeks 0, 1, 2, 4, 6, and 8) and three times (Weeks 0, 1, and 3) in 11 high school women who were not runners (comparison group). The only significant preseason hematological difference between the groups was a higher RBC fragility for the runners. All blood indices for both groups were within normal ranges throughout the study. During the competitive season (Weeks 0–8), the runners had a significant increase in [Vdot]O2 max (ml/kg · min?1) of 7.6% and a significant decrease in post step-test heart rate (13.4%) but showed no changes in body weight, height, or percent body fat. At Week 3, the comparison group showed an increase (0.9%) in body weight, but no changes were observed in the other anthropometric variables or post step-test heart rate. During the competitive season, the runners had significant changes in all blood variables except reticulocyte count; these changes were most marked during the first week of the season when there were significant decreases in hemoglobin (Hb) concentration (8.0%), hematocrit (Hct) (7.7%), RBC count (6.8%), and osmotic fragility (21.5% and 42.0% in 5.95 and 6.80 mM NaCl solutions, respectively) and a significant increase in mean RBC volume (1.8%). In contrast, the only significant change in blood indices of the comparison group was a decrease (1.9%) in mean RBC volume at the end of Week 1. Changes in blood variables of the runners appeared to be transient, in that values at Week 8 were comparable to those at preseason except for mean RBC volume. Although blood volume changes could be responsible for some of the blood variable changes in the runners, the results support increased RBC destruction rather than hemodilution as a cause of the RBC changes in the runners, and suggest a possible stress on body iron reserves for increased erythropoiesis during recovery from those changes.  相似文献   

15.
In this study, we compared the effects of a 72-h exercise abstinence period and normal exercise on the affect and body dissatisfaction of 58 healthy women (mean age 26.1 years, s = 8.2) who exercised at least four times per week, and explored the relationship between the changes in affect and body dissatisfaction. Participants completed the UWIST-MACL and Body Dissatisfaction Scale to assess affect and body image, and were randomized to an abstinence or control group. Affect and body image for both groups were re-assessed following the 72-h abstinence period. Compared with the control group, the abstinence group had a significant decrease in hedonic tone and energetic arousal, and a significant increase in tense arousal and body dissatisfaction from pre-intervention to post-intervention. There were no significant relationships between the changes in body dissatisfaction and the components of affect. A 72-h exercise abstinence period resulted in increased affect disturbance and body dissatisfaction in regularly active women.  相似文献   

16.
The aim of this study was to examine retrospective perceptions and causal beliefs about temporal experiences of competitive anxiety and related symptoms in the lead up to competition. Qualitative interviews were conducted with 9 elite performers to examine the interaction of intensity, frequency and direction of symptoms associated with competitive anxiety before competition. Data analysis identified six causal networks that supported theoretical predictions suggesting that intensity of cognitive anxiety symptoms remained relatively stable in the lead up to competition, whereas somatic anxiety peaked sharply at the onset of performance. Frequency of anxiety symptoms increased as the competition approached and changes in interpretation of anxiety symptoms were also reported, with self-confidence identified as a moderating variable. The findings highlight the dynamic properties of the stress response and emphasize the need to consider the idiosyncratic nature of the level, frequency and interpretation of performers' precompetitive experiences.  相似文献   

17.
The aim of this study was to examine retrospective perceptions and causal beliefs about temporal experiences of competitive anxiety and related symptoms in the lead up to competition. Qualitative interviews were conducted with 9 elite performers to examine the interaction of intensity, frequency and direction of symptoms associated with competitive anxiety before competition. Data analysis identified six causal networks that supported theoretical predictions suggesting that intensity of cognitive anxiety symptoms remained relatively stable in the lead up to competition, whereas somatic anxiety peaked sharply at the onset of performance. Frequency of anxiety symptoms increased as the competition approached and changes in interpretation of anxiety symptoms were also reported, with self-confidence identified as a moderating variable. The findings highlight the dynamic properties of the stress response and emphasize the need to consider the idiosyncratic nature of the level, frequency and interpretation of performers' precompetitive experiences.  相似文献   

18.
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19.
从登山运动中衍生而来的攀岩运动,是我国政府2013年公布的首批4项高危险性体育项目之一,其损伤风险日益受到关注。为揭示攀岩运动损伤的流行病学特征,综述了国内外攀岩运动损伤相关文献,对攀岩运动损伤发生率、损伤特征和影响因素进行了梳理。结果表明,室内人工岩壁攀登的损伤发生率总体上处于较低水平;损伤多发生在手、肩、肘、腕、膝、踝等部位,但攀爬方式的转变引起了损伤部位的明显变化,当前手指滑车、手掌和肩关节损伤最为常见;损伤类型中较多为过度使用损伤和急性损伤,过度使用损伤多发于上肢,急性损伤多发于下肢;损伤的程度一般较轻。攀岩运动员的年龄、性别、运动水平、运动负荷等自身因素以及场地、保护员水平、装备器材等外部因素均会对损伤特征产生影响。建议进一步探讨攀岩运动的损伤机制和预防措施,并统一攀岩运动损伤的定义和统计标准,针对不同人群进行长期的跟踪研究,以加深对攀岩运动损伤特征和机制的认识,帮助攀岩教练员与运动员更好地预防损伤的发生。  相似文献   

20.
Abstract

In this study, we compared the effects of a 72-h exercise abstinence period and normal exercise on the affect and body dissatisfaction of 58 healthy women (mean age 26.1 years, s = 8.2) who exercised at least four times per week, and explored the relationship between the changes in affect and body dissatisfaction. Participants completed the UWIST-MACL and Body Dissatisfaction Scale to assess affect and body image, and were randomized to an abstinence or control group. Affect and body image for both groups were re-assessed following the 72-h abstinence period. Compared with the control group, the abstinence group had a significant decrease in hedonic tone and energetic arousal, and a significant increase in tense arousal and body dissatisfaction from pre-intervention to post-intervention. There were no significant relationships between the changes in body dissatisfaction and the components of affect. A 72-h exercise abstinence period resulted in increased affect disturbance and body dissatisfaction in regularly active women.  相似文献   

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