Sport imagery ability predicts trait confidence,and challenge and threat appraisal tendencies

Abstract

The present study investigated the interplay among athletes' sport imagery ability, trait confidence, and tendency to appraise situations as a challenge and threat. The potential mediating role of trait confidence was also tested. A total of 207 athletes (M _age =19.44; s=1.26; 90 female, 117 male) completed the Sport Imagery Ability Questionnaire to assess ease of imaging skill, strategy, goal, affect and mastery imagery, the confidence subscale of the Competitive Trait Anxiety Inventory to measure trait confidence, and the Cognitive Appraisal Scale to assess tendencies to appraise sport situations as a challenge and as a threat. Structural equation modelling supported a model wherein mastery and goal imagery ability both positively predicted confidence, which in sequence positively predicted challenge appraisal and negatively predicted threat appraisal tendency. Partial support was found for confidence mediating the relationship between mastery imagery ability and appraisal tendencies. In addition, ease of imaging mastery and affect imagery directly predicted challenge appraisal tendency (positive direction), and ease of imaging mastery imagery directly predicted threat appraisal tendency (negative direction). Results highlight the importance of motivational imagery ability and the need to assess athletes' ability to image different content.     

Effect of 6 weeks of endurance training on the lactate minimum speed

The aim of this study was to assess the sensitivity of the lactate minimum speed test to changes in endurance fitness resulting from a 6 week training intervention. Sixteen participants (mean +/- s: age 23+/-4 years; body mass 69.7+/-9.1 kg) completed 6 weeks of endurance training. Another eight participants (age 23+/-4 years; body mass 72.7+/-12.5 kg) acted as non-training controls. Before and after the training intervention, all participants completed: (1) a standard multi-stage treadmill test for the assessment of VO2max, running speed at the lactate threshold and running speed at a reference blood lactate concentration of 3 mmol x l(-1); and (2) the lactate minimum speed test, which involved two supramaximal exercise bouts and an 8 min walking recovery period to increase blood lactate concentration before the completion of an incremental treadmill test. Additionally, a subgroup of eight participants from the training intervention completed a series of constant-speed runs for determination of running speed at the maximal lactate steady state. The test protocols were identical before and after the 6 week intervention. The control group showed no significant changes in VO2max, running speed at the lactate threshold, running speed at a blood lactate concentration of 3 mmol x l(-1) or the lactate minimum speed. In the training group, there was a significant increase in VO2max (from 47.9+/-8.4 to 52.2+/-2.7 ml x kg(-1) x min(-1)), running speed at the maximal lactate steady state (from 13.3+/-1.7 to 13.9+/-1.6 km x h(-1)), running speed at the lactate threshold (from 11.2+/-1.8 to 11.9+/-1.8 km x h(-1)) and running speed at a blood lactate concentration of 3 mmol x l(-1) (from 12.5+/-2.2 to 13.2+/-2.1 km x h(-1)) (all P < 0.05). Despite these clear improvements in aerobic fitness, there was no significant difference in lactate minimum speed after the training intervention (from 11.0+/-0.7 to 10.9+/-1.7 km x h(-1)). The results demonstrate that the lactate minimum speed, when assessed using the same exercise protocol before and after 6 weeks of aerobic exercise training, is not sensitive to changes in endurance capacity.     

Effect of 6 weeks of endurance training on the lactate minimum speed

The aim of this study was to assess the sensitivity of the lactate minimum speed test to changes in endurance fitness resulting from a 6 week training intervention. Sixteen participants (mean +/- s :age 23 +/- 4 years;body mass 69.7 +/- 9.1 kg) completed 6 weeks of endurance training. Another eight participants (age 23 +/- 4 years; body mass 72.7 +/-12.5 kg) acted as non-training controls. Before and after the training intervention, all participants completed: (1) a standard multi-stage treadmill test for the assessment of VO 2max , running speed at the lactate threshold and running speed at a reference blood lactate concentration of 3 mmol.l -1 ; and (2) the lactate minimum speed test, which involved two supramaximal exercise bouts and an 8 min walking recovery period to increase blood lactate concentration before the completion of an incremental treadmill test. Additionally, a subgroup of eight participants from the training intervention completed a series of constant-speed runs for determination of running speed at the maximal lactate steady state. The test protocols were identical before and after the 6 week intervention. The control group showed no significant changes in VO 2max , running speed at the lactate threshold, running speed at a blood lactate concentration of 3 mmol.l -1 or the lactate minimum speed.In the training group, there was a significant increase in VO 2max (from 47.9 +/- 8.4 to 52.2 +/- 2.7 ml.kg -1 .min -1 ), running speed at the maximal lactate steady state (from 13.3 +/- 1.7 to 13.9 +/- 1.6 km.h -1 ), running speed at the lactate threshold (from 11.2 +/- 1.8 to 11.9 +/- 1.8 km.h -1 ) and running speed at a blood lactate concentration of 3 mmol.l -1 (from 12.5 +/- 2.2 to 13.2 +/- 2.1 km.h -1 ) (all P ? 0.05). Despite these clear improvements in aerobic fitness, there was no significant difference in lactate minimum speed after the training intervention (from 11.0 +/- 0.7 to 10.9 +/- 1.7 km.h -1 ). The results demonstrate that the lactate minimum speed,when assessed using the same exercise protocol before and after 6 weeks of aerobic exercise training, is not sensitive to changes in endurance capacity.     

Pre-competition imagery,self-efficacy and performance in collegiate golfers

In this study, we examined the relationships between self-efficacy, pre-competition imagery use and performance. A modified version of the Sport Imagery Questionnaire was used to assess both the motivational and cognitive functions of imagery used by 51 varsity golfers during the hour before a Provincial University Golf Championship. In line with Martin and co-workers' model of imagery use in sport, we hypothesized that self-efficacy would be positively related to motivational general-mastery imagery use and motivational generalmastery imagery use would be predictive of golf performance. Also, consistent with theorizing by Bandura, we hypothesized that self-efficacy would predict golf performance, but that the relationship between self-efficacy and performance would be mediated by imagery use. The results of hierarchical multiple regression analyses revealed that pre-competition motivational general-mastery imagery accounted for significant variance in both self-efficacy (adjusted R 2 = 0.26, P ? 0.01) and performance (adjusted R 2 = 0.31, P ? 0.01). The results also indicated that self-efficacy was predictive of golf performance and that motivational general-mastery imagery use mediated the relationship between self-efficacy and performance. The results are discussed in relation to athletes' pre-competition preparation and intervention.     

Pre-competition imagery,self-efficacy and performance in collegiate golfers

In this study, we examined the relationships between self-efficacy, pre-competition imagery use and performance. A modified version of the Sport Imagery Questionnaire was used to assess both the motivational and cognitive functions of imagery used by 51 varsity golfers during the hour before a Provincial University Golf Championship. In line with Martin and co-workers' model of imagery use in sport, we hypothesized that self-efficacy would be positively related to motivational general-mastery imagery use and motivational general-mastery imagery use would be predictive of golf performance. Also, consistent with theorizing by Bandura, we hypothesized that self-efficacy would predict golf performance, but that the relationship between self-efficacy and performance would be mediated by imagery use. The results of hierarchical multiple regression analyses revealed that pre-competition motivational general-mastery imagery accounted for significant variance in both self-efficacy (adjusted R2 = 0.26, P < 0.01) and performance (adjusted R2 = 0.31, P < 0.01). The results also indicated that self-efficacy was predictive of golf performance and that motivational general-mastery imagery use mediated the relationship between self-efficacy and performance. The results are discussed in relation to athletes' pre-competition preparation and intervention.     

中老年2型糖尿病有氧运动干预的Meta分析

目的:检验间歇和持续有氧运动对中老年2型糖尿病患者的干预效果,从而提供较为科学合理的运动处方。方法:通过Web of science、PubMed/MEDLINE、Cochrane Library、EMBASE、SportDiscus、中国知网(CNKI)、万方等中外文数据库,检索有关间歇与持续有氧运动干预中老年2型糖尿病患者的随机对照试验研究,利用Review Manager 5.3统计软件进行计量分析,包括偏倚风险评估、异质性分析、合并效应与效应大小检验和敏感性分析。结果:1)共纳入9项研究,包括297名被试;2)间歇训练与持续训练能有效改善中老年2型糖尿病患者胰岛素抵抗、BMI、有氧适能和疲劳、幸福感等身心健康指标;3)两者在改善HbA1c%(P=0.04)、总胆固醇(P=0.00)、收缩压(P=0.00)和有氧适能(P=0.00)方面存在显著差异;4)15~30 min/次、3~5次/周,持续8~12周的中至高等强度间歇训练对糖化血红蛋白、收缩压和有氧适能的干预效应更优,而长于12周、5次/周、大于30 min/次的中等强度间歇训练对总胆固醇可以产生较好的干预效应。结论:间歇训练与持续训练能一定程度改善中老年2型糖尿病患者的身心健康,相较于持续训练,间歇训练能更有效降低HbA1c%、总胆固醇、收缩压、提高有氧适能,15~30 min/次、3~5次/周、持续8~12周的中等强度间歇训练是干预中老年2型糖尿病较为有效的运动处方。     

Movement and stretching imagery during flexibility training

The aim of this study was to examine the effect of movement and stretching imagery on increases in flexibility. Thirty volunteers took part in a 4 week flexibility training programme. They were randomly assigned to one of three groups: (1) movement imagery, where participants imagined moving the limb they were stretching; (2) stretching imagery, where participants imagined the physiological processes involved in stretching the muscle; and (3) control, where participants did not engage in mental imagery. Active and passive range of motion around the hip was assessed before and after the programme. Participants provided specific ratings of vividness and comfort throughout the programme. Results showed significant increases in flexibility over time, but no differences between the three groups. A significant relationship was found, however, between improved flexibility and vividness ratings in the movement imagery group. Furthermore, both imagery groups scored significantly higher than the control group on levels of comfort, with the movement imagery group also scoring significantly higher than the stretching imagery group. We conclude that the imagery had stronger psychological than physiological effects, but that there is potential for enhancing physiological effects by maximizing imagery vividness, particularly for movement imagery.     

Movement and stretching imagery during flexibility training

Abstract

The aim of this study was to examine the effect of movement and stretching imagery on increases in flexibility. Thirty volunteers took part in a 4 week flexibility training programme. They were randomly assigned to one of three groups: (1) movement imagery, where participants imagined moving the limb they were stretching; (2) stretching imagery, where participants imagined the physiological processes involved in stretching the muscle; and (3) control, where participants did not engage in mental imagery. Active and passive range of motion around the hip was assessed before and after the programme. Participants provided specific ratings of vividness and comfort throughout the programme. Results showed significant increases in flexibility over time, but no differences between the three groups. A significant relationship was found, however, between improved flexibility and vividness ratings in the movement imagery group. Furthermore, both imagery groups scored significantly higher than the control group on levels of comfort, with the movement imagery group also scoring significantly higher than the stretching imagery group. We conclude that the imagery had stronger psychological than physiological effects, but that there is potential for enhancing physiological effects by maximizing imagery vividness, particularly for movement imagery.     

低氧训练对肥胖大鼠糖有氧代谢关键酶基因表达的影响

目的:通过建立肥胖大鼠低氧训练模型,观察比目鱼肌糖有氧代谢关键酶的基因表达水平,探讨低氧训练对肥胖大鼠有氧代谢能力的影响。方法:出生21天的离乳雄性SD大鼠,经高脂饲料喂养10周、肥胖模型验证成功后,继续高脂饲料喂养2周,筛选130只随机分为13组:对照0周组,低氧安静1、2、3、4周组,常氧训练1、2、3、4周组,低氧训练1、2、3、4周组。低氧环境模拟海拔3 500m(氧浓度13.6%);常氧和低氧训练组分别以25m/min、20m/min进行跑台训练,各训练组持续运动1h/d、6d/w、1～4w。采用荧光定量PCR法测试比目鱼肌组织CS-2、NAD+-IDH3α、DLST-2mRNA表达水平。结果:1)常氧训练组第1、3周CS-2mRNA相对表达量较第2周显著升高(P<0.05),低氧安静组第3周较第1周显著降低(P<0.05)。第3周时低氧安静组、低氧训练组较常氧训练组显著降低(P<0.01或P<0.05)。2)常氧训练组、低氧安静组第2、3、4周NAD+-IDH3αmRNA相对表达量较0周显著升高(P<0.01或P<0.05),低氧训练组第1、2、4周较0周显著升高(P<0.05或P<0.01)。第1周时低氧安静组、低氧训练组较常氧训练组显著升高(P<0.01);第4周时低氧训练组较常氧训练组、低氧安静组显著升高(P<0.05或P<0.01)。3)常氧训练组第2、3、4周DLST-2mRNA相对表达量较0、1周显著降低(P<0.05或P<0.01),低氧安静组、低氧训练组第1、2、3、4周较0周显著降低(P<0.01);第1、3周时低氧安静组、低氧训练组较常氧训练组显著下降(P<0.05或P<0.01);第2周时低氧训练组较常氧训练组显著升高(P<0.05)。结论:1)4周低氧训练可逆转肥胖大鼠比目鱼肌由于低氧导致的CS-2mRNA表达的下降,以提高机体的有氧代谢能力。2)4周低氧训练上调肥胖大鼠比目鱼肌NAD+-IDH3αmRNA表达的作用强于常氧训练和低氧安静,可在一定程度上提高机体的有氧代谢能力。3)4周低氧训练、常氧训练和低氧安静均下调肥胖大鼠比目鱼肌DLST-2mRNA表达,可能在一定程度上影响机体的有氧代谢能力。     

Progressive velocity throwing training increases velocity without detriment to accuracy in sub-elite cricket players: A randomized controlled trial

Abstract

Throwing performance is vital within the sport of cricket. However, little published evidence exists regarding methods to improve throwing velocity and/or accuracy in any cricket-playing population. This study, therefore, assessed the efficacy of progressive velocity throwing training on throwing velocity and accuracy in a cricket-specific test. Eighteen sub-elite male cricket players were assessed for maximal throwing velocity and throwing accuracy at four different throwing velocities relative to maximal throwing velocity. The participants were randomly assigned to either an intervention (n=9) or control (n=9) group. Both groups performed usual pre-season activities for 8 weeks, during which the intervention group performed two additional specific throwing training sessions per week. Maximal throwing velocity was re-assessed at 4 weeks and the progressive velocity throwing programme was adjusted accordingly. The 8-week progressive velocity throwing training significantly increased peak and mean maximal throwing velocity (P = 0.01). Absolute changes in peak and mean maximal throwing velocity were negatively and significantly correlated with initial maximal throwing velocity at 4 weeks (r=?0.805, P = 0.01 and r=?0.806, P = 0.01 respectively) but not at 8 weeks. No significant difference was observed in accuracy for either group at any time. This is the first published study to describe the effectiveness of a progressive velocity throwing training programme on throwing performance in a group of sub-elite cricket players. The addition of two specific throwing training sessions per week can increase maximal throwing velocity without detriment to throwing accuracy.     

The effects of two different correction strategies on the snatch technique in weightlifting

Improving motor skills represents one of the major issues in motor control and motor learning literature. The aim of this study was to investigate which of two strategies, method of amplification of error (MAE) or direct instruction (DI), would be more beneficial for error correction of the snatch technique. Thirty well-trained male weightlifters were randomly assigned to one of three training conditions (MAE, DI and Control). The experiment took place in only one practice session in which each lifter performed 3 pretraining trials, 8 training intervention trials, and 3 post-training trials, and a retention test session after 1 week. An optoelectronic motion capture system was used to measure the kinematic parameters of the weightlifting performance. After the training intervention, data showed that the MAE group revealed a greater improvement in several kinematic parameters when compared to the DI and Control groups, and the benefits derived from its application were still present 1 week later in the retention test. Nevertheless, the findings of the present study should be interpreted with caution due to the relatively small sample size; further research will also be necessary to evaluate the effects of MAE with different ability levels and other sport skills. The present findings could have practical implications for sport psychology and physical education because while practice is obviously necessary for improving learning, the efficacy of the learning process is essential in enhancing learners’ motivation and sport enjoyment.     

Effect of intermittent normobaric hypoxic exposure at rest on haematological, physiological, and performance parameters in multi-sport athletes

The aim of this study was to determine whether 3 weeks of intermittent normobaric hypoxic exposure at rest was able to elicit changes that would benefit multi-sport athletes. Twenty-two multi-sport athletes of mixed ability were exposed to either a normobaric hypoxic gas (intermittent hypoxic training group) or a placebo gas containing normal room air (placebo group). The participants breathed the gas mixtures in 5-min intervals interspersed with 5-min recovery periods of normal room air for a total of 90 min per day, 5 days per week, over a 3-week period. The oxygen in the hypoxic gas decreased from 13% in week 1 to 10% by week 3. The training and placebo groups underwent a total of four performance tests, including a familiarization and baseline trial before the intervention, followed by trials at 2 and 17 days after the intervention. Time to complete the 3-km run decreased by 1.7%[95% confidence interval (CI) = -0.6 - 3.9%] 2 days after, and by 2.3% (CI = 0.25 - 4.4%) 17 days after, the last hypoxic episode in the training relative to the placebo group. Substantial changes in the training relative to the placebo group also included increased reticulocyte count 2 days (23.5%; CI =-1.9 to 44.9%) and 12 days (14.6%; CI = -7.1 to 36.4%) post-exposure. The effect of intermittent hypoxic training on 3-km performance found in this study is likely to be beneficial, which suggests non-elite multi-sport athletes should expect such training to enhance performance.     

太极拳和快走练习对老年女性平衡能力的影响

目的:探索太极拳练习和快走练习对老年人平衡能力的影响效果。方法:31名老年女性被随机分成太极拳组(TC)和快走组(BW)。两组受试者分别接受16周的太极拳练习和快走练习,每周5次,每次1h,随后停止练习跟踪8周。受试者每4周测试一次平衡能力,共测试7次。测试指标包括睁眼(SLO)和闭眼(SLC)状态下的单腿站立时间(TIME)、足底压力中心在左右方向的最大位移量(DX)、足底压力中心在前后方向的最大位移量(DY)。结果:太极拳组(TC)TIME-SLO/SLC从第4周显著性增加,而快走组(BW)从第8周显著性增加;太极拳组DX-SLO/SLC、DY-SLO/SLC从第8周显著性减少,而快走组从第12周显著减少。停练阶段,太极组的平衡能力指标未有显著性变化,但快走组指标中除了DY,其他指标均有明显变化的趋势。结论:太极拳和快走练习均可以提高老年人的平衡能力,太极拳提高的更快(太极vs.快走:8周vs.12周);8周的停练阶段,两种练习方式对平衡能力均有较好的维持作用,但太极拳的维持效果更好。因此,相比于快走练习,老年人可以考虑将太极拳作为首选的练习方式。     

有氧运动与抗阻运动对非酒精性脂肪肝病疗效差异的Meta分析

目的:探索有氧运动和抗阻运动两种常见运动方式对非酒精性脂肪肝病(NAFLD)患者内脏脂肪、肝功能与脂代谢治疗效果对比,为患者选择适宜的运动方案提供依据。方法:检索PubMed、Web of Science、中国知网等数据库,搜集随机对照试验文献,采用Cochrane偏倚风险评估文献质量,Review Manager 5.3软件meta分析。结果:1)内脏脂肪与脂代谢方面,有氧运动与抗阻运动之间的疗效差异不具有统计学意义;2)肝功能方面,肝功能天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)与氨酰转移酶(GGT)在两种运动间的疗效差异不具有统计学意义;进一步亚组分析显示,有氧运动对AST在“年龄<52岁”、“BMI≥28”、“干预频次为3次/周”、“干预周期≤12周”亚组中改善效果比抗阻运动好;对ALT的改善在“BMI≥28”、“干预频次为3次/周”亚组中效果更佳。结论:有氧运动与抗阻运动相比,对NAFLD患者内脏脂肪、肝功能与脂代谢治疗效果均无差异,两种运动方式的干预效果相近;但不同亚组仍表现出差异,有氧运动组AST在低龄、高BMI、短干预周期和短干预频次组改善效果更佳,ALT在低龄、短干预周期组具有更好效果。提示患者应根据自身心肺功能、肌肉力量及自身运动情况等,选择适宜自己的运动进行,而当患者需要改善AST与ALT时,建议选择有氧运动干预方式。     

体育院校女大学生核心区等长收缩肌力追踪实验研究

目的：通过对体育院校女大学生进行核心力量训练干预后的追踪测试与效果评价的实验研究,了解其核心力量变化的特点、规律,探寻稳定与非稳定对核心力量及平衡能力的影响。方法：选取成都体育学院2011级平均年龄为20岁,参与体育锻炼年限为5±1年的女大学生45名,随机分为A、B、C三组,除均参加正常术科课锻炼外,A、B两组还要分别参加为期8周,每周3次,每次1h的非稳定与稳定核心力量训练的干预,C组为对照组不进行核心力量训练干预。8周训练干预结束后,三组均继续参加正常术科课的锻炼。本实验采用＂智能核心肌力诊疗系统＂等多种仪器,进行5次追踪测试受试者不同阶段核心肌力、人体平衡能力等方面的多项指标。用SPSS16.0软件对测试数据进行处理,并分别进行三组不同阶段数据对比;不同阶段数据变化量组间对比。结果：（1）采用核心力量训练干预的受试者比未干预核心力量训练的对照组在核心区等长肌力有显著性差异;（2）在停止训练后,采用非稳定核心力量训练干预组核心等长肌力的下降趋势相比采用稳定核心力量组及对照组有明显差异。结论与建议：（1）稳定核心力量训练能够在较短的时间内提升核心区等长肌力;（2）非稳定核心力量训练对延缓核心区等长肌力下降有一定帮助;（3）非稳定核心力量训练难度较大,短时间内不能达到提高肌力的效果。建议在体育院校女大学生体能训练中适当增加核心力量训练,尤其是非稳定形式的核心力量训练,以帮助增强核心区力量素质,为今后顺利完成专选课学习奠定良好的身体素质,避免不必要的运动损伤。     

Measurement of motivational imagery abilities in sport

Athletes report using imagery most often to successfully cope with and master challenging situations. This function of imagery is termed "motivational general-mastery" and includes imagining being focused, confident and in control in difficult circumstances. Also, athletes often use imagery to regulate their arousal levels (e.g. relaxing, psyching up) and this function of imagery is termed "motivational-general arousal". While most athletes report employing these two motivational functions of imagery, their ability to do so has not been examined. The aim of the present study was to develop a measure of motivational general sport imagery ability, the Motivational Imagery Ability Measure for Sport (MIAMS). This was accomplished through three phases. Across these phases, evidence was generated showing that the psychometric properties of the instrument are adequate. In addition, the relationship of scores on the MIAMS to demographic variables, including sex, sport type and competitive standard, were examined. It was found that athletes participating at a competitive level scored higher on the MIAMS than athletes participating at a recreational level.     

运动锻炼对产妇抑郁干预效果的Meta分析

运用Meta分析系统评价运动锻炼对产妇产后抑郁的干预效果,探索可能产生较大干预效应的运动方案。结果表明：（1）运动锻炼对产妇抑郁呈大效应量干预效果;（2）运动内容对产妇抑郁的干预效应量依次为有氧运动、组合练习、抗阻练习;（3）单次干预时长对产妇抑郁的干预效应量分别为30~40 min亚组、60 min亚组;（4）4-5次/周的干预频率对产妇抑郁的干预效应量最大,且干预效应随干预频率减少而减少;（5）持续3-4周至24周的运动锻炼均对产后抑郁产生了良好干预效应,12周左右运动锻炼的干预效应最好;（6）练习形式对产妇抑郁的干预效应量依次为集体练习、个人练习。结论：（1）运动锻炼能有效改善产后抑郁症状,产后运动可能优于产前运动干预效果;集体锻炼可能优于个人锻炼干预效果;（2）每周锻炼4-5次、每次锻炼持续30~40 min左右、共持续12周左右的中等强度有氧运动更有可能获得改善产后抑郁的理想干预效果。     

Effect of intermittent normobaric hypoxic exposure at rest on haematological,physiological, and performance parameters in multi-sport athletes

Abstract

The aim of this study was to determine whether 3 weeks of intermittent normobaric hypoxic exposure at rest was able to elicit changes that would benefit multi-sport athletes. Twenty-two multi-sport athletes of mixed ability were exposed to either a normobaric hypoxic gas (intermittent hypoxic training group) or a placebo gas containing normal room air (placebo group). The participants breathed the gas mixtures in 5-min intervals interspersed with 5-min recovery periods of normal room air for a total of 90 min per day, 5 days per week, over a 3-week period. The oxygen in the hypoxic gas decreased from 13% in week 1 to 10% by week 3. The training and placebo groups underwent a total of four performance tests, including a familiarization and baseline trial before the intervention, followed by trials at 2 and 17 days after the intervention. Time to complete the 3-km run decreased by 1.7%[95% confidence interval (CI) = ?0.6 – 3.9%] 2 days after, and by 2.3% (CI = 0.25 ? 4.4%) 17 days after, the last hypoxic episode in the training relative to the placebo group. Substantial changes in the training relative to the placebo group also included increased reticulocyte count 2 days (23.5%; CI =?1.9 to 44.9%) and 12 days (14.6%; CI = ?7.1 to 36.4%) post-exposure. The effect of intermittent hypoxic training on 3-km performance found in this study is likely to be beneficial, which suggests non-elite multi-sport athletes should expect such training to enhance performance.     

大鼠下丘脑SST及垂体SSTR-1对6周递增负荷运动的应答和适应

目的观察递增负荷运动造成免疫功能下降过程中生长抑素(SST)和生长抑素1型受体(SSTR-1)的应答和适应变化特征,探讨其可能机理。方法 120只SD雄性大鼠随机分为试验组和对照组,又依据取样时间的不同分为15小组,建立递增负荷训练模型。分别于第0、2、4、6周末的运动前安静状态、运动后即刻和运动后3 h,将大鼠全身灌流固定后取脑及垂体,冠状位连续石蜡切片后免疫组织化学染色,所得图像使用Image-Pro Plus6.0图像分析软件分析。结果 (1)下丘脑中SST主要分布在3V旁室周核的上半部分,为胞质阳性;SSTR-1主要分布在垂体边缘,为胞膜阳性。(2)各组大鼠下丘脑SST及垂体SSTR-1对6周递增负荷运动的适应性变化特征为:①对照组大鼠SST在6周内无显著性差异,SSTR-1在第2周时最低,依次为第0、4周,至第6周时最高;②2周安静状态SST较0周明显增多,4周安静时下降至略低于0周,第6周则下降更低;SSTR-1安静状态下4周最高,依次为第6、2和0周。(3)各周大鼠下丘脑SST及垂体SSTR-1对1次性运动的应答性变化特征为:①第0、4周运动后即刻SST的表达增多,而第2、6周减少;训练第0、2、4周大鼠运动后3 h均可恢复至运动前安静状态,第6周则不能恢复;②SSTR-1在运动即刻及恢复3 h后的变化规律与SST一致,但运动结束后3 h的恢复程度较SST低,有滞后现象。结论 (1)在长期递增负荷运动影响下,安静状态时大鼠下丘脑SST运动初期一过性增加,之后呈下降趋势,适宜运动可以减少安静状态SST的表达,有利于维持自身的免疫机能;(2)大鼠垂体SSTR-1对1次性运动应答性反应的规律与SST一致,即接受适宜运动训练的个体运动后即刻表达增多,处于运动应激动员和衰竭阶段的个体运动后即刻表达减少;(3)运动后即刻及安静状态下,过度训练均引起大鼠下丘脑SST及垂体SSTR-1表达减少,对于对抗免疫抑制的发展具有重要意义,是机体防御抑制保护的表现。     

Beating the bunker: the effect of PETTLEP imagery on golf bunker shot performance

The aim of this study was to compare the effects of physical practice with PETTLEP-based (Physical, Environment, Task, Timing, Learning, Emotion and Perspective; Holmes & Collins, 2001) imagery and PETTLEP + physical practice interventions on golf bunker shot performance. Thirty-two male county- or international-level golfers were assigned to one of four groups; PETTLEP imagery, physical practice, PETTLEP + physical practice, or control. The PETTLEP imagery group imaged 15 bunker shots, their interventions incorporating PETTLEP components, such as physical, environment, and emotion, twice a week. The physical practice group physically performed their 15 bunker shots twice per week; the PETTLEP + physical practice group performed PETTLEP imagery once per week and physical practice once per week. Each group performed their respective tasks for 6 weeks. Pre- and posttests consisted of 15 bunker shots, with points awarded according to the ball proximity to the pin. All groups improved significantly (p < .01) from pre- to posttest, and the PETTLEP + physical practice group improved more (p < .05) than the PETTLEP and physical practice groups. However, there was no significant difference between the physical practice and PETTLEP groups (p > .05). Findings, therefore, support the effectiveness of PETTLEP in enhancing golf performance, especially when combined with physical practice.