Effects of increasing and decreasing physiological arousal on anticipation timing performance during competition and practice

The aim of this study was to investigate if the effects of changes in physiological arousal on timing performance can be accurately predicted by the catastrophe model. Eighteen young adults (8 males, 10 females) volunteered to participate in the study following ethical approval. After familiarisation, coincidence anticipation was measured using the Bassin Anticipation Timer under four incremental exercise conditions: Increasing exercise intensity and low cognitive anxiety, increasing exercise intensity and high cognitive anxiety, decreasing exercise intensity and low cognitive anxiety and decreasing exercise intensity and high cognitive anxiety. Incremental exercise was performed on a treadmill at intensities of 30%, 50%, 70% and 90% heart rate reserve (HRR) respectively. Ratings of cognitive anxiety were taken at each intensity using the Mental Readiness Form 3 (MRF3) followed by performance of coincidence anticipation trials at speeds of 3 and 8 mph. Results indicated significant condition × intensity interactions for absolute error (AE; p = .0001) and MRF cognitive anxiety intensity scores (p = .05). Post hoc analysis indicated that there were no statistically significant differences in AE across exercise intensities in low–cognitive anxiety conditions. In high–cognitive anxiety conditions, timing performance AE was significantly poorer and cognitive anxiety higher at 90% HRR, compared to the other exercise intensities. There was no difference in timing responses at 90% HRR during competitive trials, irrespective of whether exercise intensity was increasing or decreasing. This study suggests that anticipation timing performance is negatively affected when physiological arousal and cognitive anxiety are high.     

不同运动强度对衰老小鼠血清干预效果的研究

目的：研究不同运动强度对D-半乳糖致衰老小鼠的抗氧化水平的影响,观察其延缓表老的效果。方法：将50只昆明小鼠,随机分为5组,分别为大运动强度．中等运动强度、小运动强度的运动干预组,衰老时照组和正常对照组。采用D-半乳糖皮下注射建立亚急性衰老模型。6周后测定血清中与抗衰老作用相关的超氧化物吱化酶（SOD）、谷胱甘肤过氧化物酶（GSH--PX）的活性及丙二醛（MDA）的含量。结果：运动干预组与衰老模型姐比较,大运动强度干预组小鼠血清SOD的活性有显著性改善（P〈0．05）,GSH-PX的活性和MDA的含量则无显著性差异;中等运动强度干预组血清SOD,GSH-PX活性均有显著性改（P〈0．05）,并且MDA的含量也有显著性改善（P〈0．05）;小运动强度干预组小鼠的血清SOD、GSH-PX的活性和MDA的含量则均无显著性差异。进一步分析表明,与衰老模型组比较,中等运动强度干预组血清SOD、GSH-PX活性和MDA@量的变化幅度均大于其它两种运动强度。结论：研究结果表明中等运动强度的干预能显著改善血清中与抗表老作用相关的血清SOD、GSH—PX的活性和MDA的含量。     

The effect of high intensity exercise and anticipation on trunk and lower limb biomechanics during a crossover cutting manoeuvre

We investigated the effects of high intensity, intermittent exercise (HIIP) and anticipation on trunk, pelvic and lower limb biomechanics during a crossover cutting manoeuvre. Twenty-eight male, varsity athletes performed crossover cutting manoeuvres in anticipated and unanticipated conditions pre- and post-HIIP. Kinematic and kinetic variables were captured using a motion analysis system. Statistical parametric mapping (repeated-measures ANOVA) was used to identify differences in biomechanical patterns. Results demonstrated that both unanticipation and fatigue (HIIP) altered the biomechanics of the crossover cutting manoeuvre, whereas no interactions effects were observed. Unanticipation resulted in less trunk and pelvic side flexion in the direction of cut (d = 0.70 – 0.79). This led to increased hip abductor and external rotator moments and increased knee extensor and valgus moments with small effects (d = 0.24–0.42), potentially increasing ACL strain. The HIIP resulted in trivial to small effects only with a decrease in internal knee rotator and extensor moment and decreased knee power absorption (d = 0.35), reducing potential ACL strain. The effect of trunk and hip control exercises in unanticipated conditions on the crossover cutting manoeuvre should be investigated with a view to refining ACL injury prevention programmes.     

葡萄籽提取物对运动员大强度运动后生化指标的影响研究

目的:研究葡萄籽提取物对运动员大运动量后生化指标影响。方法:以辽宁省女子皮划艇队为研究对象,服用葡萄籽提取物后,测定大强度力竭性运动前后几个抗氧化指标的变化,从而观察葡萄籽提取物对运动员延缓疲劳和保护运动损伤的作用效果。结果:葡萄籽提取物中含有的原花青素能够显著提高运动员谷胱甘肽过氧化物酶水平,同时,血浆超氧化物歧化酶的平均值也有一定程度的升高。结论:在短时力竭的运动中,葡萄籽提取物能够有效地保护细胞膜较少的受到过氧化物的攻击,从而延缓运动疲劳,减少运动损伤的发生。     

The effect of motivational music on sub-maximal exercise

Abstract

This study examined the effect of motivational music on a 20-min sub-maximal cycle task. Eighteen untrained student volunteers (10 males, 8 females) were required to partake in three experimental conditions: no music, oudeterous (non-motivational) music, and motivational music. Participants’ in-task affective states and rate of perceived exertion were assessed on rating scales during the trials and the distance traveled for each trial was recorded. In addition, participants’ attitudes towards the exercise experience were assessed on rating scales administered post-trial. The results of the study indicate that both motivational and oudeterous music can significantly increase distance traveled when compared to the control condition. However, no significant differences were observed between the two music conditions and the increased exercise intensity associated with musical accompaniments was not associated with an increased perception of effort. Both music conditions elicited increased in-task affect and generated equally positive post-task attitudes towards the exercise experience. No significant Gender×Trial interactions were identified for any of the dependent measures.     

The effects of frequency of encouragement on performance during maximal exercise testing

The aim of this study was to determine the effects of frequency of verbal encouragement during maximal exercise testing. Twenty-eight participants (12 males, 16 females) aged 20.9 - 1.5 years (mean - s ) performed a maximal exercise test ( V O 2max ) on a treadmill without any verbal encouragement. The participants were matched according to their pre-test V O 2max and placed into either a control group or one of three experimental groups. They performed a second exercise test (post-test) 1 week later. During the second test, the control group received no verbal encouragement; the 20 s (20E), 60 s (60E) and 180 s (180E) encouragement groups received verbal encouragement every 20, 60 and 180 s, respectively, beginning with stage 3 of the exercise test. Relative V O 2max , exercise time, blood lactate concentration, respiratory exchange ratio (RER) and ratings of perceived exertion (RPE) were not significantly different from the first test to the second test for the control group without verbal encouragement and the 180E group that received infrequent encouragement. Post-test values were significantly higher than pre-test values for the 20E and 60E groups. The post-test values of the 20E group were significantly higher than their pre-test values for relative V O 2max ( P ? 0.001), exercise time ( P ? 0.0001), blood lactate concentr . ation ( P ? 0.05), RER ( P ? 0.01) and RPE ( P ? 0.0001); this was also the case for the 60E group for relative V O 2max ( P ? 0.01), blood lactate concentration ( P ? 0.05), RER ( P ? 0.05) and RPE ( P ? 0.05). The results suggest that frequent verbal encouragement (every 20 s and 60 s in the present study) leads to significantly greater maximum effort in a treadmill test than when no encouragement is given or when the encouragement is infrequent (i.e. every 180 s).     

The time-frame of acute resistance exercise effects on football skill performance: The impact of exercise intensity

Abstract

The purpose of this study was to determine the recovery rate of football skill performance following resistance exercise of moderate or high intensity. Ten elite football players participated in three different trials: control, low-intensity resistance exercise (4 sets, 8–10 repetitions/set, 65–70% 1 repetition maximum [1RM]) and high-intensity resistance exercise (4 sets, 4–6 repetitions/set, 85–90% 1RM) in a counterbalanced manner. In each experimental condition, participants were evaluated pre, post, and at 24, 48, 72 h post exercise time points. Football skill performance was assessed through the Loughborough Soccer Passing Test, long passing, dribbling, shooting and heading. Delayed onset muscle soreness, knee joint range of motion, and muscle strength (1RM) in squat were considered as muscle damage markers. Blood samples analysed for creatine kinase activity, C-reactive protein, and leukocyte count. Passing and shooting performance declined (P < 0.05) post-exercise following resistance exercise. Strength declined post-exercise following high-intensity resistance exercise. Both trials induced only a mild muscle damage and inflammatory response in an intensity-dependent manner. These results indicate that football skill performance is minimally affected by acute resistance exercise independent of intensity suggesting that elite players may be able to participate in a football practice or match after only 24 h following a strength training session.     

Physiological intensity profile,exercise load and performance predictors of a 65-km mountain ultra-marathon

The aims of the study were to describe the physiological profile of a 65-km (4000-m cumulative elevation gain) running mountain ultra-marathon (MUM) and to identify predictors of MUM performance. Twenty-three amateur trail-runners performed anthropometric evaluations and an uphill graded exercise test (GXT) for VO_2max, ventilatory thresholds (VTs), power outputs (PMax, PVTs) and heart rate response (HRmax, HR@VTs). Heart rate (HR) was monitored during the race and intensity was expressed as: Zone I (VT2) for exercise load calculation (training impulse, TRIMP). Mean race intensity was 77.1%±4.4% of HRmax distributed as: 85.7%±19.4% Zone I, 13.9%±18.6% Zone II, 0.4%±0.9% Zone III. Exercise load was 766±110 TRIMP units. Race time (11.8±1.6h) was negatively correlated with VO_2max (r = ?0.66, P <0.001) and PMax (r = ?0.73, P <0.001), resulting these variables determinant in predicting MUM performance, whereas exercise thresholds did not improve performance prediction. Laboratory variables explained only 59% of race time variance, underlining the multi-factorial character of MUM performance. Our results support the idea that VT1 represents a boundary of tolerable intensity in this kind of events, where exercise load is extremely high. This information can be helpful in identifying optimal pacing strategies to complete such extremely demanding MUMs.     

主观用力感觉在预测心脏康复适宜运动度中的作用

目的:探讨主观用力感觉(RPE)在预测急性期后心梗患者(PMIP)对运动的生理和临床反应中的作用,这将有利于适宜运动强度的制定。方法:46名服用β阻断剂的男性PMIP(年龄60.9±7.5岁)5,5名未服用β阻断剂的男性PMIP(年龄63.6±7.3岁)在活动跑台上进行递增负荷实验,终止实验的标准依美国运动医学会的指南(ACSM)或病人的主观要求。运动中每30 s测量一次摄氧量(VO2)和通气量(VE)、每3 min记录一次心率(HR),血乳酸(BL)和主观用力感觉(RPE),并连续监测12导心电图。结果:两组病人在VO2,BL,VE和ST段降低与RPE的关系方面无显著差异(P>0.05)。然而,在运动实验过程中,两组病人在心率方面有显著差异(P<0.01)。无论是服用还是未服用β阻断剂的PMIP,RPE达到13都是其运动中有氧代谢向无氧代谢过渡的转折点。结论:基于以上结果,建议PMIP在运动心脏康复中感觉到"稍费力"时即不应再加大运动强度。     

The effects of eccentric exercise-induced muscle damage on running kinematics at different speeds

Abstract

This study investigated the effects of knee localised muscle damage on running kinematics at varying speeds. Nineteen young women (23.2 ± 2.8 years; 164 ± 8 cm; 53.6 ± 5.4 kg), performed a maximal eccentric muscle damage protocol (5 × 15) of the knee extensors and flexors of both legs at 60 rad · s^-1. Lower body kinematics was assessed during level running on a treadmill at three speeds pre- and 48 h after. Evaluated muscle damage indices included isometric torque, muscle soreness and serum creatine kinase activity. The results revealed that all indices changed significantly after exercise, indicating muscle injury. Step length decreased and stride frequency significantly increased 48 h post-exercise only at the fastest running speed (3 m · s^-1). Support time and knee flexion at toe-off increased only at the preferred transition speed and 2.5 m · s^-1. Knee flexion at foot contact, pelvic tilt and obliquity significantly increased, whereas hip extension during stance-phase, knee flexion during swing-phase, as well as knee and ankle joints range of motion significantly decreased 48 h post-exercise at all speeds. In conclusion, the effects of eccentric exercise of both knee extensors and flexors on particular tempo-spatial parameters and knee kinematics of running are speed-dependent. However, several pelvic and lower joint kinematics present similar behaviour at the three running speeds examined. These findings provide new insights into how running kinematics at different speeds are adapted to compensate for the impaired function of the knee musculature following muscle damage.     

The influence of carbohydrate and protein ingestion during recovery from prolonged exercise on subsequent endurance performance

Abstract

Ingesting carbohydrate plus protein following prolonged exercise may restore exercise capacity more effectively than ingestion of carbohydrate alone. The objective of the present study was to determine whether this potential benefit is a consequence of the protein fraction per se or simply due to the additional energy it provides. Six active males participated in three trials, each involving a 90-min treadmill run at 70% maximal oxygen uptake (run 1) followed by a 4-h recovery. At 30-min intervals during recovery, participants ingested solutions containing: (1) 0.8 g carbohydrate · kg body mass (BM)^?1 · h^?1 plus 0.3 g · kg^?1 · h^?1 of whey protein isolate (CHO-PRO); (2) 0.8 g carbohydrate · kg BM^?1 · h^?1 (CHO); or (3) 1.1 g carbohydrate · kg BM^?1 · h^?1 (CHO-CHO). The latter two solutions matched the CHO-PRO solution for carbohydrate and for energy, respectively. Following recovery, participants ran to exhaustion at 70% maximal oxygen uptake (run 2). Exercise capacity during run 2 was greater following ingestion of CHO-PRO and CHO-CHO than following ingestion of CHO (P ≤ 0.05) with no significant difference between the CHO-PRO and CHO-CHO treatments. In conclusion, increasing the energy content of these recovery solutions extended run time to exhaustion, irrespective of whether the additional energy originated from sucrose or whey protein isolate.     

Effects of weightlifting exercise,traditional resistance and plyometric training on countermovement jump performance: a meta-analysis

Jump performance is considered an important factor in many sports. Thus, strategies such as weightlifting (WL) exercises, traditional resistance training (TRT) and plyometric training (PT) are effective at improving jump performance. However, it is not entirely clear which of these strategies can enable greater improvements on jump height. Thus, the purpose of the meta-analysis was to compare the improvements on countermovement jump (CMJ) performance between training methods which focus on WL exercises, TRT, and PT. Seven studies were included, of which one study performed both comparison. Therefore, four studies comparing WL exercises vs. TRT (total n = 78) and four studies comparing WL exercises vs. PT (total n = 76). The results showed greater improvements on CMJ performance for WL exercises compared to TRT (ES_diff: 0.72 ± 0.23; _95%CI: 0.26, 1.19; P = 0.002; Δ % = 7.5 and 2.1, respectively). The comparison between WL exercises vs. PT revealed no significant difference between protocols (ES_diff: 0.15 ± 0.23; _95%CI: ?0.30, 0.60; P = 0.518; Δ % = 8.8 and 8.1, respectively). In conclusion, WL exercises are superior to promote positive changes on CMJ performance compared to TRT; however, WL exercises and PT are equally effective at improving CMJ performance.     

The effect of 10 days of intermittent fasting on Wingate anaerobic power and prolonged high-intensity time-to-exhaustion cycling performance

Many physically active individuals have undertaken intermittent fasting to reduce their daily caloric intake. However, abstaining from meals for a specific length of time may lead to the acute disturbance of highly carbohydrate-dependent exercise performance. The purpose of this study was to observe the effect of 10 days of intermittent fasting on high-intensity type exercises, Wingate anaerobic (WT) and prolonged high-intensity time-to-exhaustion (HIT) cycling test. Twenty participants were randomised into an intermittent fasting (FAS) and a control group (CON). One day after baseline data collection on Day-0 where participants consumed their recommended daily caloric intake (FAS?=?2500?±?143?kcal?day^?1; CON?=?2492?±?20?kcal?day^?1) served over a course of five meals, the FAS group consumed only four meals where 40% was restricted by the omission of lunch (FAS?=?1500?±?55?kcal?day^?1). This diet was then continued for 10 days. Data on exercise performance and other dependent variables were collected on Day-2, -4, -6, -8 and -10. A reduction in WT power in the FAS group was observed on Day-2 (821.74?±?66.07?W) compared to Day-0 (847.63?±?95.94?W) with a moderate effect size (p?p?p?相似文献   

运动强度和运动量对血液免疫指标影响程度的比较研究

目的:通过比较不同强度和持续时间的体育锻炼形式对机体血液免疫指标等方面的影响,为正确选择最佳健身方式提供参考依据,进而避免超大运动负荷对机体的损害。方法:受试者分为大、中、小强度练习组,每个练习组又按运动时间分为三个小组。在程控跑台上分别进行为期三个月的练习。从免疫球蛋白的含量、循环免疫复合物(CIC)含量、红细胞总数、白细胞分类计数、红细胞(RBC)-SOD的活性、血浆丙二醛(MDA)浓度等方面进行测试。结果表明:运动量对血液免疫指标的影响要比运动强度大。     

不同强度的耐力运动对糖尿病大鼠肾脏氧化应激与TIMP-1表达的影响

目的:探讨不同运动强度的耐力运动对糖尿病大鼠肾脏氧化应激及基质金属蛋白酶组织抑制物-1(TIMP-1)的影响。方法:以体重190±15 g SD雄性大鼠为研究对象,经6周高脂高糖膳食喂养并腹腔注射链脲佐菌素建立糖尿病模型后,将糖尿病大鼠分为糖尿病对照组(DMC),糖尿病运动Ⅰ组(DME1,跑速为10 m/min),糖尿病运动Ⅱ组(DME2,跑速为15 m/min),糖尿病运动3组(DME3,跑速为20m/min),运动组每天1小时跑台运动,每周5天,持续6周。6周末检测血糖、胰岛素,肾脏组织内MDA、SOD、CAT及TIMP-1的含量或活性。结果:与对照组相比,运动组血糖均著下降(P<0.01),而运动组血清胰岛素均呈上升趋势,且DME3组显著上升(P<0.05),但运动1组、运动2组胰岛素抵抗指数显著下降(P<0.05);而运动1组与运动2组MDA显著下降(P<0.05,P<0.01);同时,各运动组抗氧化酶均呈上升趋势,其中T-SOD含量上升均具有显著性或极显著性差异,低强度、中强度运动组CAT含量显著高于对照组(P<0.01);而运动组TIMP-1表达水平显著或极显著下降(P<0.05,P<0.01)。结论:10 m/min、15 m/min强度耐力运动可有效地控制降低血糖,改善胰岛素抵抗,提高糖尿病大鼠抗氧化防御系统,防止肾脏纤维化,有利于控制糖尿病进一步恶化。     

有氧代谢能力与耐力项目训练中运动强度的选择

全面阐述了有氧代谢能力的概念，提出了最大摄氧量、无氧阈、最大摄氧量平台的持续时间都应是耐力训练的目标。在此基础上讨论了发展此3项目标应采用的训练强度。     

Effect of body composition on redox homeostasis at rest and in response to exercise: The case of underfat women

Underfat individuals have been neglected as a malnourished population in terms of redox homeostasis. The aim of the present study was to evaluate the effect of body composition on redox homeostasis at rest and in response to exercise. Underfat, lean and overfat women, classified according to their BMI and body fat percentage, participated in the study and were subjected to an acute session of eccentric exercise. With regard to muscle function and damage, a significant group × time interaction was found for range of motion (P < .01), isometric peak torque at 90° (P < .01), delayed onset muscle soreness (P < .01) and creatine kinase (P < .05), with the lean group generally exhibiting faster recovery compared to the underfat and overfat groups. With regard to redox homeostasis, a significant group × time interaction was found for F₂-isoprostanes, protein carbonyls and glutathione (P < .01 for all biomarkers), with the underfat and overfat groups exhibiting increased resting oxidative stress levels and lower exercise-induced reactive species production . In conclusively, our data underline the importance of normal body composition for redox homeostasis, since underfat and overfat women demonstrate a similar pattern of redox disturbances both at rest and in response to exercise.     

Effects of exercise intensity on salivary antimicrobial proteins and markers of stress in active men

Abstract

In the present study, we assessed the effects of exercise intensity on salivary immunoglobulin A (s-IgA) and salivary lysozyme (s-Lys) and examined how these responses were associated with salivary markers of adrenal activation. Using a randomized design, 10 healthy active men participated in three experimental cycling trials: 50% maximal oxygen uptake ([Vdot]O_2max), 75%[Vdot]O_2max, and an incremental test to exhaustion. The durations of the trials were the same as for a preliminary incremental test to exhaustion (22.3 min, s _x  = 0.8). Timed, unstimulated saliva samples were collected before exercise, immediately after exercise, and 1 h after exercise. In the incremental exhaustion trial, the secretion rates of both s-IgA and s-Lys were increased. An increase in s-Lys secretion rate was also observed at 75%[Vdot]O_2max. No significant changes in saliva flow rate were observed in any trial. Cycling at 75%[Vdot]O_2max and to exhaustion increased the secretion of α-amylase and chromogranin A immediately after exercise; higher cortisol values at 75%[Vdot]O_2max and in the incremental exhaustion trial compared with 50%[Vdot]O_2max were observed 1 h immediately after exercise only. These findings suggest that short-duration, high-intensity exercise increases the secretion rate of s-IgA and s-Lys despite no change in the saliva flow rate. These effects appear to be associated with changes in sympathetic activity and not the hypothalamic – pituitary – adrenal axis.     

空气负氧离子对老年人健身锻炼效果的影响

采用文献资料、逻辑分析及归纳等方法,对老年人尤其高龄老年人特殊的身心特征、健身运动的特点及负氧离子对人体健康的作用进行了分析。通过探讨空气负氧离子对人体健身锻炼的有益效果,旨在为老年人尤其高龄老年人健身锻炼环境的选择提供理论指导。研究认为,老年人体质下降明显,尤其心肺功能的明显下降往往致使他们在健身锻炼过程中时常感到心有余而力不足,进而影响健身锻炼的效果,而负氧离子又称空气维生素,高浓度负氧离子的吸入可以弥补人体氧供应的缺失和不足,有益于提高健身锻炼的效率。     

The effect of heavy resistance exercise on repeated sprint performance in youth athletes

This investigation assessed whether prior heavy resistance exercise would improve the repeated sprint performance of 16 trained youth soccer players (Age 17.05 ± 0.65 years; height 182.6 ± 8.9 cm; body mass 77.8 ± 8.2 kg). In session 1, individual 1 repetition max was measured utilising a squat movement. In sessions 2 and 3, participants performed a running-based repeated anaerobic sprint test with and without prior heavy resistance exercise of 91% of their 1 repetition max. Times were recorded for each of the 6 sprints performed in the repeated sprint test and summed to provide total time. T-tests compared the two exercise conditions via differences in corresponding sprint times and total time. Analysis revealed significantly reduced total time with use of heavy resistance exercise (33.48 (±1.27) vs. 33.59 (±1.27); P = 0.01). Sprints 1 (P = 0.05) and 2 (P = 0.02) were also faster in the heavy resistance exercise condition (5.09 (±0.16) vs. 5.11 (±0.16) and 5.36 (±0.24) vs. 5.45 (±0.26) seconds respectively) although no other differences were shown. Findings demonstrate improved sprint times of trained adolescent soccer players after heavy resistance exercise although benefits appear not as sustained as in adult participants.