力竭运动对小鼠骨骼肌氧化应激和DNA损伤的影响

目的:研究力竭运动对小鼠骨骼肌氧化应激和DNA损伤的影响,探讨骨骼肌细胞DNA损伤的氧化损伤机制,进一步揭示运动性疲劳的损伤机理;方法:采用单细胞凝胶电泳对力竭运动小鼠不同恢复期骨骼肌细胞的DNA损伤效应进行测定;结果:小鼠骨骼肌细胞在大强度力竭运动后即刻和24 h的DNA损伤显著高于对照组损伤水平(P＜0.05),其中即刻组的DNA损伤程度最为显著(P＜0.01),而运动后48 h彗星各项指标与对照组的差异无统计学意义(P＞0.05);结论:力竭运动所致的骨骼肌细胞DNA损伤与氧化应激水平有密切的关系,运动性氧应激参与介导了细胞DNA损伤,运动性氧应激是组织细胞DNA损伤的机制之一,适时有效的抗氧化剂补充将有利于防护组织细胞DNA损伤.     

Effects of endurance and high-intensity swimming exercise on the redox status of adolescent male and female swimmers

Abstract

Throughout adolescence, swimmers begin to carry out demanding endurance and high-intensity training sets, the effect of which on redox status is largely unknown. The aim of the present study was to investigate the effects of 2000-m continuous swimming and 6 × 50-m maximal swimming on the redox status of adolescent swimmers. Fifteen male and 15 female swimmers, aged 14–18 years, provided blood samples before, immediately after, 1 h after, and 24 h after each exercise for the determination of redox status parameters. Oxidative damage was short-lived and manifest as increases in 8-hydroxy-2?-deoxyguanosine (8-OHdG) 1 h after high-intensity exercise (39%, P < 0.001) and in malondialdehyde immediately after both exercises (65%, P < 0.001). Alterations in antioxidant parameters were sustained during recovery: reduced glutathione decreased 24 h post-exercise (11%, P = 0.001), uric acid increased gradually after high-intensity exercise (29%, P < 0.001) and bilirubin peaked 24 h post-exercise (29%, P < 0.001). Males had higher 8-OHdG (49%, P = 0.001) and uric acid (29%, P < 0.001) concentrations than females. However, females showed higher values of malondialdehyde than males immediately post-exercise (30%, P = 0.039), despite lower pre-exercise values. In conclusion, both endurance and high-intensity exercise perturbed the redox balance without inducing prolonged oxidative damage in trained adolescent male and female swimmers. These swimming training trials were not found to be detrimental to the redox homeostasis of adolescents.     

氧化应激在衰老性肌萎缩中的作用机理与运动干预探讨

与衰老相关的骨骼肌质量、力量下降称为衰老性肌萎缩.衰老时骨骼肌内氧化应激增强会导致线粒体机能下降、分子炎症,这些因素相互作用诱导肌纤维凋亡,并干扰蛋白质代谢平衡,这可能是衰老性肌萎缩的重要机制.遗传操作研究和运动锻炼研究已证明转录辅激活因子PGC-1α表达增强有利于降低ROS生成并增强线粒体生物合成,降低炎症基因转录.激活蛋白激酶Akt可促进肌肉蛋白质合成,还可抑制蛋白质分解和凋亡.通过运动训练调节PGC-1α、Akt的表达和活性可能是运动干预部分地逆转衰老性肌萎缩的内在机制.探讨衰老性肌萎缩的细胞分子机制及运动干预的作用,在此基础上提出未来研究的方向.     

Mechanisms of beneficial effects of exercise training on non-alcoholic fatty liver disease (NAFLD): Roles of oxidative stress and inflammation

Abstract

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disorder which is associated with accumulation of fats in the liver. It causes a wide variety of pathological effects such as non-alcoholic steatohepatitis (NASH) and cirrhosis, insulin resistance, obesity, hypertension, dyslipidaemia, diabetes and cardiovascular disease. The molecular mechanisms that cause the initiation and progression of NAFLD are not fully understood. Oxidative stress (OS) induced by reactive oxygen species (ROS) and inflammation are likely a significant mechanism which can lead to hepatic cell death and tissue injury. Mitochondrial abnormalities, down-regulation of several antioxidant enzymes, glutathione (GSH) depletion and decreased activity of GSH-dependent antioxidants, accumulation of leukocytes and hepatic inflammation are the major sources of ROS overproduction in NAFLD. Excessive production of ROS suppresses the capacity of other antioxidant defence systems in NAFLD and causes further oxidative damage. Regular exercise can be considered as an effective strategy for treatment of NAFLD. It improves NAFLD by reducing intrahepatic fat content, increasing β-oxidation of fatty acids, inducing hepato-protective autophagy, overexpressing peroxisome proliferator-activated receptor- γ (PPAR-γ), as well as attenuating hepatocyte apoptosis and increasing insulin sensitivity. Exercise training also suppresses ROS overproduction and OS in NAFLD via up-regulation of several antioxidant enzymes and anti-inflammatory mediators. Therefore, an understanding of these molecules and signalling pathways gives us valuable information about NAFLD progression and a method for developing a suitable clinical treatment. This review aimed to evaluate sources of ROS and OS in NAFLD and the molecular mechanisms involved in the beneficial effects of exercises on NAFLD.     

Transition phase clothing strategies and their effect on body temperature and 100-m swimming performance

Objective: Effective warm-ups are attributed to several temperature-related mechanisms. Strategies during the transition phase, preceding swimming competition, have been shown to prolong temperature-related warm-up effects. The purpose of this study was to evaluate the effects of two different clothing strategies during the transition phase, on subsequent 100-m maximal swimming performance. Methods: Nine competitive swimmers (3 female, 21?±?3?yrs; 6 male 20?±?2?yrs, mean performance standard 702 FINA Points, mean 100-m seasons best time 61.54?s) completed their own 30-min individual pool warm-up, followed by 7-min changing time and a 30-min transition phase, straight into a 100-m maximal effort time-trial. During the transition phase, swimmers remained seated, either wearing warm or limited clothing. Swimmers returned 1 week later, where clothing conditions were alternated. Results: Post-transition phase skin and core temperature remained higher in the warm clothing condition compared to the limited clothing condition (Mean Core: 36.90?±?0.17°C, 36.61?±?0.15°C, P?P?P?Conclusion: Wearing warm clothing during a 30-min transition phase improved swimming performance by 0.6%, compared to limited clothing.     

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   

The effect of vibration on active and passive range of motion in elite female synchronized swimmers

Abstract

The purpose of this study was to assess the acute effects of vibration and stretching on passive and active forward split range of motion in elite adult female synchronized swimmers. Eleven athletes performed a passive forward split test measuring the height of the anterior superior iliac spine on both sides and an active split test on both sides by adopting an inverted split position. Then athletes were assigned randomly by right or left leg to receive vibration on one leg while stretching. The contralateral leg was stretched but did not receive vibration and served as the control. The treatment involved a 40-s exposure to vibration of the forward leg in a split and 40 s of vibration to the rear leg in a split. The athletes were then post-tested using the same protocols. The results indicated that the vibration had a statistically significant influence on passive forward split flexibility, but not active split flexibility. The results of this study confirm earlier work and further demonstrate the efficacy of vibration in enhancing range of motion in a passive split position. Given that it is often difficult to achieve large changes in range of motion with already highly trained elite athletes, this methodology shows considerable promise. Vibration may not be powerful enough to evoke changes in active range of motion in spite of the changes in passive range of motion.     

The effect of exercise interventions on resting metabolic rate: A systematic review and meta-analysis

ABSTRACT

The systematic review and meta-analysis evaluated the effect of aerobic, resistance and combined exercise on RMR (kCal·day^-1) and performed a methodological assessment of indirect calorimetry protocols within the included studies. Subgroup analyses included energy/diet restriction and body composition changes. Randomized control trials (RCTs), quasi – RCTs and cohort trials featuring a physical activity intervention of any form and duration excluding single exercise bouts were included. Participant exclusions included medical conditions impacting upon RMR, the elderly (≥65 years of age) or pregnant, lactating or post-menopausal women. The review was registered in the International Prospective Register of Systematic Reviews (CRD 42,017,058,503). 1669 articles were identified; 22 were included in the qualitative analysis and 18 were meta-analysed. Exercise interventions (aerobic and resistance exercise combined) did not increase resting metabolic rate (mean difference (MD): 74.6 kCal·day^-1[95% CI: ?13.01, 161.33], P = 0.10). While there was no effect of aerobic exercise on RMR (MD: 81.65 kCal·day^-1[95% CI: ?57.81, 221.10], P = 0.25), resistance exercise increased RMR compared to controls (MD: 96.17 kCal·day^-1[95% CI: 45.17, 147.16], P = 0.0002). This systematic review effectively synthesises the effect of exercise interventions on RMR in comparison to controls; despite heterogenous methodologies and high risk of bias within included studies.     

对Paul等“高住低练对高水平游泳运动员红细胞生成和有氧运动能力的影响”一文的述评

高住低练指在运动员居住在相对较高的海拔高度,接受低氧暴露,同时在平原训练的一种科学化训练方法。多年来,高住低练对人体机能和运动能力的影响一直是研究的热点。高住低练可以在一定程度上提高运动员回到平原后的运动能力,创造好成绩,也得到了广大教练员和运动员的认同,高原低氧暴露对人体器官系统机能的影响也得到了更为深入的研究。发表在《Eur J Appl Physiol》2006年第96卷第4期上Paul Robach等人的论文“高住低练对高水平游泳运动员红细胞生成和有氧运动的影响”探讨了优秀游泳运动员在高住低练期间血液红细胞系指标的变化规律,以及对运动员有氧运动能力的影响,为高水平游泳运动员进行高住低练提供了实验依据。     

No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise

Abstract

Glutamine enhances the exercise-induced expansion of the tricarboxylic acid intermediate pool. The aim of the present study was to determine whether oral glutamine, alone or in combination with hyperoxia, influenced oxidative metabolism and cycle time-trial performance. Eight participants consumed either placebo or 0.125 g · kg body mass^?1 of glutamine in 5 ml · kg body mass^?1 placebo 1 h before exercise in normoxic (control and glutamine respectively) or hyperoxic (FiO₂ = 50%; hyperoxia and hyperoxia + glutamine respectively) conditions. Participants then cycled for 6 min at 70% maximal oxygen uptake ([Vdot]O_2max) immediately before completing a brief high-intensity time-trial (～4 min) during which a pre-determined volume of work was completed as fast as possible. The increment in pulmonary oxygen uptake during the performance test (Δ[Vdot]O_2max, P = 0.02) and exercise performance (control: 243 s, s _x  = 7; glutamine: 242 s, s _x  = 3; hyperoxia: 231 s, s _x  = 3; hyperoxia + glutamine: 228 s, s _x  = 5; P < 0.01) were significantly improved in hyperoxic conditions. There was some evidence that glutamine ingestion increased Δ[Vdot]O_2max in normoxia, but not hyperoxia (interaction drink/FiO₂, P = 0.04), but there was no main effect or impact on performance. Overall, the data show no effect of glutamine ingestion either alone or in combination with hyperoxia, and thus no limiting effect of the tricarboxylic acid intermediate pool size, on oxidative metabolism and performance during maximal exercise.     

Effects of pre-competitional rapid weight loss on nutrition,vitamin status and oxidative stress in elite boxers

Dietary intake, vitamin status and oxidative stress were evaluated in 17 elite male boxers. Ten of them frequently reduced body weight rapidly before competitions (Weight Loss Group) and 7 did not practice rapid weight loss (Control Group). Food record checklists, blood samples for determination of vitamin status and plasma glutathione levels were obtained during a week of weight maintenance, a pre-competition week and a post-competition week. The average dietary intakes in both groups were 33 ± 8 kcal·kg^?1, 3.7 ± 1.1 g·kg^?1 carbohydrates, 1.5 ± 0.4 g·kg^?1 protein, 1.2 ± 0.4 g·kg^?1 fat and 2.2 ± 1.0 L water per day (excluding pre-competition week in Weight Loss Group). Energy (18 ± 7 kcal·kg^?1), carbohydrate (2.2 ± 0.8 g·kg^?1), protein (0.8 ± 0.4 g·kg^?1), fat (0.6 ± 0.3 g·kg^?1) and water (1.6 ± 0.6 L) consumption (P-values <0.001) and intakes of most vitamins (P-values < 0.05) were significantly reduced during the pre-competition week in the Weight Loss Group. In both groups, the intakes of vitamins A, E and folate were below recommended values throughout the three periods; however, blood vitamin and plasma glutathione levels did not change significantly. Our findings indicate a low-caloric and low-carbohydrate diet in elite boxers, regardless of participating in rapid weight loss or not. Apparently, the pre-competitional malnutitrition in the Weight Loss Group did not induce alterations in the vitamin and glutathione status.     

The effect of exercise-induced muscle damage on isometric and dynamic knee extensor strength and vertical jump performance

In this study, we assessed the effect of exercise-induced muscle damage on knee extensor muscle strength during isometric, concentric and eccentric actions at 1.57 rad · s -1 and vertical jump performance under conditions of squat jump, countermovement jump and drop jump. The eight participants (5 males, 3 females) were aged 29.5 - 7.1 years (mean - s ). These variables, together with plasma creatine kinase (CK), were measured before, 1 h after and 1, 2, 3, 4 and 7 days after a bout of muscle damaging exercise: 100 barbell squats (10 sets 2 10 repetitions at 70% body mass load). Strength was reduced for 4 days ( P ? 0.05) but no significant differences ( P > 0.05) were apparent in the magnitude or rate of recovery of strength between isometric, concentric and eccentric muscle actions. The overall decline in vertical jump performance was dependent on jump method: squat jump performance was affected to a greater extent than countermovement (91.6 - 1.1% vs 95.2 - 1.3% of pre-exercise values, P ? 0.05) and drop jump (95.2 - 1.4%, P ? 0.05) performance. Creatine kinase was elevated ( P ? 0.05) above baseline 1 h after exercise, peaked on day 1 and remained significantly elevated on days 2 and 3. Strength loss after exercise-induced muscle damage was independent of the muscle action being performed. However, the impairment of muscle function was attenuated when the stretch-shortening cycle was used in vertical jumping performance.     

Effect of stride length manipulation on symptoms of exercise-induced muscle damage and the repeated bout effect

This study assessed the effects of stride length on symptoms of exercise-induced muscle damage after downhill running and whether the extent of the symptoms sustained in a repeated bout of downhill running are influenced by stride length manipulation in the first bout. Eighteen males aged 21.1 - 0.6 years (mean - s) were allocated to one of three groups for bout one: preferred stride frequency, overstride and understride. Bout two was performed 2 weeks later at the participants' preferred stride frequency. Maximal isometric force and perceived muscle soreness were assessed pre-test and 30 min, 24, 48 and 72 h post-exercise for each downhill run. Threefactor analyses of variance with repeated measures on time and bout were used for analysis. Results revealed a three-way interaction for soreness (F 8,60 = 3.56, P ? 0.05) and relative isometric strength (F 5.0,37.8 = 3.2, P ? 0.05). Post-hoc analyses revealed that, after bout one, the overstride group perceived most soreness and the understride group retained most strength. After the second bout, the overstride and preferred stride frequency groups perceived less soreness than the preferred stride frequency group in bout one. Strength retention was greater after bout two for all groups. In conclusion, strength retention after a repeated bout appears to be independent of the damage experienced in the initial bout of downhill running. However, understriding may provide least protection against soreness in a subsequent bout.     

The effect of low-volume high-intensity interval training on cardiometabolic health and psychological responses in overweight/obese middle-aged men

ABSTRACT

High-intensity interval training (HIIT) has been proposed as a time-efficient exercise protocol to improve metabolic health, but direct comparisons with higher-volume moderate-intensity continuous training (MICT) under unsupervised settings are limited. This study compared low-volume HIIT and higher-volume MICT interventions on cardiometabolic and psychological responses in overweight/obese middle-aged men. Twenty-four participants (age: 48.1±5.2yr; BMI: 25.8±2.3kg·m^?2) were randomly assigned to undertake either HIIT (10 X 1-min bouts of running at 80–90% HR_max separated by 1-min active recovery) or MICT (50-min continuous jogging/brisk walking at 65–70% HR_max) for 3 sessions/week for 8 weeks (2-week supervised + 6-week unsupervised training). Both groups showed similar cardiovascular fitness (VO_2max) improvement (HIIT: 32.5±5.6 to 36.0±6.2; MICT: 34.3±6.0 to 38.2±5.1mL kg^?1 min^?1, p < 0.05) and %fat loss (HIIT: 24.5±3.4 to 23.2±3.5%; MICT: 23.0±4.3 to 21.5±4.1%, p< 0.05) over the 8-week intervention. Compared to baseline, MICT significantly decreased weight and waist circumference. No significant group differences were observed for blood pressure and cardiometabolic blood markers such as lipid profiles, fasting glucose and glycated haemoglobin. Both groups showed similar enjoyment levels and high unsupervised adherence rates (>90%). Our findings suggest that low-volume HIIT can elicit a similar improvement of cardiovascular fitness as traditional higher-volume MICT in overweight/obese middle-aged men.     

体育考试应激对大学生心理状况及考试成绩的影响

采用症状自评量表对大学二年级学生体育考试前进行了心理健康状况调查.结果表明,除恐怖因子外,其余各因子皆有非常显著差异(P＜0.01);女生心理状况及考试成绩优于男生;SCL-90各因子痛苦水平与考试成绩呈显著负相关.     

身体活动与心理健康效应研究进展评述

通过文献综述对身体活动与心理健康效应研究的现状进行分析,在已有研究的基础上,探讨最佳的活动方式与最大的心理效应,提出存在的问题以及今后的努力方向.     

抗阻力练习对中老年人体质健康影响研究述评

中老年健身的一般性指导原则是采用“长距离、慢速耐力运动”锻炼方案以达到促进心肺系统功能改善，从而达到健身的目的。然而，越来越多的研究证实：抗阻力练习不仅对肌肉-骨骼肌系统机能的保持有显著效果（这对预防骨质疏松、腰背部疼痛以及其他功能障碍有积极效果），还对胰岛素抵抗、静息代谢率、葡萄糖代谢、血压、身体脂肪以及肠胃功能等机能的维持有积极作用（这些因素与肥胖症、心脏病、癌症的发病率有关）。抗阻力练习应该作为疾病预防、体质改善的核心内容，而不是次要的或外围性手段。     

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。     

Effects of 6-month soccer and traditional physical activity programmes on body composition,cardiometabolic risk factors,inflammatory, oxidative stress markers and cardiorespiratory fitness in obese boys

Physical activity is important in obesity prevention, but the effectiveness of different physical activity modalities remains to be determined among children. The main purpose of this study was to compare the effects of a 6-month soccer programme and a traditional physical activity programme on changes in body composition, cardiometabolic risk factors, inflammatory and oxidative markers, cardiorespiratory fitness and perceived psychological status in obese boys. Eighty-eight boys (8–12 years; BMI > +2 standard deviations of WHO reference values) participated in one of three groups: soccer, traditional activity and control. Soccer and traditional activity programmes involved 3 sessions per week for 60–90 min at an average intensity of 70–80% of maximal heart rate. Control group participated in activities of normal daily living. All boys participated in school physical education, two sessions per week of 45–90-min. Measurements were taken at baseline and after 6 months, and included body size and composition, cardiometabolic risk factors, inflammatory and oxidative markers, cardiorespiratory fitness and perceived psychological status. Physical activity and dietary intake were assessed before and immediately following the intervention. The three groups had similar characteristics at baseline. After 6 months, both intervention groups had significantly lower relative fatness (% fat), waist circumference and total cholesterol, and higher cardiorespiratory fitness, self-esteem, perceived physical competence and attraction to physical activity compared with control group. In conclusion, physical activity interventions over 6 months positively influenced several indicators of health status among obese boys. The results also suggested that soccer has the potential as an effective tool for the prevention and reduction of childhood obesity and associated consequences.     

A single bout of high-intensity interval exercise and work-matched moderate-intensity exercise has minimal effect on glucose tolerance and insulin sensitivity in 7- to 10-year-old boys

The purpose of this study was to assess the acute effect of high-intensity interval exercise (HIIE) and moderate-intensity exercise (MIE) on glucose tolerance, insulin sensitivity and fat oxidation in young boys. Eleven boys (8.8 ± 0.8 y) completed three conditions: 1) HIIE; 2) work-matched MIE; and 3) rest (CON) followed by an oral glucose tolerance test (OGTT) to determine glucose tolerance and insulin sensitivity (Cederholm index). Fat oxidation was measured following the OGTT using indirect calorimetry. There was no effect for condition on plasma [glucose] and [insulin] area under the curve (AUC) responses following the OGTT (P > 0.09). However, there was a “trend” for a condition effect for insulin sensitivity with a small increase after HIIE (P = 0.04, ES = 0.28, 9.7%) and MIE (P = 0.07, ES = 0.21, 6.5%) compared to CON. There was an increase in fat oxidation AUC following HIIE (P = 0.008, ES = 0.79, 38.9%) compared to CON, but with no differences between MIE and CON and HIIE and MIE (P > 0.13). In conclusion, 7- to 10-year-old boys may have limited scope to improve insulin sensitivity and glucose tolerance after a single bout of HIIE and MIE. However, fat oxidation is augmented after HIIE but not MIE.