有氧运动训练对老年小鼠骨骼肌抗氧化酶活性的影响

研究长期有氧运动对小鼠骨骼肌抗氧化酶活性的影响。以C57BI。／6J雄性小鼠跑转笼为运动方式。通过分光光度法测定抗氧化酶MnSOD,GSH-Px活性及脂质过氧化产物脂褐素和MDA含量。结果发现。随着年龄的增加,脂质过氧化程度加重,MnSOD活性在衰老初期有升高但后期显降低,而有氧运动训练可明显降低衰老初期骨髂肌线粒体内脂褐素含量,提高GSH-Px活性。这提示长期有规律的适量运动训练在一定程度上能增强骨骼肌的氧化应激,诱导增强抗氧化能力,对延缓衰老有一定意义。     

Effects of plyometric vs. resistance training on skeletal muscle hypertrophy: A review

ObjectiveIn this review, we critically evaluate studies directly comparing the effects of plyometric vs. resistance training on skeletal muscle hypertrophy.MethodsWe conducted electronic searches of PubMed/MEDLINE, Scopus, SPORTDiscus, and Web of Science to find studies that explored the effects of plyometric vs. resistance training on muscle hypertrophy.ResultsEight relevant studies were included in the review. Six studies compared the effects of plyometric vs. resistance training on muscle hypertrophy, while 2 studies explored the effects of combining plyometric and resistance training vs. isolated resistance training on acute anabolic signaling or muscle hypertrophy. Based on the results of these studies, we conclude that plyometric and resistance training may produce similar effects on whole muscle hypertrophy for the muscle groups of the lower extremities. Therefore, it seems that plyometric training has a greater potential for inducing increases in muscle size than previously thought. Despite the findings observed at the whole muscle level, the evidence for the effects of plyometric training on hypertrophy on the muscle fiber level is currently limited for drawing inferences. Compared to isolated resistance training, combining plyometric and resistance exercise does not seem to produce additive effects on anabolic signaling or muscle growth; however, this area requires future study. The limitations of the current body of evidence are that the findings are specific to (a) musculature of the lower extremities, (b) short-term training interventions that lasted up to 12 weeks, and (c) previously untrained or recreationally active participants.ConclusionThis review highlights that plyometric and resistance training interventions may produce similar effects on whole muscle hypertrophy, at least for the muscle groups of the lower extremities, in untrained and recreationally trained individuals, and over short-term (i.e., ≤12 weeks) intervention periods.     

Protective effects of therapeutic cold and heat against the oxidative damage induced by a muscle strain injury in rats

Abstract

The mechanisms of action of physical agents commonly used to treat skeletal muscle lesions are not well understood. In this study, we examined whether the modulation of oxidative stress is involved in the beneficial effects of cold and heat on gastrocnemius muscle strain injury. Adult male Wistar rats were submitted to a strain injury and treated with therapeutic agents in an isolated or combined form. Strain damage caused an increase in muscle and blood oxidative damage. We suggest that this oxidative damage might be related to the impairment of the muscle cell structure, since we observed a significant positive correlation between increased plasma creatine kinase activity and both oxidized dichlorofluoresceine and lipid peroxidation levels in muscle and blood. The intensity of the inflammatory response appears also to be an important factor in the genesis of oxidative damage immediately following a muscle strain injury. Therapeutic cold seems to be more effective in preventing the damage induced by a strain injury, possibly due to its capacity to control the impairment of muscle cell structure and to modulate the intensity of the inflammatory response that follows a muscle strain injury.     

Physical activity and obese children

Childhood obesity is an epidemic of global proportions, accompanied by an alarming increase in various metabolic disorders. It would appear that childhood obesity stems largely from excessive energy intake and that it is the ensuing obesity that leads to physical inactivity in children, as opposed to initial physical inactivity inducing obesity. How changes in body composition that accompany obesity influence physical activity (PA) and the mechanistic basis for this remains poorly understood. This review provides an overview of the PA habits and body composition of the obese children. We suggest skeletal muscle metabolism as a key driver of PA. The role both quantitative and qualitative changes in skeletal muscle may play in oxidative metabolism in the obese children are discussed. There is a real need for research examining the mechanistic basis of physical inactivity in the obese. The dearth of information on the role of skeletal muscle metabolism in the PA of obese youngsters and the emergence of new technologies allowing cellular and metabolite mechanisms to be explored provides plenty of scope for future work.     

Muscle capacity and physical function in older women: What are the impacts of resistance training?

The number of older adults (individuals ≥65 years), particularly women, in our society is increasing and understanding the impact of exercise on muscle capacity (e.g., strength and power) and subsequently physical function is of utmost importance to prevent disability and maintain independence. Muscle capacity declines with age and this change negatively impacts physical function in older women. Exercise, specifically resistance training, is recommended to counteract these declines; however, the synergistic relationships between exercise, muscle capacity, and physical function are poorly understood. This review will summarize the literature regarding age-related changes in the aforementioned variables and review the research on the impact of resistance training interventions on muscle capacity and physical function in older women. Recommendations for future research in this area will be discussed.     

Impact of Overt and Subclinical Hypothyroidism on Exercise Tolerance: A Systematic Review

Purpose: This systematic review describes the state of the art of the impact of hypothyroidism on exercise tolerance and physical performance capacity in untreated and treated patients with hypothyroidism. Method: A systematic computer-aided search was conducted using biomedical databases. Relevant studies in English, German, and Dutch, published from the earliest date of each database up to December 2012, were identified. Results: Out of 116 studies, a total of 38 studies with 1,379 patients fulfilled the inclusion criteria. These studies emphasize the multifactorial causes of exercise intolerance in untreated patients by the impact of limitations in different functional systems, with cardiovascular, cardiopulmonary, musculoskeletal, neuromuscular, and cellular metabolic systems acting in concert. Moreover, the studies affirm that exercise intolerance in patients is not always reversible during adequate hormone replacement therapy. As a consequence, despite a defined euthyroid status, there remains a significant group of treated patients with persistent complaints related to exercise intolerance who are suffering from limitations in daily and sport activities, as well as an impaired quality of life. An explanation for this phenomenon is lacking. Only 2 studies investigated the effects of a physical training program, and they showed inconsistent effects on the performance capacity in untreated patients with subclinical hypothyroidism. Conclusions: A limited body of knowledge exists concerning exercise tolerance in treated patients with hypothyroidism, and there is an insufficient amount of quantitative studies on the effects of a physical training program. To enhance exercise and sports participation for this specific group, more research in this forgotten area is warranted.     

运动训练中补充抗氧化剂：有益还是有害？

运动过程中骨骼肌产生的高水平反应物会导致肌肉损伤和肌肉功能受损，一般认为补充抗氧化剂可以保护肌肉不受损伤。无论对于运动爱好者还是专业运动员，抗氧化剂都是最常用的运动补剂之一。目前备受关注的是用额外口服抗氧化剂的方法来支持内源性防御系统，从而实现预防或减轻氧化应激、减少肌肉损伤并改善运动表现。目前有大量已发表的研究对该主题进行了讨论，大多数研究表明，抗氧化剂可以减轻运动引起的氧化应激，但大多数研究都未发现其对肌肉损伤和肌肉功能有任何影响。此外，越来越多的证据表明，抗氧化剂对健康和训练适应有消极作用。本文深入分析总结了关于活性物质（Reactive Species）在体内的作用以及服用抗氧化剂对维持健康和提高身体性能的功效的文献。     

Strength,power, and postural control in seniors: Considerations for functional adaptations and for fall prevention

Abstract

The ageing neuromuscular system is affected by structural and functional changes that lead to a general slowing down of neuromuscular performance and an increased risk of falling. As a consequence, the process of ageing results in a reduced ability to develop maximal and explosive force, as well as in deficits in static and dynamic postural control. A decrease in the number and size of type II fibres in particular accounts for the age-related decline in muscle mass (sarcopaenia) and strength performance. Multiple denervation and re-innervation processes of muscle fibres seem to be responsible for the reduced number of muscle fibres. Recently, it has been suggested that it is not the decline in motoneurons that accounts for the loss in number of muscle fibres but the disturbed potential of fibre regeneration and re-innervation. Furthermore, an age-related reduction in the number of satellite cells has also been associated with sarcopaenia. The ability to compensate for platform and gait perturbations deteriorates with ageing as reflected in longer onset latencies and inefficient postural responses. All sites within the somatosensory system are affected by ageing and therefore contribute to postural instability. However, morphological changes of muscle spindles appear primarily to be responsible for the impaired ability to compensate for balance threats in old age. Given these neuromuscular limitations in old age, it is important to apply adequate training interventions that delay or even reverse the onset of these constraints. Strength training has the potential to enhance maximal as well as explosive force production capacity. This is accomplished by neural factors, including an improved recruitment pattern, discharge rate, and synchronization of motor units. Furthermore, an increase in number of satellite cells most likely accounts for training-induced muscle hypertrophy. Recent studies have investigated the impact of balance training in old age on the ability to develop maximal and explosive force. In addition, the effects of balance training on reflex activity during gait perturbations were also examined. Increases in maximal and explosive force production capacity and an improved ability to compensate for gait perturbations were observed. It is evident from the literature that researchers are increasingly studying the effects of more specifically designed training programmes on performance in populations of older adults. Thus, in the near future, strength training could be replaced by high-velocity forms of power training and balance training by perturbation-based training programmes. It is hypothesized that this new approach is more efficient in terms of fall prevention than the traditional approach.     

Social isolation and physical inactivity in older US adults: Results from the Third National Health and Nutrition Examination Survey

Abstract

Physical inactivity is a risk factor for cardiovascular and other chronic diseases. It has been shown that both physical inactivity and social isolation increase with age, and that these factors are detrimental to physical and mental well-being. The purpose of the present study was to examine the relationship between physical inactivity and social isolation in older US adults. Using data from a nationally representative cross-sectional survey, the Third National Health and Nutrition Examination Survey, 1988–1994, we assessed the age- and race-specific prevalence of no leisure-time physical activity in relation to various forms of social interaction. The prevalence of no leisure-time physical activity increases with age in both men and women. In non-Hispanic whites, non-Hispanic blacks, and Mexican Americans, the prevalence of no leisure-time physical activity is increased in older US adults who are socially isolated. Social isolation is related to physical inactivity among persons 60 years and older. Longitudinal and intervention studies are needed to establish whether increased social support translates to a more active population of older adults.     

Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis

Purpose:We aimed to perform a systematic review and meta-analysis of the effects of training to muscle failure or non-failure on muscular strength and hypertrophy.Methods:Meta-analyses of effect sizes(ESs)explored the effects of training to failure vs.non-failure on strength and hypertrophy.Subgroup meta-analyses explored potential moderating effects of variables such as training status(trained vs.untrained),training volume(volume equated vs.volume non-equated),body region(upper vs.lower),exercise selection(multi-vs.single-joint exercises(only for strength)),and study design(independent vs.dependent groups).Results:Fifteen studies were included in the review.All studies included young adults as participants.Meta-analysis indicated no significant difference between the training conditions for muscular strength(ES=-0.09,95%confidence interval(95%CI):-0.22 to 0.05)and for hypertrophy(ES=0.22,95%CI:-0.11 to 0.55).Subgroup analyses that stratified the studies according to body region,exercise selection,or study design showed no significant differences between training conditions.In studies that did not equate training volume between the groups,the analysis showed significant favoring of non-failure training on strength gains(ES=-0.32,95%CI:-0.57 to-0.07).In the subgroup analysis for resistance-trained individuals,the analysis showed a significant effect of training to failure for muscle hypertrophy(ES=0.15,95%CI:0.03-0.26).Conclusion:Training to muscle failure does not seem to be required for gains in strength and muscle size.However,training in this manner does not seem to have detrimental effects on these adaptations,either.More studies should be conducted among older adults and highly trained individuals to improve the generalizability of these findings.     

The effects of plyometric jump training on physical fitness attributes in basketball players: A meta-analysis

BackgroundThere is a growing body of experimental evidence examining the effects of plyometric jump training (PJT) on physical fitness attributes in basketball players; however, this evidence has not yet been comprehensively and systematically aggregated. Therefore, our objective was to meta-analyze the effects of PJT on physical fitness attributes in basketball players, in comparison to a control condition.MethodsA systematic literature search was conducted in the databases PubMed, Web of Science, and Scopus, up to July 2020. Peer-reviewed controlled trials with baseline and follow-up measurements investigating the effects of PJT on physical fitness attributes (muscle power, i.e., jumping performance, linear sprint speed, change-of-direction speed, balance, and muscle strength) in basketball players, with no restrictions on their playing level, sex, or age. Hedge's g effect sizes (ES) were calculated for physical fitness variables. Using a random-effects model, potential sources of heterogeneity were selected, including subgroup analyses (age, sex, body mass, and height) and single training factor analysis (program duration, training frequency, and total number of training sessions). Computation of meta-regression was also performed.ResultsThirty-two studies were included, involving 818 total basketball players. Significant (p < 0.05) small-to-large effects of PJT were evident on vertical jump power (ES = 0.45), countermovement jump height with (ES = 1.24) and without arm swing (ES = 0.88), squat jump height (ES = 0.80), drop jump height (ES = 0.53), horizontal jump distance (ES = 0.65), linear sprint time across distances ≤10 m (ES = 1.67) and >10 m (ES = 0.92), change-of-direction performance time across distances ≤40 m (ES = 1.15) and >40 m (ES = 1.02), dynamic (ES = 1.16) and static balance (ES = 1.48), and maximal strength (ES = 0.57). The meta-regression revealed that training duration, training frequency, and total number of sessions completed did not predict the effects of PJT on physical fitness attributes. Subgroup analysis indicated greater improvements in older compared to younger players in horizontal jump distance (>17.15 years, ES = 2.11; ≤17.15 years, ES = 0.10; p < 0.001), linear sprint time >10 m (>16.3 years, ES = 1.83; ≤16.3 years, ES = 0.36; p = 0.010), and change-of-direction performance time ≤40 m (>16.3 years, ES = 1.65; ≤16.3 years, ES = 0.75; p = 0.005). Greater increases in horizontal jump distance were apparent with >2 compared with ≤2 weekly PJT sessions (ES = 2.12 and ES = 0.39, respectively; p < 0.001).ConclusionData from 32 studies (28 of which demonstrate moderate-to-high methodological quality) indicate PJT improves muscle power, linear sprint speed, change-of-direction speed, balance, and muscle strength in basketball players independent of sex, age, or PJT program variables. However, the beneficial effects of PJT as measured by horizontal jump distance, linear sprint time >10 m, and change-of-direction performance time ≤40 m, appear to be more evident among older basketball players.     

Effects of different types of exercise on muscle mass,strength, function and well-being in elderly

Abstract

Poor muscle strength and physical function have been associated with higher risk of hospitalisation and lower well-being among the elderly. Physical training increases muscle strength, endurance and physical function as well as psychological outcomes. Exercise among older adults is often used to improve these variables, but few have compared the effects of different types of training in parallel independent groups. Thus, the aim of the present study was to investigate the effect of three different types of training on body composition, muscle strength, physical function and well-being in the elderly. A total of 118 community-dwelling older adults (mean age 74.3, s=4.6 years, 68% women) completed a 13-week randomised controlled exercise-trial involving four groups: traditional strength training (STG), functional strength training (FTG), endurance training (ETG) and control (CON). Stair climb with load improved more in FTG than CON (P<0.05), and the two strength groups performed better in the functional upper body test (P<0.05). STG increased strength more than CON in all exercises (P<0.001), while FTG increased strength more than CON in the chest press, shoulder press and knee extension (P<0.05). Lean body mass (LBM) increased in all training groups, which differed significantly from CON (P<0.05). ETG decreased their fat mass compared to CON (P<0.001). The only significant effect on well-being indices was improved life satisfaction in FTG at week 5 (P<0.05). We also observed significant correlations between change in some of the functional tests and change in positive affect.

All three types of training can enhance physical capacity. Functional strength training can be a cost effective form of training in terms of less demand for instructors and equipment and could be an effective way to improve physical function, strength and indices of well-being in the elderly.     

肌组织对耐力性运动适应能力的生理学分析

在耐力性运动中,有氧代谢是机体能量供应的1种主要方式,肌组织对有氧训练的适应能力是通过训练中肌肉的主动性运动而获取的。这些适应能力依靠运动训练的持续性而存在或发展;随运动训练的停止而减弱或消退。本文就肌纤维的类型、线粒体的含量、毛细血管的分布、血流量等方面分析了耐力性运动中肌组织在有氧代谢过程中所产生的适应性变化的机制以及运动强度和持续时间等外界因素对这种生理变化过程的影响。     

体育教学中防控近视的睫状肌训练频次研究

目的： 分析比较体育教学中低频15次、中频30次,以及高频60次的睫状肌训练对八年级学生视力所产生的不同影响方法： 在体育课中分别对3个实验组进行低频15次、中频30次、高频60次睫状肌训练,测量并分析干预前后实验组与对照组学生的裸眼远视力与动态视力结果： (1)低频15次组学生的裸眼远视力与动态视力无显著性变化;(2)中频30次组学生的动态视力在干预后显著上升,裸眼远视力的提高无显著性差异;(3)高频60次组学生的裸眼远视力与动态视力在干预后均显著上升;(4)对照组学生的裸眼远视力与动态视力呈下降趋势结论： 体育教学中嵌入不同频次的睫状肌训练对八年级学生视力水平的影响不同,其中60次高频训练对裸眼远视力改善效果最佳,30次中频训练对动态视力的改善效果更好,15次低频训练能够基本维持学生裸眼远视力和动态视力的原有水平。在体育教学中进行睫状肌训练能够有效延缓近视的发展速度,促进学生视力水平发展。     

减量训练对大鼠骨骼肌超微结构及酶活性的影响

目的探讨大负荷训练后减量训练对大鼠骨骼肌超微结构及其酶活性的影响,为大负荷运动后减量训练的研究提供理论和实验参考。方法大负荷运动7周后,再进行4周减量训练,运用酶免疫和电子显微镜技术观察大负荷训练后减量训练腓肠肌琥珀酸脱氢酶(SDH)、乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)和丙二醛(MDA)表达及腓肠肌超微结构的变化。结果大负荷训练后再进行4周的减量训练,可明显提高SHD活性,降低MDA的含量,但LDH活性降低;4周的减量训练损伤的腓肠肌细胞结构基本恢复正常。结论 4周的减量训练可明显改善损伤的骨骼肌细胞结构,有利于骨骼肌细胞结构的恢复,提高骨骼肌的有氧代谢能力和抗氧化能力,但不能提高骨骼肌的无氧代谢能力。     

Sand training: a review of current research and practical applications

Abstract

Sand surfaces can offer a higher energy cost (EC) and lower impact training stimulus compared with firmer and more traditional team sport training venues such as grass. This review aims to summarise the existing research on sand training, with a specific focus on its application as a team sports training venue. Compared with grass, significant physiological and biomechanical differences are associated with sand exercise. However, evidence also exists to suggest that training adaptations unique to sand can positively influence firm-ground performance. Furthermore, the lower impact forces experienced on sand can limit muscle damage, muscle soreness, and decrements in performance capacity relative to exercise intensity. Therefore, using a sand training surface in team sports may allow greater training adaptations to be achieved, while reducing performance decrements and injuries that may arise from heavy training. Nevertheless, further research should investigate the effect of sand surfaces over a greater range of training types and performance outcomes, to increase the application of sand training for team sports.     

Physical activity lowers the risk for acute respiratory infections: Time for recognition

Physical inactivity is a well-established risk factor for chronic diseases, such as cardiovascular disease, cancer, and diabetes mellitus. There is a growing awareness that physical inactivity should also be regarded as a risk factor for acute respiratory infections (ARIs). ARIs, such as the common cold, influenza, pneumonia, and coronavirus disease 2019 (COVID-19), are among the most pervasive diseases on earth and cause widespread morbidity and mortality. Evidence in support of the linkage between ARIs and physical inactivity has been strengthened during the COVID-19 pandemic because of increased scientific scrutiny. Large-scale studies have consistently reported that the risk for severe COVID-19 outcomes is elevated in cohorts with low physical activity and/or physical fitness, even after adjusting for other risk factors. The lowered risk for severe COVID-19 and other ARIs in physically active groups is attributed to exercise-induced immunoprotective effects, including enhanced surveillance of key immune cells and reduced chronic inflammation. Scientific consensus groups, including those who submitted the Physical Activity Guidelines for Americans, have not yet given this area of research the respect that is due. It is time to add “reduced risk for ARIs” to the “Exercise is Medicine” list of physical activity-related health benefits.     

女子划艇十三运会赛前12周训练负荷结构特征分析

运用文献资料法、专家访谈法、跟踪测试法、数理统计法,对江西女子划艇队夺冠成员在2017年天津全运赛前12周训练负荷结构特征进行分析,为总结高龄运动员的训练模式特征提供实证依据。结论:女划运动员在第一阶段以恢复、提升运动员的基础体能为重点;第二阶段以巩固、提升有氧能力和强化水上专项能力进行训练实施。训练的总量趋势大体呈先增量后减量;越临近比赛,水上训练量逐步增加,陆上训练量逐渐减少。江西女划队以有氧训练为主,有氧训练所占的比列最高;水上抗阻训练比例和水上速度训练比例相当;SKM训练类型的训练比例最低,模拟比赛训练的比例仅高于SKM训练类型。陆上机能训练中大力量训练比例最高;力量耐力次之;陆上有氧训练再次之,其中,自身负重和核心训练是调节性训练,比例较低。此外,江西女划队特别注重运动员的机能恢复训练。