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1.
人体内脂肪酸(FFA)与糖相比具有贮量大、单位质量贮能高等特点,是长时间运动的理想能源。研究认为有氧训练可以提高骨骼肌对脂肪的氧化能力,但有关脂肪的研究远没有对糖的研究那样深入与广泛。结合近来的有关脂肪代谢的研究成果从脂肪组织的脂解和FFA的运输、FFA跨肌肉细胞膜的运转、FFA跨线粒体膜的运转、肌肉中甘油三酯(IMTG)的动用4个方面作几点探讨,旨在对运动与脂肪代谢的研究做一点贡献。  相似文献   

2.
运动时骨骼肌两种重要能源底物,碳水化合物和脂肪在氧化供能时存在交互关系,且与G-FA循环理论以外的机制有关。运动中增加脂肪的可用性可降低骨骼肌PDH活性,减少肌糖原分解,可能是通过增加线粒体NADH可用性,进而缓解运动诱导的游离ADP,AMP和Pi累积增加;增加外源性CHO可用性能减少骨骼肌脂肪氧化,可能是通过血浆胰岛素水平增加和FFA可用性下降,也可能是通过减少脂肪转运进入肌肉和/或降低线粒体速率等机制;运动强度增加机体更依赖于CHO供能,可能通过肌肉内、外机制下调脂肪代谢。  相似文献   

3.
“Crossover”概念可以解释耐力项目运动中,运动强度和耐力训练对糖、脂肪代谢平衡的影响。根据“Crossover”的概念:耐力训练引起肌肉的生化适应,增加脂肪的氧化供能。小强度运动(≤45% VO2 m ax)以脂肪供能为主,大强度运动(~75% VO2 m ax)糖是主要供能底物,即便是经过耐力训练也不例外。  相似文献   

4.
脂肪在人体内的贮存量比糖丰富,但机体氧化脂肪酸的能力有限,限制利用贮存脂肪的原因至今尚未完全阐明.线粒体脂肪氧化作为脂肪代谢的限速步骤,从许多方面影响机体FA氧化,如线粒体肉碱酰基转移酶(CPT)系统、多种线粒体膜结合蛋白、磷酸腺苷活化蛋白激酶(AMPK),运动对其影响的研究结果不一.在此综述骨骼肌线粒体脂肪氧化对脂肪代谢的作用以及运动对其的影响.  相似文献   

5.
脂肪在运动时的供能作用一直是一个有争论的问题。近几年来由于放射性同位素技术在运动生化领域中的应用,才逐渐认识到运动时脂肪的重要供能作用,纠正了以往认为糖是肌肉运动时唯一供能物质的片面认识。同时,近年来又发现,有规律的体力运动对预防和抑制缺血性心脏病和动脉粥样硬化的形成和发展具有重要的作用,因而运动和脂肪代谢成为运动医学领域中的一个重要课题。  相似文献   

6.
运动和脂肪代谢   总被引:1,自引:0,他引:1  
本文综述了国内外有关研究的最新材料,深入阐述了体育运动中脂肪供能的重要性和机制,脂肪代谢同心脏病、高血压病的关系,体育训练对脂肪代谢的影响,值得教练员、医生和科研工作者一阅。主要内容为: 一、人体脂肪的储存和供能形式 二、各类脂类物质在运动时的代谢 三、脂肪动员的机制 四、脂肪供能与糖代谢的关系 五、训练对脂肪代谢的影响  相似文献   

7.
运动与细胞因子的研究进展   总被引:6,自引:2,他引:4  
何伟 《体育科学》2005,25(7):63-67,83
运动期间血浆细胞因子主要来源于收缩的骨骼肌和脂肪组织,尤其是IL-6。运动时糖和脂肪的代谢与IL-6有关,IL-6也可能参与肌纤维溶解和肌肉萎缩。IL-15可能介导力量训练所致的肌肉壮大。免疫细胞不是运动中血浆细胞因子的主要来源。  相似文献   

8.
补糖对不同时间运动后小鼠酮体代谢的影响   总被引:3,自引:0,他引:3  
将昆明种4~6周龄雄性小白鼠随机分为补糖和补水对照组。每组均设安静组、定量运动组和力竭运动组。补糖采用浓度为5%葡萄糖与7%低聚糖的混合溶液。定量运动组做一次性静水负重游泳运动,持续时间为1h。力竭组与定量组运动形式相同,运动时间至力竭。分别测定血液、肝脏、骨骼肌和脑中的酮体(Ketone Body,KB),肝、骨骼肌糖原以及血糖、脑糖、血清游离脂肪酸(FFA)等指标。结果显示:与补糖组相比,1h游泳运动后补水组血清FFA有升高趋势,但无显著性差异,补水组小鼠血酮体浓度显著升高(P<0.05);力竭运动后补水组骨骼肌、肝脏中酮体含量显著高于补糖组(P<0.05)。提示:小鼠机体糖状况直接影响运动中的酮体代谢,运动性酮体代谢与体内糖储备以及脂肪分解状况有关。  相似文献   

9.
研究大强度运动过程中成纤维细胞生长因子21(FGF21)对糖、脂代谢关联物生长激素(GH)、血清游离脂肪酸(FFA)、β羟丁酸、胰岛素(Insulin)及血糖(Glucose)的影响,同时对运动锻炼后不同时刻FGF21与上述指标变化的相关性进行探讨,以期阐明大强度运动过程中FGF21与糖、脂代谢关联物的变化规律。  相似文献   

10.
膳食脂肪对运动能力的影响及运动时脂代谢的调节   总被引:1,自引:0,他引:1  
陈梅 《体育学刊》2004,11(6):49-51
就膳食脂肪对运动能力的影响以及脂肪代谢的调节作一综述。运动强度、时间不同,脂肪供能所占的比例不同,脂肪供能对运动成绩的影响也有所差异。运动时脂代谢的调节受多种因素的影响,激素敏感性甘油三酯脂肪酶(HSL)是酶解速度的主要控制因素。  相似文献   

11.
Carbohydrate ingestion before and during endurance exercise delays the onset of fatigue (reduced power output). Therefore, endurance athletes are recommended to ingest diets high in carbohydrate (70% of total energy) during competition and training. However, increasing the availability of plasma free fatty acids has been shown to slow the rate of muscle and liver glycogen depletion by promoting the utilization of fat. Ingested fat, in the form of long-chain (C 16-22 ) triacylglycerols, is largely unavailable during acute exercise, but medium-chain (C 8-10 ) triacylglycerols are rapidly absorbed and oxidized. We have shown that the ingestion of medium-chain triacylglycerols in combination with carbohydrate spares muscle carbohydrate stores during 2 h of submaximal (< 70% VO 2 peak) cycling exercise, and improves 40 km time-trial performance. These data suggest that by combining carbohydrate and medium-chain triacylglycerols as a pre-exercise supplement and as a nutritional supplement during exercise, fat oxidation will be enhanced, and endogenous carbohydrate will be spared. We have also examined the chronic metabolic adaptations and effects on substrate utilization and endurance performance when athletes ingest a diet that is high in fat (> 70% by energy). Dietary fat adaptation for a period of at least 2-4 weeks has resulted in a nearly two-fold increase in resistance to fatigue during prolonged, low- to moderate-intensity cycling (< 70% VO 2 peak). Moreover, preliminary studies suggest that mean cycling 20 km time-trial performance following prolonged submaximal exercise is enhanced by 80 s after dietary fat adaptation and 3 days of carbohydrate loading. Thus the relative contribution of fuel substrate to prolonged endurance activity may be modified by training, pre-exercise feeding, habitual diet, or by artificially altering the hormonal milieu or the availability of circulating fuels. The time course and dose-response of these effects on maximizing the oxidative contribution of fat for exercise metabolism and in exercise performance have not been systematically studied during moderate- to high-intensity exercise in humans.  相似文献   

12.
Soccer players should achieve an energy intake that provides sufficient carbohydrate to fuel the training and competition programme, supplies all nutrient requirements, and allows manipulation of energy or nutrient balance to achieve changes in lean body mass, body fat or growth. Although the traditional culture of soccer has focused on carbohydrate intake for immediate match preparation, top players should adapt their carbohydrate intake on a daily basis to ensure adequate fuel for training and recovery between matches. For players with a mobile playing style, there is sound evidence that dietary programmes that restore and even super-compensate muscle glycogen levels can enhance activity patterns during matches. This will presumably also benefit intensive training, such as twice daily practices. As well as achieving a total intake of carbohydrate commensurate with fuel needs, the everyday diet should promote strategic intake of carbohydrate and protein before and after key training sessions to optimize the adaptations and enhance recovery. The achievement of the ideal physique for soccer is a long-term goal that should be undertaken over successive years, and particularly during the off-season and pre-season. An increase in lean body mass or a decrease in body fat is the product of a targeted training and eating programme. Consultation with a sports nutrition expert can assist soccer players to manipulate energy and nutrient intake to meet such goals. Players should be warned against the accidental or deliberate mismatch of energy intake and energy expenditure, such that energy availability (intake minus the cost of exercise) falls below 125 kJ (30 kcal) per kilogram of fat-free mass per day. Such low energy availability causes disturbances to hormonal, metabolic, and immune function.  相似文献   

13.
肥胖男青年对两种强度有氧运动的生理代谢反应比较   总被引:4,自引:1,他引:3  
目的:分析两种强度有氧运动过程中机体能源物质动员的特点,为制定减肥运动处方提供理论依据。方法:8名无系统运动训练史的非继发性肥胖男青年进行40%和65%V。O2max强度有氧运动,监测运动过程中受试者HR、血压及RPE等生理指标和血清GLU、TG、FFA及GH等生化指标的变化。结果:40%V。O2max有氧运动过程中HR、收缩压、RPE及血清GLU水平显著低于(舒张压显著高于)65%V。O2max有氧运动;血清GH水平有降低趋势;血清TG、FFA水平显著高于65%V。O2max有氧运动。40%V。O2max有氧运动过程中,脂肪动员程度较大,随着运动强度的增加,机体糖代谢加强,脂代谢减弱。结论:肥胖者宜采用40%V。O2max有氧运动进行减肥健身锻炼,不仅能更大程度地动员脂肪供能,而且相对不易疲劳,主观体力感觉也易于接受。  相似文献   

14.
Carbohydrates and fat for training and recovery   总被引:3,自引:0,他引:3  
An important goal of the athlete's everyday diet is to provide the muscle with substrates to fuel the training programme that will achieve optimal adaptation for performance enhancements. In reviewing the scientific literature on post-exercise glycogen storage since 1991, the following guidelines for the training diet are proposed. Athletes should aim to achieve carbohydrate intakes to meet the fuel requirements of their training programme and to optimize restoration of muscle glycogen stores between workouts. General recommendations can be provided, preferably in terms of grams of carbohydrate per kilogram of the athlete's body mass, but should be fine-tuned with individual consideration of total energy needs, specific training needs and feedback from training performance. It is valuable to choose nutrient-rich carbohydrate foods and to add other foods to recovery meals and snacks to provide a good source of protein and other nutrients. These nutrients may assist in other recovery processes and, in the case of protein, may promote additional glycogen recovery when carbohydrate intake is suboptimal or when frequent snacking is not possible. When the period between exercise sessions is < 8 h, the athlete should begin carbohydrate intake as soon as practical after the first workout to maximize the effective recovery time between sessions. There may be some advantages in meeting carbohydrate intake targets as a series of snacks during the early recovery phase, but during longer recovery periods (24 h) the athlete should organize the pattern and timing of carbohydrate-rich meals and snacks according to what is practical and comfortable for their individual situation. Carbohydrate-rich foods with a moderate to high glycaemic index provide a readily available source of carbohydrate for muscle glycogen synthesis, and should be the major carbohydrate choices in recovery meals. Although there is new interest in the recovery of intramuscular triglyceride stores between training sessions, there is no evidence that diets which are high in fat and restricted in carbohydrate enhance training.  相似文献   

15.
An important goal of the athlete's everyday diet is to provide the muscle with substrates to fuel the training programme that will achieve optimal adaptation for performance enhancements. In reviewing the scientific literature on post-exercise glycogen storage since 1991, the following guidelines for the training diet are proposed. Athletes should aim to achieve carbohydrate intakes to meet the fuel requirements of their training programme and to optimize restoration of muscle glycogen stores between workouts. General recommendations can be provided, preferably in terms of grams of carbohydrate per kilogram of the athlete's body mass, but should be fine-tuned with individual consideration of total energy needs, specific training needs and feedback from training performance. It is valuable to choose nutrient-rich carbohydrate foods and to add other foods to recovery meals and snacks to provide a good source of protein and other nutrients. These nutrients may assist in other recovery processes and, in the case of protein, may promote additional glycogen recovery when carbohydrate intake is suboptimal or when frequent snacking is not possible. When the period between exercise sessions is <8?h, the athlete should begin carbohydrate intake as soon as practical after the first workout to maximize the effective recovery time between sessions. There may be some advantages in meeting carbohydrate intake targets as a series of snacks during the early recovery phase, but during longer recovery periods (24?h) the athlete should organize the pattern and timing of carbohydrate-rich meals and snacks according to what is practical and comfortable for their individual situation. Carbohydrate-rich foods with a moderate to high glycaemic index provide a readily available source of carbohydrate for muscle glycogen synthesis, and should be the major carbohydrate choices in recovery meals. Although there is new interest in the recovery of intramuscular triglyceride stores between training sessions, there is no evidence that diets which are high in fat and restricted in carbohydrate enhance training.  相似文献   

16.
Abstract

The increased energy demand that occurs with incremental exercise intensity is met by increases in the oxidation of both endogenous fat and carbohydrate stores up to an intensity of ~70% V˙O2max in trained individuals. However, when exercise intensity increases beyond this workload, fat oxidation rates decline, both from a relative and absolute perspective. As endogenous glycogen use is accelerated, glycogen stores can become depleted, ultimately resulting in fatigue and the inability to maintain high intensity, submaximal exercise (>70% V˙O2max). Despite a considerable accumulation of knowledge that has been gained over the past half century, the precise mechanism(s) regulating muscle fuel selection and underpinning the aforementioned decline in fat oxidation remain largely unclear. A greater understanding would undoubtedly lead to novel strategies to increase fat utilization and, as such, improve exercise capacity. The present review primarily addresses one of the most prominent theories to explain the phenomenon of diminished fat oxidation during high intensity, submaximal exercise; a reduced availability of muscle free carnitine for mitochondrial fat translocation. This is discussed in the light of recent work in this area taking advantage of the discovery that muscle carnitine content can be increased in vivo in humans. Furthermore, the evidence supporting the recently proposed theory that reduced muscle co-enzyme A availability to several key enzymes in the fat oxidation pathway may also exert a degree of control over muscle fuel selection during exercise is also considered. Strong correlational evidence exists that muscle free carnitine availability is likely to be a key limiting factor to fat oxidation during high intensity, submaximal exercise. However, it is concluded that further intervention studies manipulating the muscle carnitine pool in humans are required to establish a direct causal role. In addition, it is concluded that while a depletion of muscle coenzyme A availability during exercise also offers a viable mechanism for impairing fat oxidation, at present, this remains speculative.  相似文献   

17.
Abstract

A key element contributing to deteriorating exercise capacity during physically demanding sport appears to be reduced carbohydrate availability coupled with an inability to effectively utilize alternative lipid fuel sources. Paradoxically, cognitive and physical decline associated with glycogen depletion occurs in the presence of an over-abundance of fuel stored as body fat that the athlete is apparently unable to access effectively. Current fuelling tactics that emphasize high-carbohydrate intakes before and during exercise inhibit fat utilization. The most efficient approach to accelerate the body’s ability to oxidize fat is to lower dietary carbohydrate intake to a level that results in nutritional ketosis (i.e., circulating ketone levels >0.5 mmol/L) while increasing fat intake for a period of several weeks. The coordinated set of metabolic adaptations that ensures proper interorgan fuel supply in the face of low-carbohydrate availability is referred to as keto-adaptation. Beyond simply providing a stable source of fuel for the brain, the major circulating ketone body, beta-hydroxybutyrate, has recently been shown to act as a signalling molecule capable of altering gene expression, eliciting complementary effects of keto-adaptation that could extend human physical and mental performance beyond current expectation. In this paper, we review these new findings and propose that the shift to fatty acids and ketones as primary fuels when dietary carbohydrate is restricted could be of benefit for some athletes.  相似文献   

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