Exercise Speeds Cutaneous Wound Healing in High-Fat Diet-Induced Obese Mice

PURPOSE: Obesity has been shown to impair cutaneous wound healing, which is associated with increased wound inflammation. Exercise is known to decrease obesity-associated inflammation and has been shown to speed cutaneous wound healing in aged mice. Therefore, we investigated whether treadmill exercise could speed cutaneous wound healing in obese, high-fat diet-fed mice. METHODS: We fed female C57Bl/6J mice a high-fat diet (45% calories from fat) for 16 wk to induce a state of obesity and insulin resistance. Mice then ran on a treadmill for 3 d before excisional wounding. On day 4, mice were wounded 1 h after exercise. Mice then exercised for 5 d after wounding, and healing was assessed by photoplanimetry for 10 d. RESULTS: As described previously, obesity impaired wound healing, with significantly larger wound sizes measured from days 3 to day 10 after wounding (P < 0.05). Exercise did not improve healing in lean mice fed a normal chow diet. However, wound size was significantly smaller in exercised obese mice compared with their lean counterparts (P < 0.05 at day 1, day 4, and day 5 after wound). Surprisingly, we were unable to detect any differences in gene or protein expression of proinflammatory cytokines interleukin-1β and tumor necrosis factor-α or the anti-inflammatory cytokine interleukin-10 in the wounds. Likewise, there were no differences in gene expression of chemokines monocyte chemoattractant protein-1 and keratinocyte chemoattractant or of growth factor platelet-derived growth factor in wounds of exercise and sedentary mice. CONCLUSION: This suggests an effect of exercise independent of alterations in inflammation. Future work should focus on early events after wounding, including exercise effects on hemostasis and myofibroblast function.     

有氧运动和膳食脂肪对ApoE基因缺陷小鼠动脉粥样硬化斑块形成的影响

为了探讨有氧运动和膳食因素在动脉粥样硬化斑块形成过程中的作用,研究了在跑台上进行的有氧运动和低脂膳食对ApoE基因缺陷小鼠动脉粥样硬化斑块形成过程的影响。结果表明10周中等强度的有氧运动组和低脂膳食组ApoE基因缺陷小鼠主动脉窦处形成的动脉粥样硬化斑块面积均较对照组减少（P<0.05）;有氧运动结合低脂膳食组ApoE基因缺陷小鼠的斑块面积分别低于单独的运动组和低脂膳食组（P<0.05）。研究提示有氧运动和低脂膳食均有利于并有效减轻动脉粥样硬化斑块的形成,有氧运动和低脂膳食两种因素结合的作用大于单独的有氧运动和低脂膳食的作用,二者在预防动脉粥样硬化斑块的形成上可能存在协同加强作用。     

Effects of creatine supplementation on body composition and renal function in rats

BACKGROUND: The aim of the present study was to evaluate the long-term effects of oral creatine supplementation on renal function and body composition (fat and lean mass) in an experimental model. METHODS: Male Wistar rats were supplemented with creatine (2 g.kg(-1) of food) for 10 wk in combination with treadmill exercise, 12 m.min(-1), 1 h.d(-1) (CREAT + EX, N = 12) or not (CREAT, N = 10), and compared with exercised animals without creatine supplementation (EX, N = 7) and CONTROL animals, N = 7. Body composition and bone mineral density (BMD) were determined by dual x-ray absorptiometry and glomerular filtration rate (GFR) and renal plasma flow (RPF) were measured by inulin and paraaminohippurate clearance, respectively. RESULTS: At the end of the study (post), CREAT+EX presented higher lean mass and lower fat mass than CREAT, EX or CONTROL (349.7 +/- 19.7 vs 313.3 +/- 20.3, 311.9 +/- 30.8, 312.4 +/- 21.0 g and 5.7 +/- 2.3 vs 10.0 +/- 3.3, 9.8 +/- 1.5, 10.0 +/- 3.5%, P < 0.05, respectively). Post lean/fat mass ratio was higher than baseline only in CREAT + EX (18.9 +/- 7.2 vs 8.6 +/- 1.8, P < 0.05). Post BMD was significantly higher than baseline in all groups. GFR and RPF were lower in CREAT versus CONTROL (0.5 +/- 0.1 vs 1.0 +/- 0.1 and 1.5 +/- 0.2 vs 2.4 +/- 0.5 mL.min(-1), P < 0.05, respectively). CONCLUSION: Creatine supplement in combination with exercise increased the proportion of lean mass more than EX or CREAT alone. The use of creatine alone induced an important and significant reduction of both RPF and GFR.     

Oral quercetin supplementation hampers skeletal muscle adaptations in response to exercise training

We aimed to test exercise‐induced adaptations on skeletal muscle when quercetin is supplemented. Four groups of rats were tested: quercetin sedentary, quercetin exercised, placebo sedentary, and placebo exercised. Treadmill exercise training took place 5 days a week for 6 weeks. Quercetin groups were supplemented with quercetin, via gavage, on alternate days throughout the experimental period. Sirtuin 1 (SIRT1), peroxisome proliferator‐activated receptor γ coactivator‐1α mRNA levels, mitochondrial DNA (mtDNA) content, and citrate synthase (CS) activity were measured on quadriceps muscle. Redox status was also quantified by measuring muscle antioxidant enzymatic activity and oxidative damage product, such as protein carbonyl content (PCC). Quercetin supplementation increased oxidative damage in both exercised and sedentary rats by inducing higher amounts of PCC (P < 0.001). Quercetin supplementation caused higher catalase (P < 0.001) and superoxide dismutase (P < 0.05) activity in the non‐exercised animals, but not when quercetin is supplemented during exercise. Quercetin supplementation increased SIRT1 expression, but when quercetin is supplemented during exercise, this effect is abolished (P < 0.001). The combination of exercise and quercetin supplementation caused lower (P < 0.05) mtDNA content and CS activity when compared with exercise alone. Quercetin supplementation during exercise provides a disadvantage to exercise‐induced muscle adaptations.     

Exercise training in obesity lowers blood pressure independent of weight change

PURPOSE: We used the rabbit model of obesity and exercise training to determine effects of exercise training during the development of obesity on resting blood pressure and heart rate, ventricular hypertrophy, blood volume, and hormonal profile. METHODS: Female New Zealand white rabbits were assigned to one of four groups: lean sedentary (L-S, N = 17), lean exercise-trained (L-EX, N = 16), obese sedentary (O-S, N = 18), and obese exercise-trained (O-EX, N = 15). Lean rabbits were fed a maintenance diet whereas obese rabbits were fed an ad libitum high fat (10% added fat) diet. Simultaneously, exercise-trained animals underwent a progressive treadmill exercise training protocol for 12 wk. After 12 wk of diet and exercise regimens, resting blood pressure and heart rate were measured from a central ear artery catheter. Ventricular hypertrophy was evaluated using wet ventricular weights. Blood volume was measured using the Evans blue dye procedure; hormonal profile was evaluated from arterial plasma/serum samples. RESULTS: After 12 wk, O-S and O-EX had similar body weights and similar percentage increases in body weight. Despite similar body weights, O-EX had an approximate 6-mm Hg lower mean blood pressure compared with the elevated pressure seen in O-S (P < or = 0.05). Obese rabbits had greater resting heart rate, plasma cholesterol and triglycerides, and plasma renin activity compared with lean rabbits, and these values were unaffected by exercise training. Plasma and blood volumes, as well as plasma insulin, cortisol, and aldosterone were unaffected by exercise training. CONCLUSION: These data suggest that exercise training, in the absence of differences in body weight, may be useful in the reduction of obesity-induced hypertension but that other therapies may be needed in order to control other cardiovascular risk factors.     

Cumulative effects of conjugated linoleic acid and exercise on endurance development, body composition, serum leptin and insulin levels

AIM: The aim of this study was to evaluate the accruing effects of conjugated linoleic acid (CLA) supplementation and aerobic exercise (Ex) on body composition and serum lipid profile in humans. METHODS: Forty-four healthy female young subjects were divided ExCLA, CLA, Ex and control (C) groups. The groups of CLA and ExCLA were supplemented with 3.6 g/d CLA whilst ExCLA and Ex groups were exercised for 30 min(-1.)3 days(-1.)week(-1) for 6 weeks. RESULTS: After the study period, fat ratio, fat mass, waist and hip girths were reduced in all experimental groups and fat-free mass induced in ExCLA and CLA groups and body weight was reduced in the CLA group when compared to baseline levels. These alterations were significantly different than those of controls with the highest variations were observed in the ExCLA. There was no change in serum leptin, apo-AI, apo-B, total cholesterol, HDL, LDL, free fatty acid, and triglyceride levels. Serum glucose concentrations of ExCLA and CLA groups and insulin level of ExCLA group decreased significantly as compared to baseline levels with only serum glucose reduction of both groups were significantly different than those of controls (P<0.05). Endurance performance significantly increased in ExCLA and Ex groups (P<0.01) but did not vary in the CLA and controls. CONCLUSIONS: It was shown that both CLA and exercise were effective in improvement of body composition and these effects were cumulated when they have been used together. CLA supplementation alone or with exercise seems effective on serum glucose and insulin concentrations but ineffective on endurance performance.     

Motives and barriers to initiation and sustained exercise adherence in a fitness club setting—A one-year follow-up study

No prospective studies have investigated motives and barriers to exercise in new untrained fitness club members. The aims of the present prospective longitudinal study were to (a) examine proportions reporting regular exercise, non-regular exercise, and exercise dropout; (b) identify motives and barriers to exercise; and (c) compare motives between regular and non-regular exercisers the first year of fitness club membership. New members (n = 250) were followed for 1 year. A questionnaire including demographics, exercise frequency, motives (EMI-2), and barriers (18 common reported barriers) was used, and 184 answered at four time points (onset, and after 3, 6, and 12 months). Participants were categorized into regular exercise: ≥2 sessions/wk or non-regular exercise: ≤1 session/wk, exercise relapse, or dropout. At 3, 6, and 12 months, 63.4%, 59.6%, and 57.2% exercised regularly, whereas 20.1%, 21.1%, and 28.3%, dropped out, respectively. Throughout the follow-up, 37% reported regular exercise. At all time points, motives regarding positive health and strength/endurance were rated highest on a six-point scale. Exercise dropouts rated priority as the greatest barrier. Regular exercisers rated the motives enjoyment (such as “I enjoy the feeling of exerting myself”) and challenge (such as “To give me goals to work towards”) higher than non-regular exercisers (P = ≤.05). In conclusion, less than half exercised regularly, and most members were motivated by factors such as positive health and physical fitness the first year of fitness club membership. Higher levels of the motives enjoyment and challenge were associated with regular exercise.     

运动、锌铜营养与自由基代谢——Ⅵ.不同量锌补充对缺锌运动小鼠体内自由基生成与清除的影响

离乳Balb/c小鼠64只,按性别体重随机分成继续缺锌、缺锌后补锌5ppm、缺锌后补锌50ppm及缺锌后补锌500ppm四大组,每大组又分成运动和不运动两组。开始时所有小鼠均进食缺锌饲料。6周后继续缺锌组小鼠继续进食缺锌饲料,其余各组则分别进食补锌5、50和500ppm的补锌饲料。又3周后,所有小鼠均处死并取血、肝进行锌、铜、丙二醛(MDA)、超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GSH-Px) 的测定。结果提示:补锌50ppm对运动及不运动缺锌小鼠各项指标的恢复均有良好作用;补锌5ppm对运动小鼠非最佳剂量。补锌500ppm无论对运动小鼠还是不运动小鼠均有害。     

Effect of endurance training supplemented with green tea extract on substrate metabolism during exercise in humans

Endurance training and ingestion of green tea extract (GTE), composed mainly of tea catechins (TC), are well known to enhance fat metabolism. However, their synergistic effects remain to be fully elucidated. We tested the hypothesis that endurance training supplemented with GTE would further accelerate whole‐body fat utilization during exercise, compared with training alone, in humans. Twelve healthy male subjects [peak oxygen consumption (), 50.7 ± 1.3 (SEM) mL/kg/min] were divided into two groups: GTE and placebo (PLA) groups. Subjects in both groups performed a cycle ergometer exercise at 60% of for 60 min/day, 3 days/week, and daily ingested 572.8 or 0 mg TC in GTE and PLA groups for 10 weeks, respectively. Before and after training, respiratory gas exchange was measured during 90‐min exercise at pre‐training ～55% of . After training, the average respiratory exchange ratio during exercise remained unchanged in the PLA group (post‐training: 0.834 ± 0.008 vs pre‐training: 0.841 ± 0.004), whereas it was lower in the GTE group (post‐training: 0.816 ± 0.006 vs pre‐training: 0.844 ± 0.005, P<0.05). These results suggest that habitual GTE ingestion, in combination with moderate‐intense exercise, was beneficial to increase the proportion of whole‐body fat utilization during exercise.     

有氧运动改善高脂膳食诱导的胰岛素抵抗:增强骨骼肌线粒体融合与分裂及功能

目的:研究高脂膳食诱导胰岛素抵抗(IR)发生中骨骼肌线粒体融合与分裂的改变和长期耐力训练对其影响,为深入探讨IR发生的分子病理学机制以及运动防治IR的机制提供依据。方法:雄性C57BL/6小鼠通过8周高脂膳食诱导IR,再分别将正常和IR小鼠分为安静组和运动组,即正常膳食对照组(NS)、正常膳食运动组(NE)、高脂膳食对照组(HS)、高脂膳食运动组(HE),各运动组进行8周有氧运动训练。检测空腹血糖、胰岛素。提取骨骼肌线粒体测定呼吸功能和ATP合成酶活力。实时荧光定量PCR和Western blot分别测定骨骼肌Mfn2、Opa1、Drp1、Fis1的mRNA和蛋白表达。结果:(1)HS组小鼠空腹血糖、胰岛素和胰岛素抵抗指数均显著高于NS组(P<0.01);骨骼肌线粒体态3呼吸速率、呼吸控制比和ATP酶合成活力均显著低于NS组(P<0.01);Mfn2蛋白显著低于NS组(P<0.01),Drp1和Fis1显著高于NS组(P<0.01)。(2)HE组小鼠空腹血糖、胰岛素和胰岛素抵抗指数均显著高于HS组(P<0.01);骨骼肌线粒体态3呼吸速率、RCR和ATP酶合成活力均显著高于HS组(P<0.01);Mfn2、Opa1和Drp1蛋白显著高于HS组(P<0.01,P<0.05,P<0.01)。结论:高脂膳食诱导IR的小鼠骨骼肌线粒体趋于分裂,呼吸功能和ATP合成能力下降,可能是高脂膳食诱导IR的机制之一。长期有氧运动训练使正常和IR小鼠骨骼肌线粒体融合和分裂均增强,促进线粒体呼吸功能和ATP合成能力,有利于预防和改善IR。     

有氧运动对高脂膳食诱导的胰岛素抵抗小鼠骨骼肌细胞胰岛素受体底物1及其丝氨酸磷酸化活性的影响

目的:探讨有氧运动对高脂膳食诱导胰岛素抵抗(insulin resistance,IR)小鼠骨骼肌细胞胰岛素受体底物1(insulin receptor substrates-1,IRS1)及其丝氨酸磷酸化活性的影响,以及结节性硬化复合物蛋白2(tuberous sclerosis complex-2,TSC2)在此过...     

蛋白组学技术研究有氧运动影响C57BL/6小鼠骨骼肌代谢系列报道之四——有氧运动对胰岛素抵抗小鼠骨骼肌蛋白折叠/降解通路相关蛋白的影响

目的:运用蛋白组学技术研究有氧运动对胰岛素抵抗(Insulin Resistance,IR)小鼠骨骼肌蛋白表达的影响,初步探究骨骼肌蛋白质折叠/降解通路相关蛋白在有氧运动改善IR过程中的作用机制。方法:选取80只4周龄C57BL/6雄性小鼠,随机分为正常饮食组(NC,n=20)和IR模型组(n=60)并分别饲以基础和高脂饲料10周。10周后通过检测空腹血清胰岛素水平(Fasting Insulin,FIN)及口服葡萄糖耐量试验(Oral Glucose Tolerance Test,OGTT)鉴定IR模型是否成功。选取40只成模小鼠,再次随机分为高脂饮食运动组(HE)和高脂饮食安静组(HC)。HE组小鼠采用6周75%VO2 max有氧跑台运动训练。运动结束后处死动物、提取各组小鼠股四头肌总蛋白,经Bradford法检测蛋白浓度后进行蛋白质双向电泳(2-DE),采用ImageMaster 2D Platinum V5.0软件分析2-DE电泳图谱,并对所选取的差异蛋白点用基质辅助激光解吸附离子化飞行时间质谱(Matrix-assisted Laser Desorption/Ionization Time-of-Flight MassSpectrometry,MALDI-TOF-MS)和高效液相色谱-串联谱法(Liquid-Chromatography–tandemMass Spectrometry,LC-MS/MS)进行分析,经Mascot检索软件结合NCBI nr数据库鉴定差异蛋白后使用相关软件对所得数据进行统计分析。结果:10周高脂饮食后,IR模型组小鼠FIN水平比NC组增加50%,OGTT曲线峰值时间点显著后移并出现平台期,提示10周高脂饮食可诱导小鼠产生IR。6周有氧跑台运动后,HE组小鼠FIN水平较HC组下降17.2%,OGTT曲线峰值下降且时间点前移,平台期消失,表明6周有氧运动可显著改善IR小鼠症状。经双向电泳显影,设定1.5倍为筛选差异表达蛋白的标准,比较HC组与HE组蛋白,共发现差异表达蛋白22个,其中运动后表达下调蛋白14个,表达上调蛋白8个。差异表达蛋白中有5个蛋白与细胞蛋白折叠/降解通路密切相关。其变化倍数分别为:纤维蛋白原β链前体(Fibrinogen Beta Chain Precursor)运动后下降38%,β型蛋白酶体7前体(Proteasome Subunit Beta Type-7 Precursor)运动后增加3.27倍,α型蛋白酶体1(Proteasome Subunit Alpha Type-1)运动后增加1.67倍,伴侣素β亚基(Chaperonin ContainingTcp-1 Beta Subunit,CCTβ)、Ester Hydrolase C11Orf54 Homolog为运动后新增蛋白。结论:6周有氧运动可通过调节IR小鼠骨骼肌蛋白折叠/降解通路相关蛋白的表达,改善高脂饮食诱导的IR。     

Effects of dietary fat on muscle substrates,metabolism, and performance in athletes

INTRODUCTION: The present investigation aimed at identifying differences in muscle structural composition, substrate selection, and performance capacity in highly trained endurance athletes as a consequence of consuming a high-fat or a low-fat diet. METHODS: Eleven duathletes ingested high-fat (53% fat; HF) or high-carbohydrate diets (17% fat; LF) for 5 wk in a randomized crossover design. RESULTS: In m. vastus lateralis, oxidative capacity estimated as volume of mitochondria per volume of muscle fiber (HF: 9.86 +/- 0.36 vs LF: 9.79 +/- 0.52%, mean +/- SE) was not different after the two diet periods. Intramyocellular lipid (IMCL) was significantly increased after HF compared with LF (1.54 +/- 0.27% vs 0.69 +/- 0.09%, P = 0.0076). Glycogen content was lower after HF than after LF, but this difference was not statistically significant (487.8 +/- 38.2 vs 534.4 +/- 32.6 mmol x kg-1 dry weight, P = 0.2454). Maximal power and [OV0312]O(2max) (63.6 +/- 0.9 vs 63.9 +/- 1.2 mL O(2) x min-1 x kg-1 on HF and LF) during an incremental exercise test to exhaustion were not different between the two diet periods. Total work output during a 20-min all-out time trial (298 +/- 6 vs 297 +/- 7 W) on a bicycle ergometer as well as half-marathon running time (80 min 12 s +/- 86 s vs 80 min 24 s +/- 82 s) were not different between HF and LF. Blood lactate concentrations and respiratory exchange ratios (RER) were significantly lower after HF than after LF at rest and during all submaximal exercise loads. CONCLUSIONS: Muscle glycogen stores were maintained after a 5-wk high-fat diet period whereas IMCL content was more than doubled. Endurance performance capacity was maintained at moderate to high-exercise intensities with a significantly larger contribution of lipids to total energy turnover.     

有氧运动对C57BL/6小鼠骨骼肌PPARα及CPT-1的影响

目的:研究8周有氧运动对高脂饮食小鼠血脂及骨骼肌中脂质代谢相关因子的影响,探讨过氧化物酶体增殖物激活受体α(PPARα)与运动改善脂质代谢的关系。方法:雄性C57BL/6小鼠60只,随机分为正常饮食安静(NC)及运动组(NE)、高脂饮食安静(HC)及运动组(HE)。其中,HC与HE组均喂以高脂饲料;NE和HE组进行为期8周的无负重游泳训练。实验结束后,采用酶法和比色法分别检测血脂和游离脂肪酸(FFA)水平,并采用NorthernBlot、WesternBlot检测各组小鼠骨骼肌中PPARα、肉毒碱棕榈酰转移酶1(CPT-1)基因及蛋白表达。结果:高脂饮食条件下,运动组血清TG、TC、LDL及FFA比安静组显著降低,HDL显著升高;并且运动组骨骼肌PPARα及CPT-1的mRNA和蛋白表达均较安静组有所提高,尤其HE组表达量较HC组显著提高。结论:运动可有效促进脂肪酸的利用而改善血清脂质水平,并且可使骨骼肌PPARα、CPT-1表达量在转录和翻译水平上均有所提高,提示PPARα作为一个重要的脂质调节因子,在运动改善血脂中发挥着积极的作用。     

高脂饮食大鼠高住高练模型的建立

目的:建立高脂饮食致肥胖大鼠的高住高练0～4周动物模型,观察高住高练对肥胖大鼠的时序性影响。方法:出生21天离乳SD雄性大鼠280只,体重(42.7±4.7)g,随机选20只普通饲料喂养,其余260只高脂饲料喂养,自由饮食饮水。饲养10周后,随机选取普通饮食大鼠和高脂饮食大鼠各10只,称重、量身长,计算体重指数;取肾周和附睾脂肪垫称重计算脂体比;取血测血脂;从体重、体脂和血脂角度验证肥胖与否。验证肥胖后从高脂饮食组挑选出160只肥胖大鼠,进行适应性训练,确定常氧下训练强度为26 m/min。根据适应训练的情况保留130只大鼠进行正式实验,分成对照组,低住低练1、2、3、4周组,低氧安静1、2、3、4周组,高住高练1、2、3、4周组,保证各组间大鼠体重无显著性差异。用水平动物跑台进行耐力训练,持续运动1 h/d,6 d/w,1～4 w。低氧氧浓度为13.6%(约相当于3500 m高度)。根据血乳酸确定低氧下训练强度。结果:饲养10周后,普通饮食大鼠体重(425.1±54.2g)和身长(24.0±1.3cm)均显著(P<0.05)高于高脂饮食大鼠(362.7±37.9 g;22.3±0.7 cm),两组大鼠肾周脂肪和附睾脂肪重绝对值之间无显著差异,高脂饮食大鼠体重指数(320.39±13.55)和脂体比(0.99±0.15)%均高于普通饮食组(305.48±11.49,0.61%±0.29%),且具有显著性(P<0.05)和高度显著性(P<0.01)差异。高脂饮食大鼠胆固醇(1.91±0.26 mmol/L)、甘油三酯(0.59±0.25mmol/L)水平显著性(P<0.05)和高度显著性(P<0.01)高于普通饮食组(1.58±0.21 mmol/L、0.40±0.14 mmol/L),高脂饮食组大鼠低密度脂蛋白(0.20±0.04 mmol/L)与普通饮食组大鼠(0.15±0.03mmol/L)比较,高度显著性升高(P<0.01)。常氧26 m/min与低氧21 m/min运动后大鼠血乳酸较为接近。结论:(1)高脂饮食大鼠具有体脂比例、大鼠体重指数和血脂代谢紊乱的多重表现,可视为肥胖造模成功。(2)常氧下25～26 m/min的训练强度和13.6%低氧下20～21 m/min的训练强度相对于高脂饮食大鼠的代谢反应来说是相同的。     

Sports correlate with positive living habits. Results from the population survey the Swiss MONICA project

Exercise is associated with positive health habits: Findings from the populations survey of the Swiss MONICA-project. Relatively little is known on population-wide relations of habitual exercise to relevant health factors such as diet, cigarette smoking and overweight. Data from a population-based sample of approximately 800 men and women each, aged 25-64, collected in western Switzerland as a part of an international WHO-project, were used to examine cross-sectionally the interrelationships between different lifestyle factors. Men and women training regularly (i.e. greater than or equal to 2 times/wk) exhibited consistently and highly significantly more favourable health habits, regarding diet (i.e. trimming visible fat, higher intake of fruits, salad and vegetables, yogurt and cottage cheese), nonsmoking, and weight control. Men and women with at least some regular physical activity during leisure-time had in turn more favourable health habits than their sedentary counterparts. In both sexes, educational level was directly related to exercise and a healthy diet, and inversely related to smoking and relative weight. Regularly training men and women also had a significantly improved lipid profile compared to inactive ones. It is concluded from this study that leisure-time physical activity and exercise are related to a positive health behaviour including diet, nonsmoking and efficient weight control. This may suggest that exercise should possibly be integrated into any population-wide attempts and efforts to promote health to enhance primary prevention.     

长期游泳训练和补充大豆多肽对高脂饮食大鼠胰岛素抵抗形成的干预作用

目的:探讨长期游泳训练和补充大豆多肽(SPH)对高脂饮食大鼠胰岛素抵抗(IR)形成的干预作用及其机制。方法:60只雄性SD大鼠随机分成对照组、高脂饮食组、高脂饮食 SPH组、高脂饮食 运动组和高脂饮食 运动 SPH组5组。除对照组外,在给大鼠喂饲高脂饮食的同时,按分组方案分别进行10周60min的游泳训练或/和补充SPH(500mg/kgBW),实验结束时测定空腹血糖(FPG)、空腹胰岛素(FINS)、血清C肽(CP)等指标,并计算胰岛素敏感性指数(ISI)、稳态模型-IR指数(HOMA-IR)。结果:(1)10周高脂饮食后大鼠FPG、FINS、HOMA-IR显著升高,而ISI显著降低,但血清CP含量无显著性变化;(2)在高脂饮食诱导大鼠IR形成的同时,进行游泳锻炼或补充SPH,可以显著降低高脂饮食大鼠FPG、FINS、HOMA-IR,提高ISI,但对血清CP含量无显著影响,运动联合补充SPH可使高脂饮食大鼠FINS、HOMA-IR进一步降低,ISI进一步升高,但无显著性差异,同时使血清CP含量显著升高。结论:(1)10周高脂饮食可以诱导大鼠IR形成,这可能与高脂饮食大鼠胰岛素敏感性(IS)降低有关;(2)运动训练或补充SPH可以通过改善机体IS预防高脂饮食大鼠IR的形成。但运动训练联合补充SPH能否对预防高脂饮食大鼠IR的形成具有协同促进作用还有待于进一步研究。     

有氧运动和饮食干预对胰岛素抵抗小鼠骨骼肌脂联素—腺苷酸活化蛋白激酶信号系统的影响研究

目的:探讨有氧运动和饮食干预对胰岛素抵抗(IR)小鼠骨骼肌球形脂联素(G-Adiponectin)及腺苷酸活化蛋白激酶(AMPK)的影响,为运动和饮食辅助防治IR的研究提供理论依据。方法:选用雄性C57BL/6小鼠30只,随机分为正常饮食和IR模型组,后者喂养8周高脂饲料后建立胰岛素抵抗(IR)模型,再将IR模型组分为高脂饮食安静组(HC)、高脂饮食运动组(HE)、正常饮食安静组(HNC)和正常饮食运动组(HNE)。运动组进行6周跑台训练,高脂饮食组继续6周的高脂饮食。实验8周后,采用ELISA法检测小鼠血清空腹胰岛素水平及以口服糖耐量试验(OGTT)检测葡萄糖耐量。14周后,采用NorthernBlot检测腓肠肌AMPKmRNA表达,WesternBlot和免疫荧光染色检测腓肠肌G-Adiponectin、AMPK和pAMPK-Thr172蛋白表达。采用酶法测定小鼠血清甘油三酯(TG)和胆固醇(TC)含量。结果:HE和HNE组骨骼肌细胞AMPKmRNA和蛋白以及pAMPK-Thr172蛋白分别较HC及HNC组表达显著增高;HNE组G-Adiponectin显著高于HNC组;HNC组AMPK蛋白和mRNA表达均显著高于HC组;各组免疫荧光检测结果与WesternBlot结果一致。结论:有氧运动和饮食干预均能有效增强Adiponectin-AMPK信号通路,改善机体的脂质代谢紊乱,从而产生防治IR的效果。     

Effects of short-term fat adaptation on metabolism and performance of prolonged exercise

The concept of manipulating an individuals habitual diet before an exercise bout in an attempt to modify patterns of fuel substrate utilization and enhance subsequent exercise capacity is not new. Modern studies have focused on nutritional and training strategies aimed to optimize endogenous carbohydrate (CHO) stores while simultaneously maximizing the capacity for fat oxidation during continuous, submaximal (60-70% of maximal O(2) uptake [(.)VO(2max)] exercise. Such "nutritional periodization" typically encompasses 5-6 d of a high-fat diet (60-70% E) followed by 1-2 d of high-CHO intake (70-80% E; CHO restoration). Despite the brevity of the adaptation period, ingestion of a high-fat diet by endurance-trained athletes results in substantially higher rates of fat oxidation and concomitant muscle glycogen sparing during submaximal exercise compared with an isoenergetic high-CHO diet. Higher rates of fat oxidation during exercise persist even under conditions in which CHO availability is increased, either by having athletes consume a high-CHO meal before exercise and/or ingest glucose solutions during exercise. Yet, despite marked changes in the patterns of fuel utilization that favor fat oxidation, fat-adaptation/CHO restoration strategies do not provide clear benefits to the performance of prolonged endurance exercise.     

Exercise alone is an effective strategy for reducing obesity and related comorbidities

The commonly held view that exercise alone is not a useful strategy for obesity reduction is drawn from studies with limitations that confound interpretation. Recent evidence counters the dogma that daily exercise produces only modest weight loss and suggests that exercise without diet restriction is an effective strategy for reducing obesity and related co-morbidities.