Intensity of Treadmill Training and its Effect on Body Composition in Rats

Abstract

The purpose of this study was to determine which of three intensities of treadmill training produced changes in body composition in rats as evidenced by body weight, percentage of fat and specific gravity. Subjects were 60 male Wistar rats 25 to 30 days old when obtained. They were randomly assigned to one of five groups: sedentary controls, spontaneously active controls, and three groups of rats forced to exercise on a treadmill at intensities of 75, 125 and 175 fpm. Forced exercise was applied three times a week for 8 weeks, after which measures of body weight, specific gravity, and percentage of body fat were obtained. Results indicated that the sedentary controls had significantly higher mean body weights than did those which exercised. Rats forced to exercise at 75 fpm had significantly lower specific gravity measures than rats trained at 125 fpm. Sedentary controls had lower specific gravity values than did all rats allowed to exercise. Intensity of treadmill training had no effect on percentage of body fat as determined chemically. However, exercise was effective in reduction of body fat.     

Effects of Differing Prepuberty Exercise Programs on the Emotionality of Male Albino Rats

Abstract

The problem under investigation in this study was to determine if differing programs of prepuberty exercise had any effect upon the emotionality of male albino rats at puberty. The subjects were 48 male albino rats of the Sprague-Dawley strain who were subjected to a 35-day training program under conditions of sedentary existence, voluntary exercise, or forced exercise. At the end of the experimental period the animals were tested in an open field marked into 49 consecutively numbered 7 1/2-in. squares.

Emotionality in the open field was determined by two methods: (a) the total number of squares traversed by an animal in 5 min., and (b) the total number of squares traversed by an animal toward the center of the field. The relationship between exploratory behavior and emotionality is considered to be an inverse one, that is, the more exploratory the behavior, the less emotionality the animal exhibits.

The results indicated that the animals which had been subjected to the forced exercise regimen traversed significantly more squares under both testing conditions and therefore evidenced more exploratory behavior and therefore less emotionality than the animals in the voluntary exercise and sedentary groups. There were no significant differences on either measure of exploratory behavior between the voluntary exercise and sedentary groups.     

Effects of interval aerobic training combined with strength exercise on body composition,glycaemic and lipid profile and aerobic capacity of obese rats

The purpose of this study was to investigate the effects of interval aerobic training combined with strength exercise in the same training session on body composition, and glycaemic and lipid profile in obese rats. Sixteen lean Zucker rats and sixteen obese Zucker rats were randomly divided into exercise and sedentary subgroups (4 groups, n = 8). Exercise consisted of interval aerobic training combined with strength exercise in the same training session. The animals trained 60 min/day, 5 days/week for 8 weeks. Body composition, lipid and glycaemic profiles and inflammatory markers were assessed.

Results showed that fat mass was reduced in both lean and obese rats following the exercise training (effect size (95% confidence interval (CI)) = 1.8 (0.5–3.0)). Plasma low-density lipoprotein–cholesterol and fasting glucose were lower in the exercise compared to the sedentary groups (d = 2.0 (0.7–3.2) and 1.8 (0.5–3.0), respectively). Plasma insulin was reduced in exercise compared to sedentary groups (d = 2.1 (0.8–3.4)). Some exercise × phenotype interactions showed that the highest decreases in insulin, homeostatic model assessment-insulin resistance, fasting and postprandial glucose were observed in the obese + exercise group (all, P < 0.01). The findings of this study suggest that interval aerobic training combined with strength exercise would improve body composition, and lipid and glycaemic profiles, especially in obese rats.     

Effects of Exercise and Milk Consumption on Blood Serum Cholesterol in Rats

Abstract

This study investigated the effects of exercise on blood cholesterol and correlated those effects with estimates of body fat through experiments with 45 albino weanling rats (15 litter mate trios). The rats were confined to individual cages in a temperature-controlled room and fed a stock diet until they were 11 weeks old. At this time the trios were divided. Group A was continued on a stock diet and exercised for an hour in the morning and an hour in the afternoon by forced swimming. Group B was subjected to the same exercise but a portion of the stock diet was replaced with powdered whole milk, so that 30 percent of the caloric intake was derived from the whole milk supplement. Group C was fed the stock diet but activity was restricted. After 15 weeks blood samples were taken, the animals sacrificed, and the heart and adrenals weighed. The specific gravity of the carcass was also determined. Exercise resulted in a statistically significant decrease in total and free blood serum cholesterol concentration. These animals were also leaner and had larger hearts and adrenal glands. Serum cholesterol was negatively related to carcass specific gravity. The milk supplement had no significant effect on any of these measures. Several possible explanations for the effects of exercise on blood cholesterol are discussed.     

Melatonin administration does not alter muscle glycogen concentration during recovery from exhaustive exercise in rats

Abstract

The purpose of this study was to investigate the effect of melatonin administration on muscle glycogen concentration during recovery after exhaustive swimming exercise in sedentary and trained rats. Male Wistar rats were assigned to one of four groups: sedentary control (C), sedentary melatonin-injected (M), exercise-trained (T), and trained and melatonin-injected (MT) groups. Exercise-trained groups were subjected to six weeks of swimming exercise. All rats completed an exhaustive swimming exercise. Two daily subcutaneous injections of melatonin at a dose of 3 mg·kg^?1 were given to the rats in the M and MT groups immediately after the exhaustive exercise. Plasma melatonin, glucose and lactate concentrations, and glycogen concentrations of the soleus and epitrochlearis muscle tissues were measured after exhaustive exercise. Plasma lactate concentration was significantly lower in the T and MT groups than in the C group. Plasma melatonin concentration was higher in the supplemented groups than in the C group. Plasma glucose concentration was significantly higher in the T and MT groups than in the C group. Both epitrochlearis and soleus muscle glycogen concentrations were higher in the trained groups than in the C group. In conclusion, although exercise training results in improvement in muscle glycogen, exogenous melatonin administration after exhaustive exercise did not restore the glycogen concentrations in fast- or slow-twitch muscle tissues.     

Effects of training on spleen and peritoneal exudate reactive oxygen species and lymphocyte proliferation by splenocytes at rest and after an acute bout of exercise

Abstract

The purpose of this study was to analyse the effect of regular exercise on spleen and peritoneal exudate reactive oxygen species (ROS) and lymphocyte proliferation by splenocytes. Twenty-four female BALB/c mice were randomly divided into trained (n = 12) and untrained (n = 12) groups. These two groups were further divided into mice that were studied at rest (trained/rest, n = 5; untrained/rest, n = 6) and immediately after a 2 h acute bout of exercise (trained/exercise, n = 6; untrained/exercise, n = 6). The animals were bred in the animal facility of the Yonsei University College of Medicine, where they were housed in a temperature- (22 – 24°C) and humidity- (50 – 60%) controlled environment, with a 12 h photoperiod, and provided with food and water ad libitum. The trained mice underwent 10 weeks of endurance swimming training (5 days per week) in water at 26 – 29°C for 60 min. Changes in body mass, proliferative activity and the production of reactive oxygen species from spleen lymphocytes and peritoneal exudate cells were determined. The splenic lymphocytes of the trained mice had much greater proliferative activity than those of the untrained mice (P < 0.05). Trained mice had lower ROS production in splenic lymphocytes and peritoneal exudate cells than untrained mice. In both groups, there was substantial inhibition of proliferative activity stimulated with medium, concanavalin A and lipopolysaccharide following the acute bout of exercise. This may have been caused by excessive ROS production following the acute exercise session.     

Delayed preconditioning-mimetic actions of exercise or nitroglycerin do not affect haemodynamics and exercise performance in trained or sedentary individuals

Abstract

Nitroglycerin induces the so-called second window of protection (SWOP), which alleviates myocardial damage and stunning after ischaemia/reperfusion. To determine whether myocardial performance during exercise is improved in the second window of protection, we studied the haemodynamic responses of 12 trained and 11 sedentary individuals during a sequence of maximal tests on a cycle ergometer. A baseline test (basal test) was followed by a second effort performed during the second window of protection (exercise-SWOP test). Haemodynamics was also evaluated after pharmacologically induced SWOP 48 h after transdermal administration of 10 mg of nitroglycerin (pharmacologically induced SWOP test). The exercise-SWOP and pharmacologically induced SWOP tests were separated by a 1-week washout period. Endothelial-dependent vasodilatation after nitroglycerin pre-treatment was also assessed in five sedentary individuals to determine whether nitrate donors could affect vascular function. We found that nitroglycerin pre-treatment did not induce any improvement in haemodynamics in either trained or sedentary individuals, since maximum values of workload, heart rate, stroke volume, cardiac output, myocardial contractility, and double product were similar between the exercise-SWOP and pharmacologically induced SWOP tests in both groups. Furthermore, nitroglycerin pre-treatment did not alter flow-mediated dilation during pharmacologically induced SWOP. Although nitroglycerin pre-treatment alleviates post-ischaemic myocardial stunning, our results suggest that it does not affect the myocardial performance of healthy individuals during exercise performed in the second window of protection, independently of the training status of the individuals. Moreover, nitroglycerin pre-treatment does not ameliorate endothelial function.     

有氧运动对大鼠血清瘦素水平(Leptin)的影响

为探讨有氧运动对大鼠血清中瘦素(leptin)含量的影响及变化的时相性,把SD(Spragne-Dawley)大鼠分为安静对照组(C)和有氧运动后即刻组(T0)、24h 组(T1)、48 h组(T2)、72h 组(T3)进行比较性研究.结果发现:与安静对照组相比,6周有氧跑台运动后,T0、T1、T2、T3组体重、体重增加量均显著低于对照组(前者P<0.01,后者P<0.05),双侧附睾脂肪垫重量显著低于对照组(P<0.05);血清瘦素含量,T1、T2、T3 组显著下降(P<0.01),T0组有下降趋势,但不具有显著性差异(P>0.05).各组下降的幅度分别为4%、20%、42%、15%,其中,T2组下降最明显.有氧运动各组相比,T2与 T0组相比显著下降(P<0.01),T2与T1组相比显著下降(P<0.05),T3与T2组相比显著升高(P<0.01).结论:有氧运动能够减少大鼠体重、体重增加量和腹部脂肪积累,调节脂代谢,防止肥胖和高脂血症的作用;降低血清 Leptin 水平,而且 Leptin 水平的下降具有时相性,可能是由于最后一次运动所产生的延迟作用造成的;体内 Leptin 含量下降与体脂减少密切相关,正常生理状态下运动降低血清瘦素水平是机体为维持自身体重稳定和能量平衡的一种适应性反应.     

大强度运动对去卵巢大鼠骨量的影响

成年ＳＤ大鼠去卵巢建立骨质疏松模型,用骨形态计量学方法,研究８周的跑台运动对大鼠胫骨近心干骺端松质骨骨量减少的影响。结果：去卵巢安静组大鼠骨量减少,骨形成增加,骨吸收增加,为高转换型的骨代谢。去卵巢后大强度运动与去卵巢安静组大鼠各项指标相比无显性差异。     

Effects of Forced Exercise on Spontaneous Activity and Body Weight of Adult Rats

Abstract

Adult male Wistar rats (N = 47) were divided at random into four groups for a 9-week experimental period. The 11 animals in Group I were permitted spontaneous activity in addition to swimming 15 minutes per day, 5 days per week. The 10 animals in Group II ran on a treadmill for 15 minutes per day, 5 days per week in addition to spontaneous activity. The 12 animals in Group III were permitted spontaneous activity but engaged in no forced exercise, and the 14 animals in Group IV were restricted to their cages during the entire experimental period. Results indicated that Group I engaged in more spontaneous activity than did Groups II and III, and Group II was more active than Group III. Group IV was significantly heavier than Groups I, II, and III, but the latter groups did not differ in body weight.     

Relationship of Organ Weight and Swimming Performance in the Albino Rat

Abstract

The relationship between organ weight and swimming capacity was determined in 42 male albino rats. Upon completion of a 4-week training program, the animals were forced to swim to exhaustion with 2 percent of the body weight attached. They were sacrificed and specific gravity and organ weights determined. The results warrant the following conclusions: A significant (p < .05) but low correlation exists between the relative weight of the spleen and lungs with swimming performance. The correlation of relative heart weight and swimming performance approached statistical significance (p < .06). Attaching a weight proportional to the body weight to increase the energy cost of swimming penalizes the heavier animals. Correcting for the inverse relationship between body weight and swim time does not alter appreciably the relationships between organ weights and swim time.     

高强度运动训练对肿瘤接种大鼠抗肿瘤作用的实验研究

目的:探讨高强度运动训练对Walker 256接种大鼠抗肿瘤的作用。方法:80只大鼠随机分为2组(n=40):运动训练组和非运动训练组。高强度运动训练8周后,运动训练组大鼠又分为两组(n=20):运动对照组和肿瘤种植运动组。非运动训练组大鼠又分为两组(n=20):静坐对照组和肿瘤种植静坐对照组。高强度平台运动训练课程持续10周,5d/W,30min/d,85%VO2max。观测血浆中多种酶、激素和细胞因子水平及淋巴细胞和巨噬细胞和Walk-er 256肿瘤细胞的葡萄糖和谷氨酰胺代谢酶、H2O2生成量、吞噬率和淋巴细胞增殖指数等指标。结果:高强度运动训练能够延长肿瘤接种大鼠的生存时间,降低肿瘤重量,阻止恶病质的发生;高强度运动能够抑制Walker 256肿瘤细胞接种大鼠淋巴细胞和巨噬细胞的葡萄糖和谷氨酰胺代谢酶的活性。结论:高强度运动训练可能是一种有效的潜在的抗肿瘤策略。     

有氧运动对高脂膳食大鼠脂肪组织COX2的影响

目的:旨在观察有氧运动对高脂膳食大鼠白色脂肪组织(WAT)和棕色脂肪组织(BAT)中环氧合酶2(COX2)及其相关基因的影响,以探讨有氧运动促进WAT棕色化及BAT活化以抵抗高脂膳食对机体血脂和体重不利影响的可能机制。方法:雄性SD大鼠随机分为普通对照组(C组)、普通运动组(E组)、高脂对照组(HC组)和高脂运动组(HE组),每组7只。E组和HE组进行中等强度跑台训练。8周干预结束后,计算各组大鼠Lee’s指数,测量体成分,称量WAT(肾周和附睾处)和BAT(肩胛处)湿重;测试血清甘油三酯(TG)和总胆固醇(CHO)含量;RT-qPCR检测BAT中COX2 mRNA的相对表达量;Western blot法检测脂肪组织中肾上腺素能受体β3(Adrβ3)、COX2和解偶联蛋白(UCP1)蛋白含量。结果:1)饲喂第2周起高脂膳食大鼠体重较普通膳食大鼠显著升高,运动第3周起,HE组体重较HC组均显著降低;运动后E组和HE组大鼠的Lee’s指数分别较C组和HC组显著性下降;2)高脂膳食大鼠脂肪含量显著增加,运动后出现显著性下降;与C组相比,HC组WAT湿重显著增加,运动组WAT湿重显著降低,E组BAT%较C组显著升高;3)有氧运动降低高脂膳食大鼠血清CHO和TG水平;4)运动组BAT中COX2 mRNA表达显著高于对照组;5)E组BAT中UCP1、COX2和Adrβ3蛋白表达显著高于C组,HE组WAT中COX2蛋白表达显著高于HC组。结论:有氧运动可降低高脂膳食机体的血脂水平,改善体脂含量和体重,该过程可能与运动激活WAT和BAT中Adrβ3以促进COX2的表达,增加WAT和BAT中UCP1的表达,以促进BAT的活化和WAT的棕色化有关。     

Sedentary behaviour and adiposity in elite athletes

Abstract

Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a health risk. Even in athletes an increased adiposity affects health and performance. Sedentary behaviour has been associated with higher levels of adiposity, independent of moderate-to-vigorous physical activity. However, it is unclear whether this independent relationship still exists in highly trained athletes. The aim of this study was to examine the association of sedentary behaviour with body fatness in elite athletes. Cross-sectional data from 82 male athletes (mean age 22 years) were used. Total and regional body composition was measured by dual energy X-ray absorptiometry. Self-reported time spent in sedentary behaviour and weekly training time was assessed in all participants at one time point and multiple regression analyses were used. Sedentary behaviour predicted total fat mass (β = 0.77; 95% CI: 0.36–1.19, P < 0.001) and trunk fat mass (β = 0.25; 95% CI: 0.07–0.43, P = 0.007), independent of age, weekly training time, and residual mass (calculated as weight-dependent variable) but not abdominal fat. Also, no associations of sedentary behaviour with fat-free mass, appendicular lean soft tissue, and body mass index were found. These findings indicate that athletes with higher amounts of sedentary behaviour presented higher levels of total and trunk fatness, regardless of age, weekly training time, and residual mass. Therefore, even high moderate-to-vigorous physical activity levels do not mitigate the associations between sedentary behaviour and body fatness in highly trained athletes.     

运动频率和递增强度运动对大鼠海马神经发生的影响

目的:探讨运动频次和隔周递增强度运动对大鼠海马神经发生的影响.方法:将60只雄性5周龄SD大鼠随机分为安静对照(C)组、每天运动(E0)组、隔1日运动(E1)组、隔3日运动(E3)组、隔周运动(E7)组和隔周递增强度运动(E7I)组.运动方式为跑台运动.腹腔注射BrdU于各组大鼠,持续注射6天.采用免疫组织荧光染色技术,检测各组大鼠海马齿状回内新生细胞和新生神经元数量.结果:各组动物海马齿状回内BrdU免疫阳性(Br-dU+)细胞数目为:C组37.62±9.02,E0组46.01±10.82,E1组49. 06±12. 07,E3组41. 20±11. 02,E7组37.23±16. 45,E71组53. 97±10. 67.各组大鼠海马齿状回内BrdU和NeuN免疫双阳性(BrdU++NeuN+)细胞微分别为:C组15.26±4.42;E0组17. 61±3. 86,E1组21. 93±5.60,E3组16. 28±5.37,E7组15. 80±7.50,E7I组24. 9±土5.44.结论:在间隔不同时问的小强度运动中,隔日小强度运动最有利于大鼠海马齿状回神经发生;隔周递增运动强度也有利于大鼠海马齿状回神经发生,     

Whole body vibration: unsupervised training or combined with a supervised multi-purpose exercise for fitness?

Abstract

The aim of the study was to compare the effect of an unsupervised whole body vibration (WBV) training and two different supervised multi-purpose exercise programmes, with and without WBV, on body composition, functional fitness and self-reported well-being in middle-aged adults. Fifty-four healthy participants (age 48.6 ± 6.7 years) were randomly assigned to a vibration group (VG), a multi-purpose exercise group (MG) and a multi-purpose exercise with vibration group (VMG) and trained 3 days a week for 4 months. VG performed a standardised unsupervised WBV protocol, MG a supervised multi-purpose exercise and VMG a multi-purpose exercise including vibration. After training, drop out was significantly higher in VG group (P = 0.016) when compared to VMG group. In both MG and VMG, body composition, sit-up, push-up, sit and reach, agility test, hopping test and self-reported general health significantly improved (P < 0.05). No additive effects were generated by the vibration stimulus. Percentage of body fat and agility test in VG had a significant opposite trend compared to VMG group (P < 0.05). In summary, an unsupervised WBV training should not be chosen for training protocol. However, positive effects on physical fitness and the best results in adherence could be achieved integrating WBV practice into a multi-purpose exercise training.     

Effects of aerobic training on serum omentin-1 and cardiometabolic risk factors in overweight and obese men

Abstract

Omentin-1 is a newly discovered protein expressed and secreted from visceral adipose tissue that increases insulin sensitivity. We examined the effects of 12 weeks of aerobic training on serum omentin-1 concentrations together with cardiovascular risk factors in overweight and obese men. Eighteen overweight and obese participants (age 43.1 ± 4.7 years, BMI ≥25 kg · m^?2) were assigned to exercise training (n = 9) and control (n = 9) groups. A matched control group of normal weight participants (n = 8; age 42.2 ± 3.8 years, BMI <25 kg · m^?2) were also recruited for baseline comparison. The obese exercise group participated in 12 weeks of progressive aerobic training 5 days a week. Measures of serum omentin-1, insulin resistance, lipid profiles, blood pressure, and body composition were obtained before and after the 12 weeks. At baseline, normal weight participants had significantly higher serum omentin-1 concentrations than overweight and obese participants, and there were inverse correlations between omentin-1 and each of waist circumference, fasting glucose, insulin resistance, total cholesterol, triglyceride, and systolic blood pressure (P < 0.05). After the aerobic training, waist circumference, percent body fat, fasting glucose, insulin resistance, triglyceride, total cholesterol, low-density lipoprotein cholesterol, and systolic blood pressure were all significantly decreased (P < 0.05). In contrast, serum omentin-1 concentration was significantly increased after the aerobic programme (P < 0.05), and correlated with changes in insulin resistance (r = ?0.67, P = 0.04), glucose (r = ?0.65, P = 0.05), waist circumference (r = ?0.70, P = 0.03), and aerobic fitness r = ?0.68, P = 0.04). Aerobic training resulted in an improvement in cardiometabolic risk factors in obese participants, and this improvement was accompanied by increased omentin-1 concentrations.     

有氧运动对肺动脉高压大鼠肺动脉舒张功能的影响

目的:了解有氧运动对肺动脉高压大鼠肺动脉血管舒张反应的影响。方法:8周大的雄性SD大鼠,随机分为4组,分别是常氧不运动组(N)、常氧运动组(EX)、肺动脉高压不运动组(H)、肺动脉高压运动组(HE)。将大鼠每天暴露在氧浓度为15.6%～16.1%的环境中8小时,每周7次,制作肺动脉高压模型。运动组分别进行8周每天1小时5天/周游泳训练,第9周分离出大鼠肺动脉,检测4组动脉环乙酰胆碱(Ach)诱导的内皮依赖性和硝普钠(SNP)诱导的非内皮依赖性舒张反应。结果:肺动脉高压组大鼠的肺动脉环的内皮依赖性血管舒张功能明显下降,动脉环经NO途径的最大舒张反应明显降低,有氧运动对肺动脉高压大鼠肺动脉的舒张功能有一定的改善作用,与肺动脉高压对照组及常氧运动组比较差异有统计学意义。结论:实验结果证实有氧运动对NO介导的血管舒张功能的有益调节作用,部分被低氧效应所抵消。长期低氧效应超过有氧运动对肺动脉血管的作用这个现象,很可能与NO途径受损有关。     

血清肌酸激酶与骨骼肌损伤关系的探讨

研究目的在于对血清肌酸激酶与骨骼肌损伤之间的关系进行探讨。采用跑台一次性离心运动至力竭的动物模型,48只7周龄雌性大鼠随机分为安静对照组和运动后即刻、1、2、4和7天组,测定血清肌酸激酶活性,同时通过HE染色分析骨骼肌形态学损伤变化。结果显示血清肌酸激酶活性峰值出现在运动后即刻,运动后1天迅速下降。HE染色结果则表明离心运动后骨骼肌损伤呈现延迟性时相特点,在运动后第2天骨骼肌损伤范围达到最大。本实验表明血清肌酸激酶与骨骼肌损伤的变化趋势并不一致,血清肌酸激酶水平不能反映骨骼肌损伤。     

Effects of Exercise on the Basal Concentration of ATP in Muscle Tissue

Abstract

The problem involved the determination of the base concentration of ATP in muscle tissue of white rats. These animals had been forced to exercise (train) by swimming.

The method used to analyze for ATP involved bioluminescene and spectrophotometry. The luciferin-luciferase system served as the bioluminescence source. The Fisher's t test for significance was computed from the data collected. The peak height, obtained from the reaction of ATP and the luciferase system which was recorded, indicated the amount of ATP present.

The results obtained were not significant at the .05 level. Based on the findings of this study it was concluded that there was not a significant change in the base concentration of ATP in the experimental rats as compared to the control rats, and that there was a definite trend of an increased basal concentration of ATP in the exercised animals.