Effects Of Chronic Physical Exercise Research Articles

Exercise-mediated increase in PGC1α and MEF2 expression in type 2 diabetes mellitus

Sedentarism accounts for exacerbated fat storage in skeletal muscle that can impair mitochondrial biogenesis and progress to Type 2 Diabetes (T2D). A signaling pathway coordinated by coactivators and transcription factors such as myocyte stimulating factor 2 (MEF2), peroxisome proliferator-activated receptor 1-alpha (PGC1α), and mitochondrial transcription factor (TFAM) is essential to preserve mitochondrial function. So, we tested the effect of chronic physical exercise on the expression of MEF2, PGC1α, and TFAM, in gastrocnemius. Were analyzed lipidic profile, fasting glucose, and gene expressions (PGC1 α, TFAM, MEF2) in muscle obtained from Wistar rats divided into four groups: Control (fed with balanced chow and sedentary), Exercised (fed with balanced chow and exercised), T2D (fed with high-fat chow + a low dose of streptozotocin and sedentary) and T2D-exercised (fed with high-fat diet + a low dose of streptozotocin and exercised). Exercised group exhibited increased expression of PGC1α and MEF2 compared to the Control and T2D groups (sedentary or exercised). PGC1α was higher in Exercised by 143 % compared to Control, and by 220 % compared to T2D groups. MEF2 was 39 % higher in Exercised group when compared to the T2D group and 300 % higher than the exercised T2D group. High-Density Lipoprotein was positively associated with PGC1α expression, probably associated with the improvement in mitochondrial function in exercised animals, and fasting glucose was negatively associated with MEF2, probably related to impaired mitochondrial functioning in animals with T2D. We conclude that physical could improve some T2D harming effects by enhancing mitochondrial biogenesis and homeostasis.

Acute and chronic effects of physical exercise on IgA and IgG levels and susceptibility to upper respiratory tract infections: a systematic review and meta-analysis.

This systematic review and meta-analysis aimed at evaluating acute and chronic effects of physical exercise on IgA and IgG levels, as well as its relationship with the susceptibility to develop upper respiratory tract infections (URTI). This systematic review and meta-analysis was conducted and reported in accordance with PRISMA statement. A systematic search of PubMed, Web of Science, and EMBASE was performed in July 2020. This systematic review and meta-analysis included studies in which participants performed acute exercise or chronic physical training and were subjected to analyses of URTI incidence and concentrations of IgA and IgG. The selected studies for systematic review were divided into the following three groups: (I) trials that evaluated the effects of acute exercise in sedentary subjects, (II) trials that evaluated the effects of acute exercise in athletes/trained individuals, and (III) trials that evaluated the effects of chronic physical training on the incidence of URTI, as well as on the levels of IgA and IgG. Acute exercise increases the IgA levels in trained subjects but does not affect its levels in untrained subjects. Such increase in IgA levels induced by acute exercise is greater in trained individual that performed ultramarathon. On the other hand, chronic physical training reduces IgA levels in both trained and untrained subjects, does not change IgA levels in non-military subjects, besides from not affecting IgG levels. The present systematic review and meta-analysis indicates that acute exercise positively influences IgA levels in trained individuals, being this effect pronounced when a strenuous exercise such as ultramarathon is executed. Chronic physical training, in turn, does not affect IgG levels.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00424-022-02760-1.

The growing field of immunometabolism and exercise: Key findings in the last 5 years.

This perspective review highlights the impact of physical exercise on immunometabolic responses in the past 5 years. Understanding immunometabolism as a part of immunological research is essential. Furthermore, the roles of both acute and chronic effects of physical exercise on health, aging, and chronic diseases in immunometabolic changes should be elaborated. In immune cells, β2 adrenergic signaling stimulates the preferential mobilization of inflammatory phenotypes, such as CD16+ monocytes and CD8+ T cells, into the bloodstream after a physical exercise session. The mobilization of immune cells is closely related to the availability of energetic substrates for the cell and mechanisms associated with the uptake and oxidation of fatty acids and glucose. These cells, especially senescent T cells, are mobilized to the peripheral tissues and undergo apoptotic signaling, stimulating the creation of a "vacant space" where new cells will be matured and replaced in the circulation. This results in the upregulation of the expression and secretion of anti-inflammatory cytokines (IL-10 and IL-1ra), leading to increased regulatory immune cells that provide immunoregulatory properties. Thus, we suggest that a significant nutrient available to the cell will favor oxidative metabolism, augment ATP production, and consequently maintain the immune cells in their quiescent state, as well as promote rapid activation function. Therefore, based on the studies discussed in this perspective review, we highlight the importance of performing moderate-intensity continuous and high-intensity intermittent aerobic exercises, due to a higher magnitude of energetic demand and release of anti-inflammatory cytokines (IL-6 and IL-10).

Exercise Improves Redox Homeostasis and Mitochondrial Function in White Adipose Tissue.

Exercise has beneficial effects on energy balance and also improves metabolic health independently of weight loss. Adipose tissue function is a critical denominator of a healthy metabolism but the adaptation of adipocytes in response to exercise is insufficiently well understood. We have previously shown that one aerobic exercise session was associated with increased expression of antioxidant and cytoprotective genes in white adipose tissue (WAT). In the present study, we evaluate the chronic effects of physical exercise on WAT redox homeostasis and mitochondrial function. Adult male Wistar rats were separated into two groups: a control group that did not exercise and a group that performed running exercise sessions on a treadmill for 30 min, 5 days per week for 9 weeks. Reactive oxygen species (ROS) generation, antioxidant enzyme activities, mitochondrial function, markers of oxidative stress and inflammation, and proteins related to DNA damage response were analyzed. In WAT from the exercise group, we found higher mitochondrial respiration in states I, II, and III of Complex I and Complex II, followed by an increase in ATP production, and the ROS/ATP ratio when compared to tissues from control rats. Regarding redox homeostasis, NADPH oxidase activity, protein carbonylation, and lipid peroxidation levels were lower in WAT from the exercise group when compared to control tissues. Moreover, antioxidant enzymatic activity, reduced glutathione/oxidized glutathione ratio, and total nuclear factor erythroid-2, like-2 (NFE2L2/NRF2) protein levels were higher in the exercise group compared to control. Finally, we found that exercise reduced the phosphorylation levels of H2AX histone (γH2AX), a central protein that contributes to genome stability through the signaling of DNA damage. In conclusion, our results show that chronic exercise modulates redox homeostasis in WAT, improving antioxidant capacity, and mitochondrial function. This hormetic remodeling of adipocyte redox balance points to improved adipocyte health and seems to be directly associated with the beneficial effects of exercise.

Effect of Physical Exercise Program Based on Active Breaks on Physical Fitness and Vigilance Performance.

Simple SummaryOur study aimed to analyze the effects of 8 weeks physical training on vigilance performance in high school students. Forty-two healthy students were assigned for convenience and matched into two groups, a Control Group (CG) and an Active-Break Group (ABG). The participants were assessed before the training program using the Alpha-Fitness test battery and Psychomotor Vigilance Task (PVT) to observe their physical fitness and vigilance performance. Compared with the pre-test, significant different were observed in the post-test PVT. Results showed a main effect of ABG responding faster than students in the CG group. This demonstrated that 8 weeks physical training have an effect on vigilance performance and improve the efficiency of vigilance in high school students.The scientific literature has shown the beneficial effects of chronic Physical Exercise (PE) on a wide range of tasks that involve high-order functioning. For this reason, the present study aimed to investigate the effects of active breaks on physical fitness and vigilance performance in high school students through eight weeks of physical training. A total of 42 healthy students (age = 16.50 ± 0.59 years; height = 171.08 ± 8.07 cm; weight = 67.10 ± 13.76 kg) from one Andalusian high school (Spain) were assigned for convenience and matched into two groups, a Control Group (CG) and an Active-Break Group (ABG). The ABG performed two active breaks (based on strength and self-loading exercises) during the school day, first at 10:00 a.m. and second at 12:30 p.m. The participants were assessed before and after the training program using the Alpha-Fitness test battery and the Psychomotor Vigilance Task (PVT). Significant differences were observed in the post-training PVT results, compared with the pretraining PVT, showing ABG responding faster than CG. Thus, the presents study demonstrated that eight weeks of physical training affects vigilance performance (compared to CG) and improves the efficiency of vigilance in high school students, contributing to enhancement of quality of education.

Effects of Physical Exercise on the Expression of MicroRNAs: A Systematic Review.

Silva, FCd, Iop, RdR, Andrade, A, Costa, VP, Gutierres Filho, PJB, and Silva, Rd. Effects of physical exercise on the expression of microRNAs: A systematic review 34(1): 270-280, 2020-Studies have detected changes in the expression of miRNAs after physical exercise, which brings new insight into the molecular control of adaptation to exercise. Therefore, the objective of the current systematic review of experimental and quasiexperimental studies published in the past 10 years was to assess evidence related to acute effects, chronic effects, and both acute and chronic effects of physical exercise on miRNA expression in humans, as well as its functions, evaluated in serum, plasma, whole blood, saliva, or muscle biopsy. For this purpose, the following electronic databases were selected: MEDLINE by Pubmed, SCOPUS, Web of Science, and also a manual search in references of the selected articles to April 2017. Experimental and quasiexperimental studies were included. Results indicate that, of the 345 studies retrieved, 40 studies met the inclusion criteria and two articles were included as a result of the manual search. The 42 studies were analyzed, and it can be observed acute and chronic effects of physical exercises (aerobic and resistance) on the expression of several miRNAs in healthy subjects, athletes, young, elderly and in patients with congestive heart failure, chronic kidney disease, diabetes mellitus type 2 associated with morbid obesity, prediabetic, and patients with intermittent claudication. It is safe to assume that miRNA changes, both in muscle tissues and bodily fluids, are presumably associated with the benefits induced by acute and chronic physical exercise. Thus, a better understanding of changes in miRNAs as a response to physical exercise might contribute to the development of miRNAs as therapeutic targets for the improvement of exercise capacity in individuals with any given disease. However, additional studies are necessary to draw accurate conclusions.

Exercise Increases Adiponectin and Reduces Leptin Levels in Prediabetic and Diabetic Individuals: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

It is speculated that lifestyle interventions known to improve diabetic metabolic state may exert their effects via adipokines. The aim of this systematic review and meta-analysis was to evaluate the chronic effects of physical exercise on adiponectin and leptin levels in adult prediabetic and diabetic individuals. PubMed, Embase, Scopus, The Cochrane Library, clinicaltrials.gov, and WHO Clinical Trials Registry were searched for randomized controlled trials. Pooled effects of interventions were assessed as mean difference (MD) with random effects model. Sensitivity analysis was conducted to test data robustness and subgroup analysis for study heterogeneity. Twenty-two trials with 2996 individuals were included in the meta-analysis. Physical exercise increased levels of adiponectin (MD: 0.42 µg/mL; 95% confidence interval (CI), 0.23, 0.60, p < 0.00001, n = 19 trials) and reduced leptin levels (MD: −1.89 ng/mL; 95% CI, −2.64, −1.14, p < 0.00001, n = 14 trials). These results were robust and remained significant after sensitivity analysis. Study heterogeneity was generally high. As for physical exercise modalities, aerobic exercise, but not other modalities, increased adiponectin and reduced leptin levels. In conclusion, physical exercise and, specifically, aerobic exercise, leads to higher adiponectin and lower leptin levels in prediabetic and diabetic adults. However, cautious interpretation of current findings is warranted.

Exercise decreases CLK2 in the liver of obese mice and prevents hepatic fat accumulation.

The accumulation of fatty acids in the liver associated with obesity condition is also known as nonalcoholic fatty liver disease (NAFLD). The impaired fat oxidation in obesity condition leads to increased hepatic fat accumulation and increased metabolic syndrome risk. On the other hand, physical exercise has been demonstrated as a potent strategy in the prevention of NAFLD. Also, these beneficial effects of exercise occur through different mechanisms. Recently, the Cdc2-like kinase (CLK2) protein was associated with the suppression of fatty acid oxidation and hepatic ketogenesis. Thus, obese animals demonstrated elevated levels of hepatic CLK2 and decreased fat acid oxidation. Here, we explored the effects of chronic physical exercise in the hepatic metabolism of obese mice. Swiss mice were distributed in Lean, Obese (fed with high-fat diet during 16 weeks) and Trained Obese group (fed with high-fat diet during 16 weeks and exercised (at 60% exhaustion velocity during 1 h/5 days/week) during 8 weeks. In our results, the obese animals showed insulin resistance, increased hepatic CLK2 content and increased hepatic fat accumulation compared to the Lean group. Otherwise, the chronic physical exercise improved insulin resistance state, prevented the increased CLK2 in the liver and attenuated hepatic fat accumulation. In summary, these data reveal a new protein involved in the prevention of hepatic fat accumulation after chronic physical exercise. More studies can evidence the negative role of CLK2 in the control of liver metabolism, contributing to the improvement of insulin resistance, obesity, and type 2 diabetes.

Association of physical activity with cognition, metacognition and academic performance in children and adolescents: a protocol for systematic review and meta-analysis

IntroductionSchools provide a relevant context for improving children's and adolescents’ physical and mental health by increasing physical activity during school hours and/or beyond. The interest in the relationship between physical...

Physical exercise and vascular endothelial growth factor (VEGF) in elderly: A systematic review

The aim of this study was to conduct a systematic review of studies that verified the effects of physical exercise on vascular endothelial growth factor (VEGF) in elderly. MethodologyThe bibliographic search was conducted in five database, from 1990 to 2013, with the following keywords and boolean operators: physical exercise OR physical exercise OR physical therapy OR exercise OR training AND VEGF OR vascular endothelial growth factor AND aged OR older OR elderly. The inclusion criteria were: (1) sample including elderly with average age of 60; (2) studies that verified the effects of acute exercise; (3) studies that verified the effects of chronic physical exercise; (4) studies with humans; (5) randomized controlled trials, randomized non-controlled trials, non-randomized controlled trials, non-randomized and non-controlled trials; (6) assessment of VEGF peripheral concentrations. ResultsTen studies were selected, and that four of them verified an increase of VEGF concentrations after practicing physical exercise and six studies did not verify any change on VEGF concentrations. ConclusionDifferent populations found in this study and the different exercise protocols applied in the studies of this review make it difficult to establish parameters of what would be the best type of exercise to promote an increase on the concentrations of VEGF in the elderly. Therefore, we suggest that further studies can be performed, so that we can establish some recommendations for this population.

Asma, estrés oxidativo y ejercicio físico: revisión de la literatura

ObjectiveTo describe the relationship between oxidative stress present in bronchial asthma and the role of acute and chronic effects of physical exercise on airway inflammation and antioxidant defense system balance based on the current scientific literature on this subject. Search strategyRelevant scientific articles were searched in the PubMed, Scopus, Embase and Ovid databases. Study selectionWe used international articles published in English, Portuguese or Spanish that provided an objective approach within the epidemiological, physiopathological and physiological and biochemical context of the article. Synthesis of resultsAsthmatic bronchial inflammation is directly associated with the execution of physical exercise, endogenous oxidant production and the antioxidant defense system. ConclusionsPhysical exercise exacerbates bronchial constriction and increases oxidative stress. However, in the long term, it provides anti-inflammatory and antioxidant enzyme adaptations. The number of studies that describe the antioxidant adaptations in asthma is ephemeral.

Effects of chronic physical exercise on the electrical activation of myocardium during ventricular fibrillation. Study of the involvement of intrinsic cholinergic neurons. An experimental research

Effects of chronic physical exercise on the electrical activation of myocardium during ventricular fibrillation. Study of the involvement of intrinsic cholinergic neurons. An experimental research

Effect of Physical Exercise on the Level of DNA Damage in Chronic Obstructive Pulmonary Disease Patients

This study assessed the chronic effects of physical exercise on the level of DNA damage and the susceptibility to exogenous mutagens in peripheral blood cells of chronic obstructive pulmonary disease (COPD) patients. The case-control study enrolled COPD patients separated into two groups (group of physical exercise (PE-COPD; n=15); group of nonphysical exercise (COPD; n=36)) and 51 controls. Peripheral blood was used to evaluate DNA damage by comet assay and lipid peroxidation by measurement of thiobarbituric acid reactive species (TBARS). The cytogenetic damage was evaluated by the buccal micronucleus cytome assay. The results showed that the TBARS values were significantly lower in PE-COPD than in COPD group. The residual DNA damage (induced by methyl methanesulphonate alkylating agent) in PE-COPD was similar to the controls group, in contrast to COPD group where it was significantly elevated. COPD group showed elevated frequency of nuclear buds (BUD) and condensed chromatin (CC) in relation to PE-COPD and control groups, which could indicate a deficiency in DNA repair and early apoptosis of the damaged cells. We concluded that the physical exercise for COPD patients leads to significant decrease of lipid peroxidation in blood plasma, decrease of susceptibility to exogenous mutagenic, and better efficiency in DNA repair.

Effets positifs de l'exercice physique chronique sur les fonctions cognitives des seniors : bilan et perspectives

De nombreuses etudes epidemiologiques, transversales et interventionnelles presentent un faisceau d’arguments convaincants en faveur d’un effet prophylactique de la pratique reguliere d’une activite physique sur la sante cerebrale et cognitive des seniors. Trois meta-analyses, rassemblant les donnees d’une cinquantaine d’essais controles randomises, montrent qu’il existe bien une relation de cause a effet entre l’exercice physique chronique et les performances cognitives des personnes âgees, et que l’amplitude de l’effet est faible a moderee. Differentes fonctions cognitives telles que la vitesse de traitement de l’information, les fonctions executives ou la memoire declarative semblent fonctionner de maniere plus efficiente sous l’effet d’un programme de 6 mois combinant 45 minutes d’exercices physiques aerobies d’intensite moderee a elevee (marche soutenue, jogging) et d’exercices de musculation trois fois par semaine ou plus. Plusieurs mecanismes neurophysiologiques, impliquant differents facteurs neurotrophiques liberes au cours de l’exercice et augmentant la plasticite cerebrale, pourraient expliquer ce phenomene. Enfin, la relation entre la sante cardio-respiratoire et la sante cerebrale ou cognitive semble etre moderee par differents facteurs individuels en lien avec les habitudes de vie des seniors (regime alimentaire, reserve cognitive accumulee au cours de la vie) ou leur patrimoine genetique (polymorphismes des genes de l’apolipoproteine E, de la catechol-O-methyltransferase et du facteur neurotrophique derive du cerveau).

Effects of Dietary Restriction and Chronic Physical Exercise on Adipose Tissue Proinflammatory Cytokines Expression

Food restriction associated with chronic physical exercise is a common practice among female professional athletes. Some studies have shown that both intense exercise and low energy availability affect the cytokine production profile of the white adipose tissue (WAT), decreasing immune cell infiltration and the expression of genes encoding inflammatory molecules. However, the combined effects of chronic physical exercise and food restriction upon these parameters have never been described. PURPOSE: To determine the effect of exercise training and food restriction on WAT inflammation. METHODS: 24 female Sprague-Dawley rats were randomly assigned into four groups: sedentary (S), sedentary with restricted food intake (SR), trained (T) and trained with restricted food intake (TR) groups. Trained rats ran on a treadmill twice/day (1h), 5 days/wk for 5 wk (85%VO2max). The food restricted groups consumed 50% of food intake of controls animals. TNF-alpha and IL-1b concentration in WAT were assessed by ELISA. RESULTS: A reduction in relative WAT weight (percentage of total body weight) in TR (4.0 fold; p<0.001) when compared with T was found. Relative WAT weight of T was higher than S (p<0.01). IL-1b concentration was markedly decreased 6-fold (p<0.001) in TR when compared to other groups, while there was a tendency to reduced TNF-alpha concentration (7-fold, p=0.06) in TR when compared to T. CONCLUSION: TNF-alpha directly stimulates lipolysis and IL-1b release by adipocytes in an autocrine/paracrine manner. Our findings show that chronic exercise and food restriction induce, together decrease TNF-alpha and IL-1b in WAT, reducing the inflammatory profile in the tissue.

Chronic exercise decreases cytokine production in healthy rat skeletal muscle

Skeletal muscle is the source of pro- and anti-inflammatory cytokines, and recently, it has been recognized as an important source of interleukin-6 (IL-6). Acute physical exercise is known to induce a pro-inflammatory cytokine profile in the plasma. However, the effect of chronic physical exercise in the production of pro- and anti-inflammatory cytokines by the skeletal muscle has never been examined. We assessed IL-6, TNF-alpha, IL-1beta and IL-10 levels in the skeletal muscle of rats submitted to endurance training. Animals were randomly assigned to either a sedentary group (S, n = 7) or an endurance exercise trained group (T, n = 8). Trained rats ran on a treadmill for 5 days week(-1) for 8 weeks (60% VO(2max)). Detection of IL-6, TNF-alpha, IL-1beta and IL-10 protein expression was carried out by ELISA. We found decreased expression of IL-1beta, IL-6, TNF-alpha and IL-10 (28%, 27%, 32% and 37%, respectively, p < 0.05) in the extensor digital longus (EDL) from T, when compared with S. In the soleus, IL-1beta, TNF-alpha and IL-10 protein levels were similarly decreased (34%, 42% and 50%, respectively, p < 0.05) in T in relation to S, while IL-6 expression was not affected by the training protocol. In conclusion, exercise training induced decreased cytokine protein expression in the skeletal muscle. These data show that in healthy rats, 8-week moderate-intensity aerobic training down regulates skeletal muscle production of cytokines involved in the onset, maintenance and regulation of inflammation, and that the response is heterogeneous according to fibre composition.

Endurance training induces depot-specific changes in IL-10/TNF-α ratio in rat adipose tissue

White adipose tissue (WAT) is the source of pro- and anti-inflammatory cytokines and recently, it has been recognized as an important source of interleukin 10 (IL-10). Acute physical exercise is known to induce an anti-inflammatory cytokine profile, however, the effect of chronic physical exercise on the production of IL-10 by WAT has never been examined. We assessed IL-10 and TNF-α concentration in WAT of rats engaged in endurance training. Animals were randomly assigned to either a sedentary control group (S, n = 7) or an endurance trained group (T, n = 8). Trained rats ran on a treadmill 5 days/wk for 8 wk (55–65% VO 2max). Detection of IL-10 and TNF-α protein and mRNA expression, as well as the gene expression of PPAR-γ, and immunocytochemistry to detect mononuclear phagocytes were carried out. A reduction in absolute retroperitoneal adipose tissue (RPAT) weight in T (44%; p < 0.01), when compared with S was observed. IL-10 concentration was increased (1.5-fold, p < 0.05), to a higher extent than that of TNF-α (66%, p < 0.05) in the mesenteric adipose tissue (MEAT) of the trained group, while no change related to training was observed in RPAT. In MEAT, IL-10/TNF-α ratio was increased in T, when compared with S (30%; p < 0.05). PPAR-γ gene expression was increased in T (1.1-fold; p < 0.01), when compared with S in the same adipose depot. No monocyte infiltration was found. In conclusion, exercise training induced increased IL-10 expression in the mesenteric depot, resulting in a modified IL-10/TNF-α ratio. We also conclude that WAT presents a depot-specific response to endurance training regarding the studied aspects.

The effect of chronic physical exercise on succinic dehydrogenase activity in the heart muscle of old rats

Succinic dehydrogenase (SDH) activity, preferentially evidenced by cytochemical methods, has been measured by computer-assisted morphometry in the heart muscle of old sedentary and age-matched animals chronically undergone physical exercise (20 min, twice a day, 5 days a week). The area of the SDH-positive mitochondria (MA) and the overall area of the cytochemical precipitates due to SDH activity (PA) were semiautomatically measured and the ratios PA/MA as well as MA/overall myocardial tissue area analysed (MA/TA) were the parameters taken into account. No significant difference was found between the two groups investigated as regards PA/MA, whereas the MA/TA value is significantly increased in the animals undergone physical training. The present findings document that chronic physical exercise significantly increases the overall mitochondrial area involved in energy provision in the old myocardial tissue. Considering that myocardial function highly relies on mitochondrial metabolism, our results support a beneficial effect of chronic physical exercise on the old heart muscle.

Chronic physical exercise reduces anxiety-like behavior in rats.

While many individuals with anxiety disorders receive drug therapy, many do not respond or adversely respond to drugs. An alternative treatment, exercise, has been shown to relieve negative feelings and induce positive shifts in mood. The purpose of this study was to establish an animal model to specifically test the effects of chronic physical exercise on anxiety-related behaviors. Thirty-two male Sprague Dawley rats were divided into two groups: runners (R) and nonrunners (NR). Runners ran on a treadmill for 45 minutes a day, five days a week, for ten weeks at a moderate intensity. Nonrunners remained in their cages in the treadmill room during the running period and were handled for an equal amount of time. After ten weeks of training, two behavioral tests were administered including the elevated plus maze and open field tests. Results comparing R and NR showed higher responses by R in percent open arm time and center square time during the elevated plus maze test, as well as in number of entries into the center, number of rears, and lower fecal boli count during the open field test, p < 0.05. In addition, there were no differences in total activity levels between groups as indicated by similar closed arm entries in the elevated plus maze test and total lines crossed in the open field test. These results indicate that treadmill training reduces anxiety-like behaviors in two animal tests of anxiety, without a significant change in total activity levels. These data are in support of treadmill training as a model to test the anxiolytic effects of exercise.

A neural network confirms that physical exercise reverses EEG changes in depressed rats

The use of an artificial neural network (ANN) system to differentiate the EEG power density spectra in depressed from normal rats was tried. The beneficial effects of chronic physical exercise in reducing the effects of stress and therefore depression was also to be tested in animals by the same method. In this study, rats were divided into 4 groups, subjected to (i) chronic stress (D group); (ii) chronic exercise by treadmill running (EO group); (iii) exercise with stress (ES group) and (iv) handling (C group). The prefrontal cortical EEG, EMG and EOG were recorded simultaneously on paper and the digitized EEG signals were also stored in the hard-disk of a PC-AT through an ADC. After filtering the digitize signals, the EEG power spectra were calculated by an FFT routine. Three successive 4 s artefact-free epochs were averaged. The REM and NREM sleep periods as well as the awake period signals were analyzed separately. The FFT values from each of the 3 states, in the 4 groups of animals were tested by an ANN with 30 first layer neurons and a 2nd layer of a majority-vote-taker. The ANN could distinguish the depressed from the normal rats' EEG very well in REM (99%) sleep, NREM (95%) sleep and awake (81%) states. In most of the cases it identified the exercised rats' EEG as normal.