Weeks Of Moderate Exercise Research Articles

Enhancing cognitive performance and mitigating dyslipidemia: the impact of moderate aerobic training on sedentary older adults

BackgroundThe present study aimed to evaluate the effects of 24 weeks of moderate aerobic exercise on lipids and lipoprotein levels; Lipo (a) markers, and their association with cognitive performance in healthy older adults.MethodsA total of 150 healthy subjects (100 males and 50 females; age range: 65–95 years) were recruited for this study. Based on the LOTCA test score, subjects were classified into two groups: the control group (n = 50) and the cognitive impairment group (n = 100). Cognitive functioning, leisure-time physical activity (LTPA), lipid profile, total cholesterol, TG, HDL-c, LDL-C, and lipo(a) were assessed at baseline and post-24-week aerobic exercise interventions using LOTCA battery, pre-validated Global Physical Activity Questionnaire (GPAQ) version II, colorimetric, and immunoassay techniques, respectively.ResultsSignificant improvements in cognitive function and modulation in lipid profile and lipoprotein (a) markers were reported in all older subjects following 24 weeks of moderate exercise. LOTCA-7-sets scores significantly correlated with physical activity status and the regulation of lipids and Lipo (a) markers. Physically active persons showed higher cognitive performance along with a reduction in the levels of T-Cholest., TG, LDL-C, Lipo (a), and an increase in the levels of HDL-C and aerobic fitness VO2max compared with sedentary participants. Cognitive performance correlated positively with increased aerobic fitness, HDL-C, and negatively with T-Cholest., TG, LDL-C, and Lipo (a). However, a significant increase in the improvement of motor praxis, vasomotor organization, thinking operations, attention, and concentration were reported among older adults.ConclusionsThe study findings revealed that supervised moderate aerobic training for 24 weeks significantly enhances cognitive functions via mitigating older adults’ lipid profiles and lipoprotein (a). Cognitive performance is positively correlated with aerobic fitness and HDL-C level and negatively with T-Cholest., TH, LDL-C, and Lipo (a).

Exercise During the First Trimester of Pregnancy and the Risks of Abnormal Screening and Gestational Diabetes Mellitus.

To estimate the effects of exercise during the first trimester on the risks of abnormal screening and gestational diabetes mellitus (GDM). Data come from PETALS, a prospectively followed pregnancy cohort (n = 2,246, 79% minorities) receiving care at Kaiser Permanente Northern California. A Pregnancy Physical Activity Questionnaire was used to assess exercise. Glucose testing results for screening and diagnostic tests were obtained from electronic health records. Inverse probability of treatment weighting and targeted maximum likelihood with data-adaptive estimation (machine learning) of propensity scores and outcome regressions were used to obtain causal risk differences adjusted for potential confounders, including prepregnancy BMI, exercise before pregnancy, and gestational weight gain. Exercise was dichotomized at 1) the cohort's 75th percentile for moderate- to vigorous-intensity exercise (≥13.2 MET-h per week or ≥264 min per week of moderate exercise), 2) current recommendations (≥7.5 MET-h per week or ≥150 min per week of moderate exercise), and 3) any vigorous exercise. Overall, 24.3% and 6.5% had abnormal screening and GDM, respectively. Exercise meeting or exceeding the 75th percentile decreased the risks of abnormal screening and GDM by 4.8 (95% CI 1.1, 8.5) and 2.1 (0.2, 4.1) fewer cases per 100, respectively, in adjusted analyses. Exercise reduces the risks of abnormal screening and GDM, but the amount needed to achieve these risk reductions is likely higher than current recommendations. Future interventions may consider promoting ≥38 min per day of moderate-intensity exercise to prevent GDM.

Physical activity impact on motor development and oxidative stress biomarkers in school children with intellectual disability.

OBJECTIVE Lower physical fitness and poor motor performance were shown to be linked with higher levels of oxidative stress in children and adolescents with intellectual disabilities. Therefore, a moderate aerobic exercise for 12-weeks was performed to evaluate the effects of physical activity scores on motor functions, oxidative stress, and intelligence quotients (IQ) in school children with intellectual disability. METHODS A total of 65 school children aged (12-18 Yrs) were randomly included in this study. Intellectual disability (ID),motor skills,physical fitness(VO2max), total energy expenditure (TEE), MDA, 8-OHdG, TAC, NO, and total oxidative stress(OS)were assessed using pre-validated WISC-IQ score test, BOT-2 test, PA questionnaire, and immunoassay techniques respectively. RESULTS WISC-IQ and BOT-2 set scores of intellectual and motor skills performance showed a significant correlation with physical activity status and the regulation of oxidative stress-free radicals in school children with mild and moderate ID following 12 weeks of moderate exercise. The intellectual and motor skills performance of the participants correlated positively with the increase in TAC activity and physical fitness scores and negatively with MDA, 8-OHdG, NO, and Total-OS, respectively. Stepwise multiple regression analysis of the demographic, physical status and oxidative stress parameters explained around78.0 to 93.4 % of intellectual disability variation among schoolchildren. CONCLUSION Moderate aerobic training for12 weeks has a positive impact on improving intellectual ability of schoolchildren with ID via modulating redox status, improves physical fitness, and motor skills proficiency.

The effect of endurance exercise and methadone on μ-opioid receptor gene expression in morphine-dependent rats following withdrawal syndrome

Opiate dependence (e.g., morphine) is one of the most important problems affecting human health. Morphine reduces the irritability of neurons in the pain pathway by attaching to some such opioid receptors such as μ receptor (MOR). Exercise can improve destructions due to opiate dependence in many of the body organs including nerve systems. Thus, the aim of this study was to investigate the effect of endurance exercise training (8 weeks of moderate exercise) and methadone on μ-opioid receptor gene (OPRM1) expression in morphine-dependent rats following withdrawal syndrome. 48 male Wistar rats (9 weeks; weight: 295 ± 20 g) were kept as four animals per cage. The animals were selected and divided randomly into six subgroups of eight individuals: control (C), healthy exercise (TN), control addicts (CTM), addicts treated with methadone (MM), addicts treated with exercise (TM), and addicts treated with methadone plus exercise (TMM). In the present study, oral administration of morphine was used to induce dependence. Interventional therapy protocol also included a combination of methadone and a chronic aerobic exercise program. Changes in MOR gene expression levels were evaluated by RT-qPcR. Results showed a significant increase in MOR gene expression in the treatment with endurance training (TM) compared to the control group (C) (p < 0.05).Also, a significant increase in MOR gene expression was observed in the treatment group with methadone (MM) versus the normal group (C) (p < 0.05). It seems that physical activity, especially running on treadmill (endurance exercise) in animal model, can be considered as a non-medication and complementary therapy at various stages of dependence and addiction processes. However, further studies are needed especially in human sample.

Abstract P154: Healthy Lifestyle and Risk of Incident Heart Failure With Preserved and Reduced Ejection Fraction in Postmenopausal Women: The Women’s Health Initiative Study

Background: Heart failure (HF) is a growing health concern in the United States. Lifestyle risk factors including diet, physical activity, cigarette smoking, and body mass index (BMI), have been shown to be independently and jointly associated with incident heart failure. However, these associations have not been evaluated for HF subtypes, HF with reduced ejection fraction (HFrEF) or HF with preserved ejection fraction (HFpEF). Objective: To assess the combined associations of diet, physical activity, cigarette smoking, and BMI with risk of HFpEF and HFrEF subtypes. Methods: 39,893 postmenopausal women aged 50-79, without self-reported HF at baseline, were included in this analysis. A lifestyle score was created following a similar method previously used in WHI, defining the following healthy criteria: high diet quality (Alternate Healthy Eating Index quintile 4 or 5), being physically active (more than 150 minutes per week of moderate exercise or 75 minutes per week of vigorous exercise or equivalent combination), not a current cigarette smoker, and BMI between 18.5 and 25 kg/m 2 . Women received 1 point for each healthy criterion that was met, and points were summed to obtain the healthy lifestyle score, ranging in value from 0 (least healthy) to 4 (most healthy). Trained adjudicators determined cases of incident heart failure through 2018, defining HFpEF as EF≥45% and HFrEF as EF&lt;45%. Results: Over a mean follow-up of 14.5 years, 2426 HF incident hospitalized cases were documented and confirmed, classifying 1345 cases as HFpEF and 685 cases as HFrEF. Healthy lifestyle was strongly associated with a decreased risk of both HFpEF and HFrEF (Table). Conclusion: Findings suggest that a healthy lifestyle may be associated with decreased risk of HF subtypes among postmenopausal women. Results from this research provide a better understanding of the role of modifiable lifestyle factors in each of the HF subtypes, allowing for the development of more targeted primary and secondary prevention strategies specific to HFpEF and HFrEF.

Exercise Training-induced Modulation in Microenvironment of Rat Mammary Neoplasms.

Despite the importance attributed to exercise training in the breast cancer (BC) continuum, the underlying mechanisms modulating tumor behavior are unknown. We evaluated the effects of long-term moderate-exercise in the development of mammary tumors, and studied the microenvironment of infiltrative lesions, the amount of connective tissue, and balance between cellular proliferation/death.Fifty Sprague-Dawley rats, randomly assigned into four groups: two control groups (sedentary and exercised) and two models of BC groups (sedentary and exercised) induced by N-methyl-N-nitrosoureia (MNU), were sacrificed after 35 weeks of moderate-exercise, and all perceptible tumors were removed for histological and immunohistochemistry analysis.The median number of infiltrative-lesions per animal was lower in the MNU exercised animals (p=0.02). More than one histological pattern was identified, and papillary carcinoma was the most frequent in both groups. Within infiltrative-lesions, the number of immunopositive cells per μm2 of Ki67 was lower in exercised animals (p=0.002). This presents increased cell death per μm2 (p=0.019). Tumors from sedentary animals had a higher expression of collagen deposition (p=0.027).Long-term moderate-exercise has beneficial effects in tumor development with a diminished prevalence of malignancy. Within infiltrative-lesions, moderate-exercise improves the balance between cell-proliferation and cell-death with decreased connective tissue that suggests lower tumor aggressiveness.

Moderate exercise ameliorates dysregulated hippocampal glycometabolism and memory function in a rat model of type 2 diabetes.

Type 2 diabetes is likely to be an independent risk factor for hippocampal-based memory dysfunction, although this complication has yet to be investigated in detail. As dysregulated glycometabolism in peripheral tissues is a key symptom of type 2 diabetes, it is hypothesised that diabetes-mediated memory dysfunction is also caused by hippocampal glycometabolic dysfunction. If so, such dysfunction should also be ameliorated with moderate exercise by normalising hippocampal glycometabolism, since 4weeks of moderate exercise enhances memory function and local hippocampal glycogen levels in normal animals. The hippocampal glycometabolism in OLETF rats (model of human type 2 diabetes) was assessed and, subsequently, the effects of exercise on memory function and hippocampal glycometabolism were investigated. OLETF rats, which have memory dysfunction, exhibited higher levels of glycogen in the hippocampus than did control rats, and breakdown of hippocampal glycogen with a single bout of exercise remained unimpaired. However, OLETF rats expressed lower levels of hippocampal monocarboxylate transporter 2 (MCT2, a transporter for lactate to neurons). Four weeks of moderate exercise improved spatial memory accompanied by further increase in hippocampal glycogen levels and restoration of MCT2 expression independent of neurotrophic factor and clinical symptoms in OLETF rats. Our findings are the first to describe detailed profiles of glycometabolism in the type 2 diabetic hippocampus and to show that 4weeks of moderate exercise improves memory dysfunction in type 2 diabetes via amelioration of dysregulated hippocampal glycometabolism. Dysregulated hippocampal lactate-transport-related glycometabolism is a possible aetiology of type-2-diabetes-mediated memory dysfunction.

Effect of Moderate Exercise on Serum Interferon-Gamma and Interleukin-17 Levels in the Morphine Withdrawal Period.

BackgroundDrug addiction triggers the infliction of a variety of diseases. Various subjects have indicated that during the withdrawal syndrome period, the immune system is weakened.ObjectivesThis study aimed to investigate the changes in serum levels of interferon-gamma (IFN-γ) and interleukin-17 (IL-17) during the morphine withdrawal syndrome induced by 8 weeks of moderate exercise and their effects on the immune system function.Materials and MethodsTwenty-four male Wistar rats (220 ± 10 g) were divided into four groups (n = 6): healthy control (HC), addicted control (AC), healthy trained (HT), and addicted trained (AT) groups. AC and AT groups were made addicted to morphine sulfate (0.4 mg/mL) in 21 days. To ensure their dependence on morphine, naloxone (3 mg/kg, i.p.) was injected into the body of a number of the rats. HT and AT groups were made to run on a treadmill 5 days per week for 8 weeks while time and speed gradually increased. Both prior to the exercises and 24 hours after the last training session, blood samples were collected from all the animals, and serum IFN-γ and IL-17 serum levels were measured using the ELISA method. This research was performed at the Bu-Ali Sina University, Hamadan, Iran.ResultsAfter 8 weeks of exercise, a significant increase was observed in the serum IFN-γ level in the HT group (251.17 ± 13.045) in comparison with the HC group (234 ± 12.884) (P = 0.045). Furthermore, the serum IFN-γ level in the AT group (218.33 ± 5.164) in comparison to the AC group (190.67 ± 8.477) showed a significant increase (P = 0.000). In addition, the serum level of IFN-γ in the HT group showed a significant increase compared to the AT group (P = 0.000). After 8 weeks of exercise, there was a significant decrease in the serum IL-17 level in the HT group (22.67 ± 4.46) compared with the HC group (38.17 ± 7.68) (P = 0.005). In addition, a significant decrease was observed in serum IL-17 in the AT group (42.17 ± 7.41) in comparison with the AC group (57.17 ± 7.83) (P = 0.007). In addition, the serum IL-17 level in the HT group significantly decreased in comparison with the AT group (P = 0.001).ConclusionsModerate exercise for 8 weeks increased the IFN-γ and decreased the IL-17 serum levels in the morphine-dependent rats. For this reason, this type of exercise can improve the function of the immune system during morphine withdrawal syndrome.

Correlation between bone mineral density and serum trace elements in response to supervised aerobic training in older adults.

BackgroundLife style and physical activity play a pivotal role in prevention and treatment of osteoporosis. The mechanism for better bone metabolism and improvement of physical disorders is not clear yet. Trace minerals such as Ca, Mn, Cu, and Zn are essential precursors for most vital biological process, especially those of bone health.ObjectiveThe main target of this study was evaluating the effective role of supervised aerobic exercise for 1 hour/day, 3 days/week for 12 weeks in the functions of trace elements in bone health through measuring bone mineral density (BMD), osteoporosis (T-score), bone markers, and trace element concentrations in healthy subjects aged 30–60 years with age average of 41.2±4.9.MethodsA total of 100 healthy subjects (47 males, 53 females; age range 30–60 years) were recruited for this study. Based on dual-energy x-ray absorptiometry (DEXA) scan analysis, the participants were classified into three groups: normal (n=30), osteopenic (n=40), and osteoporotic (n=30). Following, 12 weeks of moderate aerobic exercise, bone-specific alkaline phosphatase (BAP), BMD, T-score, and trace elements such as Ca, Mn, Cu, and Zn were assessed at baseline and post-intervention.ResultsSignificant improvement in serum BAP level, T-score, and BMD were observed in all participants following 12 weeks of moderate exercise. Participants with osteopenia and osteoporosis showed significant increase in serum Ca and Mn, along with decrease in serum Cu and Zn levels following 12 weeks of aerobic training. In control group, the improvements in serum trace elements and body mass index were significantly linked with the enhancement in the levels of BAP, BMD hip, and BMD spine. These results supported the preventive effects of moderate exercise in healthy subjects against osteoporosis. In both sexes, the changes in serum trace elements significantly correlated (P<0.05) with the improvement in BAP, BMD hip, BMD spine, and body mass index in all groups.ConclusionThe observed changes in the levels of Ca, Mn, Cu, and Zn were shown to be positively correlated with improved bone mass density among control and osteoporosis subjects of both sexes. These results demonstrate that aerobic exercise of moderate intensity might protect bone and cartilage by regulation of body trace elements which are involved in the biosynthesis of bone matrix structures and inhibition of bone resorption process via a proposed anti-free radical mechanism.

Effects of Moderate Aerobic Exercise on Cognitive Abilities and Redox State Biomarkers in Older Adults.

We used a moderate aerobic exercise program for 24 weeks to measure the positive impact of physical activity on oxidative stress and inflammatory markers and its association with cognitive performance in healthy older adults. A total of 100 healthy subjects (65–95 Yrs) were randomly classified into two groups: control group (n = 50) and exercise group (n = 50). Cognitive functioning, physical activity score, MDA, 8-OHdG, TAC, and hs-CRP were assessed using LOTCA battery, prevalidated PA questionnaire, and immunoassay techniques. LOTCA 7-set scores of cognitive performance showed a significant correlation with physical activity status and the regulation of both oxidative stress free radicals and inflammatory markers in all older subjects following 24 weeks of moderate exercise. Physically active persons showed a higher cognitive performance along with reduction in the levels of MDA, 8-OHdG, and hs-CRP and increase in TAC activity compared with sedentary participants. Cognitive performance correlated positively with the increase in TAC activity and physical fitness scores and negatively with MDA, 8-OHdG, and hs-CRP, respectively. There was a significant improvement in motor praxis, vasomotor organization, thinking operations, and attention and concentration among older adults. In conclusion, moderate aerobic training for 24 weeks has a positive significant effect in improving cognitive functions via modulating redox and inflammatory status of older adults.

Biphasic response of cardiodynamic adaptations to swimming exercise in rats.

The aim of research was to assess exercise-induced changes in mechanics of hearts isolated from rats, as well as time-course of those changes. Wistar rats (n = 42) were divided into control, moderately trained (swimming 1 hour, 5 days a week for 9 or 12 weeks) and strenuously trained (swimming 2, 3 and 4 times a day for an hour in weeks 10, 11 and 12, respectively) groups. After sacrificing, hearts (weight: 1480.82 ± 145.38 mg) were isolated and perfused on a Langendorff apparatus. Coronary perfusion pressure (CPP) was gradually increased (from 40 to 120 cm H(2)O) in order to establish coronary autoregulation. Parameters of cardiac contractility were recorded: maximum and minimum rate of change of pressure in the left ventricle (dp/dt max and dp/dt min), systolic and diastolic left ventricular pressure (SLVP and DLVP), heart rate (HR) and coronary flow (CF). Nine weeks of moderate exercise induced slight depression of coronary function (decrease of dp/dt max, dp/dt min, SLVP and DLVP), while 3 additional weeks of moderate training improved hearts function, but not to the extent that the strenuous training program did. The results of our study add evidence about beneficial effects of regular moderate exercise on heart, and furthermore, show that exercising frequently, if the intensity stays within moderate range, may not have detrimental effects on cardiodynamics.

Short-term moderate exercise provides long-lasting protective effects against metabolic dysfunction in rats fed a high-fat diet.

A sedentary lifestyle and high-fat feeding are risk factors for cardiometabolic disorders. This study determined whether moderate exercise training prevents the cardiometabolic changes induced by a high-fat diet (HFD). Sixty-day-old rats were subjected to moderate exercise three times a week for 30 days. After that, trained rats received a HFD (EXE-HFD) or a commercial normal diet (EXE-NFD) for 30 more days. Sedentary animals also received the diets (SED-HFD and SED-NFD). Food intake and body weight were measured weekly. After 120 days of life, analyses were performed. Data were analysed with two-way ANOVA and the Tukey post-test. Body weight gain induced by HFD was attenuated in trained animals. HFD reduced food intake by approximately 30% and increased body fat stores by approximately 75%. Exercise attenuated 80% of the increase in fat pads and increased 24% of soleus muscle mass in NFD animals. HFD induced a hyper-response to glucose injection, and exercise attenuated this response by 50%. Blood pressure was increased by HFD, and the beneficial effect of exercise in reducing blood pressure was inhibited by HFD. HFD increased vagal activity by 65% in SED-HFD compared with SED-NFD rats, and exercise blocked this increase. HFD reduced sympathetic activity and inhibited the beneficial effect of exercise on ameliorating sympathetic activity. Four weeks of moderate exercise at low frequency was able to prevent the metabolic changes induced by a HFD but not the deleterious effects of diet on the cardiovascular system.

Moderate Exercise and Bright Light Treatment in Overweight and Obese Individuals

Increased physical activity is important given the concern over the growing rates of obesity. The aim of this study is to conduct a controlled investigation of the effects of bright light therapy and exercise on weight loss and body composition in overweight and obese individuals. Twenty-five overweight and obese subjects were assigned to 6 weeks of moderate exercise with or without bright light treatment. Outcome measure included changes in body mass and body composition and ratings of mood, seasonality, and sleep. Body weight decreased significantly with exercise in subjects in the light and non-light treatment groups, but the change was not significantly different between the groups. Similar results were found for BMI. With exercise, body fat decreased significantly only in the light treatment group. There was a significant effect of the interaction of group by time on body fat composition, but the group by time interaction failed to reach statistical significance for body weight and BMI. Mood scores improved significantly with exercise in the light group, but no significant changes were noted regarding sleep. This preliminary study is the first to show that addition of bright light treatment to a 6-week moderate exercise program can alter body composition by significantly reducing body fat. The reduction in body fat mass is of particular importance, because visceral fat has been particularly implicated as a major factor in the development of the metabolic syndrome. This study is an important step toward finding ways to maximize the effects of exercise.

Exercise training reduces fatty acid availability and improves the insulin sensitivity of glucose metabolism

It is not known whether the beneficial effects of exercise training on insulin sensitivity are due to changes in hepatic and peripheral insulin sensitivity or whether the changes in insulin sensitivity can be explained by adaptive changes in fatty acid metabolism, changes in visceral fat or changes in liver and muscle triacylglycerol content. We investigated the effects of 6 weeks of supervised exercise in sedentary men on these variables. We randomised 17 sedentary overweight male subjects (age 50 +/- 2.6 years, BMI 27.6 +/- 0.5 kg/m(2)) to a 6-week exercise programme (n = 10) or control group (n = 7). The insulin sensitivity of palmitic acid production rate (Ra), glycerol Ra, endogenous glucose Ra (EGP), glucose uptake and glucose metabolic clearance rate were measured at 0 and 6 weeks with a two-step hyperinsulinaemic-euglycaemic clamp [step 1, 0.3 (low dose); step 2, 1.5 (high dose) mU kg(-1) min(-1)]. In the exercise group subjects were studied >72 h after the last training session. Liver and skeletal muscle triacylglycerol content was measured by magnetic resonance spectroscopy and visceral adipose tissue by cross-sectional computer tomography scanning. After 6 weeks, fasting glycerol, palmitic acid Ra (p = 0.003, p = 0.042) and NEFA concentration (p = 0.005) were decreased in the exercise group with no change in the control group. The effects of low-dose insulin on EGP and of high-dose insulin on glucose uptake and metabolic clearance rate were enhanced in the exercise group but not in the control group (p = 0.026; p = 0.007 and p = 0.04). There was no change in muscle triacylglycerol and liver fat in either group. Decreased availability of circulating NEFA may contribute to the observed improvement in the insulin sensitivity of EGP and glucose uptake following 6 weeks of moderate exercise.

Exercise: A Key Component of Diabetes Management

Exercise has long been recognized as an essential component of diabetes management. Elliot Joslin once referred to exercise as “the second steed in the diabetic's three-horse chariot,” sharing equal billing with diet and insulin.1 Subsequent generations of diabetes practitioners have established exercise as one of the four cornerstones of care (along with diet, medication, and monitoring) and have come to learn a great deal more about the mechanisms by which exercise is able to provide such profound benefits for physical health. Atherosclerotic vascular disease remains the number one killer of people with diabetes, and research has shown exercise to be of tremendous utility in its treatment. It is known that exercise ameliorates many of the known vascular disease risk factors, favorably influencing levels of blood pressure, LDL cholesterol, HDL cholesterol, triglycerides, and glycemia.2 More recent research suggests that exercise may exert similarly favorable effects on emerging vascular disease risk factors as well, including thrombosis, endothelial function, and levels of C-reactive protein.2,3 Exercise is perhaps the best therapy for the prevention of both type 2 diabetes and the metabolic syndrome. Exercise appears to aid in the loss of visceral fat, quite literally getting to the core of the metabolic syndrome. Results of the Diabetes Prevention Program4 demonstrated that as little as 150 minutes per week of moderate exercise as part of a lifestyle intervention significantly decreased the progression of type 2 diabetes in patients with preexisting impaired glucose tolerance. These findings were comparable to those of the Finnish Diabetes Prevention Study.5 The magic bullet–like ability of exercise to counter much of the metabolic disruption and ensuing pathology occurring in diabetes is beyond remarkable and has understandably led to greater emphasis being placed on the physiological benefits of exercise. Lesser known, and far less celebrated, …

The effects of exercise on iron status and aerobic capacity in moderately exercising adult women

The purpose of this study was to examine the effects of a 10-week moderate exercise on iron status and aerobic capacity of adult women. Seventeen women, 56- to 67-years, served either as controls (no exercise, n = 9) or participated in a supervised exercise program (n = 8). Women in the exercise group cycled on an ergometer three days per week, for 40 minutes at 70 to 75% maximal heart rate for 10 weeks. Pre- and post- (weeks 0 and 11) submaximal treadmill stress tests were obtained. Aerobic capacity was evaluated by heart rate per grade, maximum oxygen capacity, and time to reach 70% maximum heart rate. The results indicated that average heart rate per grade decreased and time to reach 70% max heart rate increased in the exercise group (p < .05) after 10 weeks of moderate exercise training. Iron status as determined by serum ferritin, transferrin saturation, serum iron, total iron binding capacity, hemoglobin and hematocrit was normal and comparable between both groups. Hemoglobin increased (p < .05) after 10 weeks of supervised moderate exercise. The results suggest that 10 weeks of moderate exercise enhances aerobic capacity of older women but does not compromise iron status.

Tentative de mise au point d'un modèle d'entraînement physique reproduisant chez le rat l'équivalent du syndrome de surentraînement

Resume Nous avons soumis des jeunes rats mâles Wistar a un entrainement physique modere (course sur tapis roulant motorise) de 4 semaines (6 j/semaine, 0,5–1 h/j, 20–30 m/min) suivi de 2 semaines supplementaires d'entrainement modere (1 h/j; rats E+, n=5) ou plus intense (4, 6–6, 4 h/j; rats E++, n=6). Les rats E+ et E++ ont ete sacrifies 18 heures apres la derniere seance d'effort epuisant (test mesurant l'endurance maximale), en meme temps que ceux d'un groupe de rats sedentaires (E-, n=6). Les resultats montrent une diminution de l'endurance maximale (>- 12%) lors de la 6e semaine chez les rats E++ (+9% chez les rats E+). De plus, on observe une diminution plus importante de la prise de poids corporel, de la cellularite du thymus et de la viabilite in vitro des splenocytes (cellules immunitaires de la rate) en reponse aux mitogenes (un index des fonctions de l'immunite cellulaire) chez les rats E++ que chez les rats E+ (respectivement, −19% versus −8%, −72% versus −35%, −44% versus −33%) (P 0,05), mais tres superieures a celles des rats E- (P 0,05). En conclusion, les resultats de ce travail indiquent que l'augmentation brutale du volume d'entrainement physique conduit a une diminution de la performance en endurance associee a une alteration de l'immunite cellulaire chez l'animal. Les systemes metabolique (metabolisme du glycogene) et neuroendocrinien (androgene sexuel) ne semblent pas affectes par cet entrainement intensif. Ces modifications immunitaires sont qualitativement distinctes (inverses) de celles observees lors d'un epuisement physique passager. Comme nous n'avons pas encore montre leur caractere durable et comme elles ne permettent que de dresser une description incomplete de l'equivalent animal du syndrome de surentrainement, de nouvelles tentatives de ce type devront etre menees avant de mettre au point un modele de surentrainement satisfaisant chez l'animal.