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Plasma and urinary catecholamines and metabolites during physical exercise in essential hypertension.

The effect of physical exercise on plasma catecholamines and urinary catecholamines and metabolites was studied in 11 patients with established essential hypertension, 5 patients with borderline hypertension, and 9 healthy volunteers. Resting plasma noradrenaline and the changes following exercise were similar in all the investigated groups. Although the resting urinary noradrenaline excretion was similar in patients and in controls, an exaggerated increase of noradrenaline excretion occurred in hypertensive patients during physical work. This finding suggests sympathetic overreactivity in essential hypertension. The increased plasma levels of adrenaline, found in established hypertension, were associated with its diminished urinary clearance. These results imply altered renal handling of adrenaline in essential hypertension. Physical exercise was associated with enhancement of metabolism of noradrenaline to 3-methoxy,4-hydroxy-phenylglycol in all groups of subjects, but the stimulation of this pathway was particularly pronounced in healthy subjects. In essential hypertension, the pattern of urinary excretion of catecholamines and metabolites suggests impaired noradrenaline metabolism during exercise. The only characteristic feature of borderline, as opposed to established hypertension, was the increased urinary excretion of dopamine.

Adult↗

Physical exercise in relation to degree of metabolic control in juvenile diabetics.

Physical exercise is considered to be one of the basic principles in the management of diabetes, but the evidence to support the long-term benefit of exercise in insulin dependent diabetes is limited. The aim of this study was to analyse the influence of physical activity on the degree of metabolic control, and different groups of diabetics were studied, the largest including 143 children and adolescents with an age at onset between 1-16 years (mean +/- S.D. 7.3 +/- 3.9) and duration of diabetes 1-17 years (7.8 +/- 4.6). In the first part of the study there was a highly significant correlation (r = 0.54, p less than 0.001) between degree of physical activity based on a weekly history and index of metabolic control (proportion of daily urine tests without glucosuria), when other factors of importance for metabolic control were kept constant. With a statistical technique it was possible to show that the observed correlation had its direction from physical exercise to degree of metabolic control. The positive correlation between degree of exercise and metabolic control could be confirmed in a follow-up during two other years. However, it was also evident that in many single patients the correlation between degree of physical exercise and metabolic control was rather negative. Several explanations are possible. The importance of adequate insulin treatment for a positive effect of exercise is stressed.

Blood Glucose↗

Modulation of natural killer cell activity in peripheral blood by physical exercise.

The present study was designed to examine the effect of physical exercise on human natural killer (NK) cells. Six healthy volunteers underwent two different acute physical exercise tests with an interval of at least 1 week: (1) 60 min bicycle exercise at 80% of maximal oxygen uptake (VO2max) and (2) 60 min back-muscle training at up to 29% of VO2max; blood samples were collected before and during the last few minutes of exercise, as well as 2 h and 24 h afterwards. The NK cell activity (lysis/fixed number of mononuclear cells) increased during bicycle exercise, dropped to a minimum 2 h later and returned to pre-exercise levels within 24 h. Back-muscle exercise did not significantly influence NK cell activity. Plasma levels of adrenaline, noradrenaline, and cortisol were elevated during bicycling, but not during back-muscle exercise, indicating that exercise intensity is a determinant of NK cell activity. During bicycle exercise the NK cell subset (CD16- cells) of mononuclear cells increased significantly. Furthermore an improved interleukin 2 (IL-2) boosting of the NK cell activity was found during work as compared to IFN-alpha and indomethacin-enhanced NK cell activity. These results indicate that NK cells with a high IL-2 response capacity are recruited to the peripheral blood during exercise. The decreased NK cell activity demonstrated 2 h after work was probably not due to fluctuations in size of the NK cell pool, since the proportion of CD16+ cells was normal. The finding that indomethacin fully restored the suppressed NK cell activity in vitro and the demonstration of a twofold increase in monocyte (CD20+ cells) proportions 2 h after work, strongly indicate that prostaglandins released by monocytes during the heavy physical exercise are responsible for the down-regulation of the NK cells.

Adult↗

Retardation of the age-associated decline of immune functions in aging rats under dietary restriction and daily physical exercise.

Wistar rats were subjected to dietary restriction and daily physical exercise for 21 months, starting from 2 months of age. At the age of 23 months, the rats were sacrificed and examined for various indices including immunological functions. Body weight was almost the same between rats fed ad libitum (Group A) and those (Group B) fed 80% of the diet consumed by Group A. The body weights of Groups A and B were significantly heavier than that of rats (Group C) fed 60% of the diet consumed by Group A and those (Group D) which were subjected to physical exercise and fed 80% of the diet consumed by Group A. Highly proliferative response of T cells to mitogens was observed in 5 out of 13 rats in group D. Some enhancement of B cell proliferation was also observed in the same rats. Present results suggested that enduring physical exercise together with dietary restriction can retard the age-related decrement of immunological functions.

Aging↗

Changes in plasma catecholamine concentrations in patients with coronary heart disease during pacing and physical exercise.

To study the difference in sympathetic activity during pacing the right atrium or during physical exercise in patients with coronary heart disease, we investigated circulating plasma catecholamine concentrations in the coronary sinus and brachial artery radioenzymatically in 11 male patients with well documented coronary artery disease. Heart rate was increased stepwise 20 beats/min from 90 beats/min up to 150 beats/min by pacing the right atrium and physical exercise was performed by increasing work load stepwise by 25 from 25 up to 100 W on an ergometric bicycle. Plasma noradrenaline and adrenaline concentrations were increased significantly only during physical exercise. In addition, there was an increase in arterial-coronary sinus noradrenaline difference during graded physical exercise, whereas no further release of noradrenaline from the myocardium occurred during pacing. An enhanced cardiac sympathetic tone in patients with coronary heart disease is discussed. It is suggested that atrial pacing is not an adequate stimulus evoking an overall increase of cardiac and peripheral sympathetic tone.

Cardiac Pacing, Artificial↗

Strenuous physical exercise inhibits granulocyte activation induced by high altitude.

To test the hypothesis of whether strenuous physical exercise inhibits neutrophils that can get activated by hypobaric hypoxia, we analyzed the effects of both high altitude and strenuous exercise alone and in combination on potentially cytotoxic functions of granulocytes in healthy volunteers (n = 12 men; average age 27.6 yr; range 24-38 yr). To this end, a field study was prospectively performed with an open-labeled within-subject design comprising three protocols. Protocol I (high altitude) involved a helicopter ascent, overnight stay at 3,196 m, and descent on the following day. Protocol II (physical exercise) involved hiking below an altitude of 2,100 m with repetitive ascents amounting to a total ascent to that of protocol III. Protocol III (combination of physical exercise and high altitude) involved climbing from 1,416 to 3,196 m, stay overnight, and descent on the following day. In protocol I, number of granulocytes did not change, but potentially cytotoxic functions of cells (CD18 expression and superoxide production) were early and significantly upregulated. In protocol II, subjects developed granulocytosis, but functions of cells were inhibited. In protocol III, granulocytosis occurred at higher values than those observed under protocol II. Potentially cytotoxic functions of cells, however, were strongly inhibited again. In conclusion, high altitude alone, even moderate in extent, can activate potentially cytotoxic functions of circulating granulocytes. Strenuous physical exercise strongly inhibits this activation, which may give protection from an otherwise inflammatory injury.

Adaptation, Physiological↗

[Effect of single physical exercise on formation, fixation, and reproduction of temporal associations in rats].

The effects of submaximal and maximal physical exercise on the formation, fixation and subsequent reproduction of temporary relations were compared before or immediately after training. Physical exercise before training, that impairs the formation of temporary relations, led to relatively moderate disorders in their fixation and reproduction. During physical exercise immediately after training, disorders of fixation and subsequent reproduction of temporary relations are more pronounced. It is suggested that disorders of the formation and fixation of the temporary relations caused by physical exercise are partially determined by changes in the brain content of biogenic amines.

Animals↗

Physical exercise and immune system function in cancer survivors: a comprehensive review and future directions.

BACKGROUND: There are a limited number of interventions for cancer survivors following completion of primary therapy that might reduce the risk of cancer recurrence and/or secondary malignancies and increase survival times. It has been proposed that physical exercise may be beneficial by enhancing the anticancer immune system response. The purpose of the current article is to: 1) briefly describe the immune system response to tumors, 2) discuss the impact of anticancer therapy on immune system function in cancer survivors, 3) provide a systematic and comprehensive review of the extant literature examining physical exercise and immune system function in cancer survivors, and 4) offer a critical analysis of this literature and outline directions for future research. METHODS: A comprehensive literature search up to March 2001 identified empirical articles that examined the effects of physical exercise training on immune system function in cancer survivors from CD-ROM database searches and manual searches. RESULTS: To the authors' knowledge, six empirical studies published between 1994 and 2000 have examined physical exercise and immune system function in cancer survivors. Overall, four out of six studies reported statistically significant improvements in a number of cancer-related immune system components as a result of exercise. However, there are several limitations that must be considered when interpreting the findings of these studies. These limitations involve the samples, designs, physical exercise interventions, physical fitness assessments, and immunologic assessments. CONCLUSIONS: Additional research is needed to determine if physical exercise in cancer survivors may reduce the risk of cancer recurrence and secondary malignancies and increase survival times.

Adult↗

Physical exercise during pregnancy--physiological considerations and recommendations.

Controversial findings in numerous studies involving physiological and endocrinological parameters indicate that physical exercise during pregnancy is complex and somewhat poorly understood. But despite this reservation, it is safe to say that on the basis of the current state of scientific research in this area, physical exercise is to be recommended during pregnancy so long as women are aware of potential dangers and contraindications. Due to thermoregulatory advantages, the beneficials effects of immersion and its joint protective character "aquatic exercise" can be highly recommended during pregnancy. Psychologically speaking, physical exercise offers a variety of benefits such as the encouragement of cooperation and competition which can be experienced as fun and gratifying. The physiological and psychological benefits of physical exercise are not only available to healthy women, but have also proven to be valuable for the prevention and treatment of illnesses such as gestational diabetes. The activation of large groups of muscles allow for an improved glucose utilization by simultaneously increasing insulin sensitivity.

Body Temperature Regulation↗

Physical exercise and comorbidity. Results from the Fitness and Arthritis in Seniors Trial (FAST).

BACKGROUND AND AIMS: Physical exercise is associated with a lower risk of disability. The impact of comorbidity on the benefits from physical exercise has not been clearly investigated. Elders with comorbidity may benefit from physical exercise to preserve physical function. METHODS: Data are from 435 participants with knee osteoarthritis aged > or = 60 years enrolled in the Fitness and Arthritis in Seniors Trial (FAST), who were randomly assigned to 18-month health educational (HE), weight training (WT), or aerobic exercise (AE) interventions. Comorbidity was defined as the presence of osteoarthritis and > or = 2 clinical conditions. Percent changes in the 6-minute walk test, self-reported disability and knee pain from baseline to 3-, 9-, and 18-month follow-up visits were analyzed according to comorbidity, using analysis of variance. Significances were adjusted using the Bonferroni method. RESULTS: Mean age of the sample was 68.7 years. In participants with comorbidity (n=197), those in the AE intervention showed significant improvement in walking speed, compared to WT and HE groups, since the beginning of follow-up. Subjects with comorbidity in AE and WT groups showed improvement of the disability score at the 3-month follow-up visit compared to those in the HE group. This improvement was maintained at the end of the follow-up by the only AE group compared to the HE one (p=0.06). In participants with comorbidity, the pain score was improved by the AE intervention. CONCLUSIONS: AE and WT interventions improve physical function in individuals with comorbidity. AE improves physical function and knee pain independently of the presence of comorbidity.

Aged↗

[Physical exercise among school children. A nation-wide sociomedical study of 1,671 children 11-15 years of age].

A total of 1,671 children aged 11, 13 and 15 years from a nationwide random sample of schools completed an anonymous questionnaire on their social backgrounds, social networks, health, life satisfaction, and health behaviour. The proportion practising outdoor activities at least three times a week was 57%; 37% did some physical exercise in their leisure time sufficient to make them breathless or sweat at least four times a week; 43% at least four hours a week. Two thirds were active members of a sports club. A minority of 8% did not carry out any physical exercise during their leisure time sufficient to make them breathless or sweat. Boys did more physical exercise than girls irrespective of the measurement of exercise. The most important motives for physical exercise were to improve health, to get in good shape, to have fun, and to make new friends. More than 90% of the children intended to do physical exercise at the age of 20. High intensity of physical activity was associated with high social class, strong social integration in the peer group, easy contact with parents and friends, physical exercise among parents and best friends, high degree of life satisfaction, and good health.

Adolescent↗

Effects of acute physical exercise characteristics on cognitive performance.

The effect of physical exercise on mental function has been widely studied from the beginning of the 20th century. However, the contradictory findings of experimental research have led authors to identify several methodological factors to control in such studies including: (i) the nature of the psychological task; and (ii) the intensity and duration of physical exercise. The purpose of this article is to provide information, from the perspective of performance optimisation, on the main effects of physical task characteristics on cognitive performance. Within this framework, some consistent results have been observed during the last decade. Recent studies, using mainly complex decisional tasks, have provided the research community with clear support for an improvement of cognitive performance during exercise. Diverse contributing factors have been suggested to enhance cognitive efficacy. First, an increase in arousal level related to physical exertion has been hypothesised. Improvement in decisional performance has been observed immediately after the adrenaline threshold during incremental exercise. Such positive effects could be enhanced by nutritional factors, such as carbohydrate or fluid ingestion, but did not seem to be influenced by the level of fitness. Second, the mediating role of resource allocation has been suggested to explain improvement in cognitive performance during exercise. This effect highlights the importance of motivational factors in such tasks. Finally, when the cognitive performance was performed during exercise, consistent results have indicated that the dual task effect was strongly related to energetic constraints of the task. The greater the energy demand, the more attention is used to control movements.

Arousal↗

Energy substrates, hormone responses and glucocorticoid binding in lymphocytes during intense physical exercise in humans following phosphocreatine administration.

Eight healthy untrained male volunteers pedalled a cycle ergometer according to two exercise protocols: the first involved step-wise increasing physical exercise to maximal (MPE); the second involved prolonged (35 min) submaximal physical exercise (PPE) at 70% of the individual's maximal oxygen uptake. Each volunteer performed these exercise twice, following either an intravenous injection of phosphocreatine (PCr) or a placebo of an isotonic NaCl solution. Anaerobic threshold (AT) was determined from the point of departure of the ventilatory response from linearity and from the sudden increase in venous blood lactate concentrations during MPE. After exercise following placebo administration we observed increases in concentrations of blood substrates, plasma adrenocorticotropin (ACTH), growth hormone and cortisol and in the number of glucocorticoid receptors in lymphocytes without changes in the dissociation constant. Intravenous administration of PCr (starting 1 day before exercise) led to an increase in the total workload (on average by 5.8%) and in AT (on average by 6.8%) during MPE and to a better tolerance of exercise during PPE. Following PCr administration we observed lower blood lactate concentrations and different patterns of some enzyme activities, less pronounced changes in plasma ACTH and cortisol concentrations and in glucocorticoid binding in lymphocytes, but no changes in plasma growth hormone concentrations compared to the placebo. The results showed that intense physical exercise led not only to increases in blood hormone concentrations but also to an increase in the density of glucocorticoid receptors in lymphocytes. Intravenous PCr injection led to smaller changes in ACTH and cortisol concentrations as well as to a lower activation of glucocorticoid binding in lymphocytes.

Adrenocorticotropic Hormone↗

[Development of automated lactate analyzer with continuous blood sampling for monitoring blood lactate and its application for the testing of physical exercise].

The anaerobic threshold is useful for estimating the intensity of physical exercise. It is shown as either an increase in blood concentrations of lactate or a disproportionate increase in ventilation. We developed a lactate analyzer based on an electroenzymatic method with a continuous blood sampling system through a double-lumen catheter. Ascorbic acid, bilirubin, hemoglobin, creatinine, uric acid, and glucose did not interfere the results. The lactate concentrations in blood samples from healthy subjects during physical exercise correlated well (r = 0.993) with results measured by the conventional enzymatic method. We measured the concentrations of blood lactate with a use of this lactate analyzer to see the anaerobic threshold in nine healthy volunteers during exercise on a treadmill with an increasing workload. The point at which lactate concentrations started to increase was detected easily. The anaerobic threshold identified as a disproportionate increase in ventilation was seen at almost the same time. We conclude that the lactate analyzer, with a continuous blood sampling system, can measure precisely concentrations of lactate in blood and can detect the anaerobic threshold during physical exercise.

Adult↗

Reactions of immune system to physical exercises.

The great attention to reactions of immune system to the physical exercises in sportsmen is linked to the growth of training volumes, to the increase of competition numbers and to the elevation of morbidity. Immune deficiency may be considered as the detonator of pathological processes among which acute respiratory diseases (ARD) are investigated most completely in sports medicine. Other pathologies require long-term observations, but it is not so simple to do due to the frequent renewal of sports groups. Besides ARD, there are reports about the growth of cases of poliomyelitis, endotoxemia, allergic and autoimmune disorders. Immune reactions in sportsmen are developed at the background of fever, impaired balance of ergotrophic hormone activity and in a number of cases under conditions of systemic endotoxemia. We have described the extreme type of immune deficiency in sportsmen, in which we could not determine different isotypes of Ig. The phenomenon of Ig disappearance is reproduced under the experimental conditions that opened the way to study its mechanisms. Physical exercises decrease function of immunocompetent cells, their antiviral resistance, antigen presentation and expression of class II MHC molecules. With the involvement of macrophages hyperproduction of IL-6 is developed in muscle tissues. After physical exercises other cytokines also change the state of immunity. Also, neuropeptides getting in touch the links between endocrine and immune systems may make a contribution to immunosuppression. The immunosuppression may be prevented by use of special carbohydrate diets and by administration of complexed preparations. The prophylaxis is capable to control the morbidity, profoundly to increase the training volumes and to enhance the labor efficiency.

Common Variable Immunodeficiency↗

Is physical exercise beneficial for persons with Parkinson's disease?

OBJECTIVE: To review existing studies evaluating the effectiveness of physical exercise on mortality, strength, balance, mobility, and activities of daily living (ADL) for sufferers of Parkinson's disease (PD). DATA SOURCES: The following databases were searched (1) Cochrane Database of Systematic Reviews, (2) Cumulative Index to Nursing and Allied Health Literature (CINAHL), (3) PubMed and (4) Medline/NARIC (National Rehabilitation Information Center) using combinations of key words Parkinson's disease and physical exercise. Only articles written in English were included. References cited were also examined. STUDY SELECTION: Studies were eligible if (1) only patients with PD were included in the intervention study (there were many studies that evaluated the benefits of exercise after stroke, cardiac arrest, sports injuries, surgery, and arthritis, but only a few for patients with PD), (2) the intervention included some form of physical or therapeutic exercise, (3) the effects of the physical exercise were evaluated, and (4) the studies were published in a refereed journal. Because few studies were found that dealt with PD patients exclusively, all studies that evaluated the effectiveness of physical exercise for only PD patients were included. Seven studies met our criteria and were selected. Three of the selected studies were randomized controlled studies, 1 was an open trial, and the other 3 relied on patients' own assessments. DATA SYNTHESIS: Outcomes in the studies were measured in terms of physical improvements in patients with PD, such as improved axial rotation, functional reach, flexibility, balance, muscle strength, short-step gait, and mobility. All studies reviewed show that exercise improves overall performance in PD patients. Improvements were measured using standardized tests and other measurement scales. CONCLUSIONS: The results of the present research synthesis support the hypothesis that patients with PD improve their physical performance and activities of daily living through exercise. Future studies should include the development of standardized exercise programs specific for problems associated with PD as well as standardized testing methods for measuring improvements in PD patients. There is also a need for longer term studies (over 1 year) to assess if improvements achieved during the intervention stage are retained long term.

Activities of Daily Living↗

The level of physical activity and the growth hormone (GH) response to acute physical exercise.

There is no clear evidence about the influence of programmed physical activity (training) on growth hormone (GH) response to acute physical exercise. The aim of this study was to estimate the relationship between the level of physical activity and the serum growth hormone concentration in response to acute physical exercise. The study was performed on 20, healthy male subjects. Based on the level of their physical activities they were divided in two groups of equal size: group 1, trained, and group 2, untrained subjects. All subjects performed one boot of exercise on cycle ergometer, lasting 30 minutes. Work intensity was approx. 65% of VO2 max, and the rate of cycling was 60/min. Serum GH concentrations were measured by IRMA (immunoradiometric assays) method in blood samples obtained in the period of rest, during exercise and in the recovery period. There were marked differences in the dynamics of changes in the serum GH concentrations during exercise period between the groups of various level of physical activity despite the lack of the significant differences in basal level and maximal level of serum GH concentration at the end of exercise. Untrained subjects showed faster increase in serum GH concentration than trained subjects, but in trained subjects the restoration of the basal values in the recovery period was faster. These results indicate that the level of physical activities in young, healthy male subjects has no influence on GH response to acute physical exercise.

Adaptation, Physiological↗

The role of physical exercise in the occurrence of Parkinson's disease.

A case-control study of Parkinson's disease and physical exercise was conducted in a cohort of 50,002 men who attended Harvard College (Cambridge, Mass) or the University of Pennsylvania (Philadelphia) between 1916 and 1950 and were followed up in adulthood for morbidity and mortality data. Cases of Parkinson's disease were identified from responses to mailed questionnaires and death certificates through 1978. Four controls from the same population were selected for each case. The association between physical activity at the time of college and subsequent risk of Parkinson's disease was evaluated for 137 cases and 548 controls, whereas the data on physical activity in adulthood before the disease occurrence was available only for 94 of these cases. Having belonged to a varsity team or having done regular physical exercise in college was associated with a lower nonsignificant risk of Parkinson's disease. In adulthood, practice of moderate or heavy sports was linked to a reduced risk, although more precise analysis revealed that there was only a modest nonsignificant reduction in risk for subjects who do a moderate amount of physical exercise, but this negative association disappears at higher levels of physical expenditure. These results, which require further confirmation, are compatible with a slight protective effect of physical exercise on the risk of Parkinson's disease, although the lack of association cannot be refuted.

Adolescent↗