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PubMed2005

Comparative analysis of the effects of physical exercise.

The purpose of this study was to assess anthropometrical, somatomotor, and cardio respiratory characteristics of athletes and non-athletes subjects to establish which effects of the organized physical training discriminate well between them. Subjects were 61 athlete and non-athlete medical students. Four groups were formed relying upon gender and physical activity. Body measures were computed. The motor abilities were tested by a set of static and dynamic motor tests, and cardio respiratory functions were recorded. No statistically significant differences were obtained from the comparisons of the body measures of basketball players and non-athlete medical students, except the body height. In contrast, significant differences were found both between the motor performances and between the cardio respiratory functions of the athlete and non-athlete groups. The body mass index (BMI) and the body fat (%) correlated negatively with static hanging, vertical jumping, and balance capability. On the contrary, BMI and body fat correlated positively with systolic blood pressure and vital capacity. The present results show that the effects of regular physical exercise on motor performances and cardio respiratory functions differentiate better between the athlete and non-athlete subjects than the changes in body measures.

Adipose Tissue↗

PubMed1995

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 digitized 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.

Animals↗

PubMed1985

Co-release of neuropeptide Y and catecholamines during physical exercise in man.

Venous plasma levels of neuropeptide Y-like immunoreactivity (with chromatographic properties of synthetic neuropeptide Y) increased in parallel with catecholamines, heart rate and blood pressure during graded physical exercise in man. The plasma levels of neuropeptide Y correlated better with the levels of noradrenaline than adrenaline, suggesting release of a neural origin. Taken together with previous results, this suggests that neuropeptide Y is released together with noradrenaline upon sympathetic activation during physiological conditions in man. Determinations of plasma neuropeptide Y may therefore be valuable in the assessment of sympathetic nerve activity.

Adult↗

PubMed1990

Human neutrophil hydrogen peroxide generation following physical exercise.

The effects of prolonged, submaximal exercise by seven healthy, untrained individuals on the generation of H2O2 by neutrophils was studied. Hydrogen peroxide generation by neutrophils isolated from pre-exercise (control) and post-exercise blood samples was measured 10, 15 and 20 minutes following stimulation with phorbol myristate acetate (PMA). Exercise was associated with a significant elevation in the number of circulating neutrophils and a diminished capacity for neutrophil H2O2 generation following PMA stimulation. Addition of post-exercise plasma to neutrophils isolated from pre-exercise blood caused a small reduction in H2O2 generation, suggesting the presence of an inhibitory factor(s) in the plasma during physical exercise. These results support the concept that exercise may contribute to an attenuation of oxygen-dependent neutrophil killing.

Acute-Phase Reaction↗

PubMed1987

[System analysis of the process of oxygen supply in young sportsmen during physical exercise of various intensities].

Young sportsmen were found to have nonhomogeneous and qualitatively different participation of the hemodynamic, respiratory and tissue mechanisms in formation of the oxygen supply system on discretely increasing physical exercises. In maximal exercises, the O2 utilization in tissues is the main limiting section on oxygen consumption. Mathematic formulae are suggested to estimate the volume of blood circulation per minute according to the magnitude of oxygen consumption and respiratory capacity per minute.

Adolescent↗

PubMed1987

The effects of smoking and physical exercise on temporary threshold shifts.

The Temporary Threshold Shifts (TTS) of 9 habitual smokers and 9 non-smokers were determined twice (via Békésy sweep procedures) after each of three conditions: 10 min of physical exercise, 10 min of 105 dB SPL exposure to a third octave band noise centered around 2 kHz, and 10 min of both exercise and noise. Smokers evidenced less TTS than did non-smokers, particularly when exposed to both noise and exercise and especially in the range of 2.5 to 5 kHz. Heart rate and systolic blood pressure increased more for smokers than for non-smokers, particularly when they were required to exercise. Oral temperature was positively correlated with the magnitude of TTS.

Adolescent↗

PubMed1997

Physical exercise habit: on the conceptualization and formation of habitual health behaviours.

An observation one can make when reviewing the literature on physical activity is that health-enhancing exercise habits tend to wear off as soon as individuals enter adolescence. Therefore, exercise habits should be promoted and preserved early in life. This article focuses on the formation of physical exercise habits. First, the literature on motivational determinants of habitual exercise and related behaviours is discussed, and the concept of habit is further explored. Based on this literature, a theoretical model of exercise habit formation is proposed. More specifically, expanding on the idea that habits are the result of automated cognitive processes, it is argued that physical exercise habits are capable of being automatically activated by the situational features that normally precede these behaviours. These habits may enhance health as a result of consistent performance over a long period of time. Subsequently, obstacles to the formation of exercise habits are discussed and interventions that may anticipate these obstacles are presented. Finally, implications for theory and practice are briefly discussed.

Adolescent↗

PubMed1991

Effect of physical exercise on in vitro production of interleukin 1, interleukin 6, tumour necrosis factor-alpha, interleukin 2 and interferon-gamma.

The present study was designed to examine the effect of physical exercise on production of interleukin-1 (IL-1), interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2) and interferon-gamma (IFN-gamma). Ten young, healthy volunteers underwent 60-min bicycle exercise at 75% of maximal oxygen uptake (VO2max). Blood samples were collected before and during the last minutes of exercise, as well as 2 h and 24 h later. Blood mononuclear cells (BMNC) were stimulated in vitro with either bacterial lipopolysaccharide or phytohaemagglutinin, and the supernatants were tested for the above-mentioned cytokines using bioassays as well as ELISA techniques. The production of IL-6 increased significantly 2 h after exercise, furthermore the production of IL-1 alpha and IL-1 beta was enhanced, although only borderline significant. TNF-alpha, IL-2 and IFN-gamma did not fluctuate in relation to exercise. The increased amounts of IL-1 and IL-6 in the supernatants generated from a fixed number of BMNC are most likely explained by the increased percentage and absolute number of blood monocytes 2 h after exercise. IL-2 and IFN-gamma are mainly produced by CD4+ and CD16+ cells. During exercise the CD4+ subset decreases, while the CD16+ subset increases. The finding of unchanged production of IL-2 and IFN-gamma was therefore expected.

Adult↗

PubMed1987

[Dosed physical exercise in the early detection of cor pulmonale in chronic bronchitis patients].

A combined study of some indices of external respiratory function (vital capacity, air flow peak rate and derivative values), physical exercise tolerance, ECG signs of hypertrophy of the right ventricle and pulmonary hypertension, microcirculation of the bulbar conjunctiva was performed in 125 patients with chronic bronchitis prior to and after submaximum bicycle ergometric testing. All indices in nonobstructive chronic bronchitis slightly changed as compared to controls. Most of the patients with bronchial obstruction at the peak of exercise demonstrated distinct signs of respiratory insufficiency, an increase in bronchial obstruction, pulmonary hypertension and right ventricular hypertrophy. A conclusion was made of the necessity of a wide use of bicycle ergometry in early diagnosis of cor pulmonale. In genesis of the latter the leading role was played by bronchial permeability disorder.

Adolescent↗

PubMed2006

Physical exercise and diabetes during childhood.

Active life and physical fitness may represent the most effective strategies to prevent chronic diseases and to improve growth and development for children, including those with diabetes. Observational studies have demonstrated the association between life style and prevention of chronic diseases in the general population. These studies have been showed a reduction of morbidity for vascular diseases in trained subjects who present adequate cardiovascular fitness and practise regular exercise. The exercise-related protective effects may be mediated in part through components of the metabolic syndrome: improved insulin sensitivity, decreased weight and visceral fat accumulation, reduced low density lipoprotein (LDL) and triglycerides, increased high density lipoprotein (HDL), decreased blood pressure. These effects are more significant in patients with type 1 diabetes (T1DM), because hyperglycemia-related morbidity and mortality are associated with chronic complications. In particular, improved insulin sensitivity may determine a better glucose profile which in turn may positively influence the diabetes-related microvascular complications. Furthermore, improved blood pressure and normalization of lipid profile may also contribute to the prevention of vascular complications. Nonetheless, physical activity can improve psychological well-being by increasing self-esteem and enhancing quality of life. Although patients with T1DM may participate in all kind of sports and physical activities, there are several potential adverse events, including hypoglycemic and hyperglycemic episodes, that can occur. Thus, patients and health professionals have to know in details the physiological effect of physical exercise and its metabolic events in order sport to be healthy and enjoyable for all children, adolescents and young adults with T1DM.

Adolescent↗

PubMed1998

Physical exercise as a human model of limited inflammatory response.

An inflammatory response represents a fundamental series of humoral and cellular reaction cascades in response to infection, tissue injury, and related insults. An excessive response is commonly seen under the pathological conditions of trauma, sepsis, and burns. It is becoming increasingly evident that most, if not all, of the distinguishing features of a classical inflammatory response are detectable in an exercising individual, namely mobilization and activation of granulocytes, lymphocytes, and monocytes; release of inflammatory factors and soluble mediators; involvement of active phase reactants; and activation of the complement and other reactive humoral cascade systems. While the manifestation of many exercise-induced immune and related changes has been reported and confirmed repeatedly, the underlying mechanisms triggering and modulating the elicited immune responses are, at best, poorly understood. Unlike the exaggerated and sometimes uncontrollable inflammatory response in septic and trauma patients resulting in morbidity and mortality, strenuous and severe exercise normally elicits an inflammatory response of a subclinical nature to facilitate the repairing process for site-specific tissue damage. Regardless of the inciting event, for example trauma, infection, or exercise, and given an appropriate triggering signal, a remarkably similar sequence of inflammatory reactions can be reproduced in the affected host. Therefore, physical exercise and training represent an acceptable and good model for the study of limited inflammatory responses in humans.

Cytokines↗

PubMed1989

PHysical exercise: evidence for differential consequences of tryptophan on 5-HT synthesis and metabolism in central serotonergic cell bodies and terminals.

The aim of the present study was to investigate the effects of physical exercise (running) on serotonin (5-hydroxytryptamine, 5-HT) synthesis and metabolism in midbrain on the one hand, and in striatum and hippocampus on the other hand. To address such a question, tryptophan (TRP) and 5-hydroxytryptophan (5-HTP) were measured in running rats pretreated with an inhibitor of aromatic amino acid decarboxylase, namely NSD 1015. In another series of experiments, the consequences of a TRP load on TRP, 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) levels were compared in resting and running rats. Although running triggered a 30% increase in TRP levels in the three brain regions examined, inhibition of 5-HT synthesis by NSD 1015 was found to promote increased (midbrain), unchanged (striatum) or decreased (hippocampus) 5-HTP accumulation in the running situation, respectively compared to that measured in the resting situation. Inasmuch as running-induced elevation in TRP was not associated with an increased 5-HTP accumulation in the striatum and the hippocampus, the consequences of running on regional TRP, 5-HT and 5-HIAA levels were analyzed in saline- and TRP-injected rats. Indeed, running, per se, was found to increase central TRP, 5-HT and 5-HIAA levels. On the other hand, a TRP load that promoted identical increases in central TRP levels in running and resting rats revealed that running, according to the region examined, differentially affected TRP utilization in the 5-HT synthesis pathway. Thus, in the midbrains of the resting and running rats, respective 210-250% increases in TRP led to identical 25% increases in 5-HT and 90% increases in 5-HIAA levels. Conversely, in hippocampus, TRP loads triggered marked increases in TRP levels that were similar in the controls and the runners, but the rise in 5-HIAA promoted by such a precursor load was found to be significantly minored in the runners, compared to the resting rats. Moreover, such a running-induced impairment in 5-HT synthesis and metabolism was even more observable in the striatum; thus, TRP loads which promoted identical increases in striatal TRP levels in the resting and the running rats respectively triggered a 50% and a 32% increase in 5-HT levels and a 76% and a 47% increase in 5-HIAA levels. The results presented herein indicate that under certain pharmacological conditions, TRP utilization into the 5-HT synthesis pathway is altered in serotonergic nerve terminals, but not in the cell bodies of the running rat.

Animals↗

PubMed1992

Spontaneous superoxide generation by polymorphonuclear leukocytes isolated from patients with stable angina after physical exercise.

The activation of circulating polymorphonuclear leukocytes was determined in terms of O2.- generation and elastase release in patients with stable angina (n = 12) and in control subjects (n = 8) after maximal physical exercise and after a 15-min recovery. There was no spontaneous O2.- formation under basal conditions in both groups of patients. On the contrary, there was significant formation of O2.- (p < 0.001) from patients with stable angina measured directly after exercise, along with a slight spontaneous O2.- formation in control subjects (p < 0.05). After recovery, the spontaneous polymorphonuclear leukocyte-O2.- formation decreased but was still present in the patients with stable angina, while in the healthy subjects these values returned to resting levels. The activation of polymorphonuclear leukocytes with phorbol 12-myristate 13-acetate enhanced O2.- formation both in healthy subjects and in patients with stable angina, with a lesser effect in the latter. Moreover, no differences were observed in polymorphonuclear leukocyte-stimulated O2.- formation during the protocol, both in the angina stable patients and healthy subjects. No changes were found in plasma elastase levels among stable angina patients nor in control subjects as a consequence of exercise or recovery. This study indicates there is an early activation of circulating polymorphonuclear leukocytes in terms of O2.- production in stable angina patients during maximal exercise, which is still present after a 15-min recovery. Such activation occurs without elastase release. However, in healthy subjects maximal exercise resulted in very little increase in neutrophil activation.

Angina Pectoris↗

PubMedDate not supplied

Ability to perform prolonged physical exercise in dogs after chronic treatment with thyroxine.

Treatment of dogs with L-thyroxine (T4) for 7 or 21 days had no influence on their body temperature, blood LA and NA concentrations and muscle glycogen content at rest. Only blood FFA and glucose concentrations were significantly higher than those before T4 administration. During exercise performed by T4-treated dogs considerably higher increases in rectal temperature as well as in blood FFA and LA concentrations were found in comparison with control runs. Plasma NA level at the end of exercise was significantly lower in T4-injected dogs than in controls, and blood glucose and muscle glycogen content were similarly decreased in spite of much shorter time of exercise until exhaustion in T4-treated dogs. As a result of the described metabolic and temperature alterations ability of T4-treated dogs to perform prolonged physical exercise was markedly reduced.

Animals↗

PubMed1990

Beta 2-adrenoceptor up-regulation in relation to cAMP production in human lymphocytes after physical exercise.

The effect of isotonic bicycle exercise on beta 2-adrenoceptors and cAMP production in lymphocytes was studied. The origin of the newly exposed receptors was studied by measuring radioligand binding in the presence of hydrophylic or lipophylic 'cold' ligands. During exercise beta 2-adrenoceptor density increased from 1207 +/- 144 to 1776 +/- 152 sites/cell (56 +/- 14%). Isoprenaline induced an increase in cAMP synthesis, which was 68 +/- 15% higher than those values measured before the test. Forskolin did not induce a higher increase in cAMP production after exercise. The increase in receptor density seems not to be due to a transfer of internalized receptors to the membrane surface. We conclude that physical exercise induces an up-regulation of beta 2-adrenoceptors on lymphocytes and that these adrenoceptors are functional.

Adult↗

PubMed2000

Inverse relationship between protein intake and plasma free amino acids in healthy men at physical exercise.

The effect of a "normal" (n = 8) and "high" (n = 6) protein intake (1 and 2.5 g x kg(-1) x day(-1), respectively) and of exercise on plasma amino acid (AA) concentrations, insulin, and glucagon concentrations was followed throughout a continuous 24-h period in adult male subjects at energy balance after six days on a standardized diet and exercise program. Subjects were fasting from 2100 on day 6 to 1200 on day 7 and then fed 10 identical meals hourly until 2100. Physical exercise was performed (46% maximal oxygen uptake) between 0830 and 1000 (fasting) and in a fed state (1600-1730) on each day. The normal-protein group showed fasting plasma AA concentrations that were higher (P < 0.05) than those for the high-protein group, except for leucine, methionine, and tyrosine. Glutamine, glycine, alanine, taurine, and threonine concentrations were distinctly higher ( approximately 30% or greater) throughout the 24-h period in subjects consuming the normal- vs. the high-protein diets. Exercise appeared to increase, although not profoundly, the plasma concentrations of amino acids except for glutamate, histidine, ornithine, and tryptophan. The profound diet-related differences in plasma AA concentrations are only partially explained by differences in the renal clearance of the amino acids. We speculate on the possible metabolic basis for these findings.

Adult↗

PubMedDate not supplied

The effect of short-lasting intensive physical exercise on ATP content in the rat muscles and liver.

Using the method of column chromatography the content of adenyl nucleoptides in the muscle and liver homogentates was determined in the rats subjected to short-lasting, intensive physical exercise. Following the exercise a slight increase in AMP and a decrease in ATP levels were found in the liver. In the muscles the levels of AMP and ADP increased while the level of ATP decreased markedly.

Adenosine Diphosphate↗

PubMed2000

Beta-endorphin (1-31) in the plasma of male volunteers undergoing physical exercise.

beta-Endorphin is an opioid peptide representing the C-terminal 31 amino acid residue fragment of proopiomelanocortin (POMC). The release of beta-endorphin from the pituitary into the cardiovascular compartment under physical or emotional stress has been frequently reported. However, besides beta-endorphin (1-31), nine acetylated or non-acetylated beta-endorphin analogues exist - in addition to N-terminally elongated beta-endorphin derivatives such as beta-lipotropin (beta-LPH). Since conventional radioimmunoassays (RIAs) and even commercially available two site-RIAs pick up at least some of those beta-endorphin derivatives, only "beta-endorphin immunoreactive materials" and not authentic beta-endorphin have been determined in those studies. We have developed a highly specific two site-RIA for beta-endorphin (1-31), which does not cross-react with all beta-endorphin derivatives known to occur as yet. Using this RIA as well as further assays for determination of beta-endorphin (1-31), beta-endorphin immunoreactive material (IRM), ACTH and Cortisol in the plasma of 14 volunteers upon intensive physical exercise, we found authentic beta-endorphin only in about 50% of the plasma samples, representing therein only a minor portion of the beta-endorphin IRM.

Adrenocorticotropic Hormone↗