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At least 865 records · Page 48Linked to original sources
PubMed1980

[Physical exercise in the diabetic. The importance of understanding endocrine and metabolic responses (author's transl)].

During physical activity in normals, metabolic control is well regulated despite major changes in metabolic fuels, glucose and non esterified fatty acids (NEFA). Release of NEFA from adipose tissue is stimulated by a decrease of insulin and blood glucose as well as by an increase of growth hormone, catecholamines and adrenergic stimulation. The increase in glucose utilisation by muscle during physical activity is balanced by an increase in glucose production by the liver. This hepatic glucose production is due to glycogenolysis (beginning of exercise) and by gluconeogenesis (later in time). The metabolic pathways are favoured by decreased insulin and blood glucose levels induced by physical activity and by increased levels of epinephrine, cortisol and glucagon. On the other hand in insulin-dependent diabetics, these compensatory mechanisms might be seriously unbalanced because of non physiologic insulin levels. In well controlled diabetics, moderate physical activity induces the same changes in energetic fuels as in normal controls. When a diabetic exercises after insulin injection, the levels of circulating insulin are always higher than in non-diabetics where blood insulin levels decrease. In diabetics on insulin this supra-normal level of insulin during physical activity decreases hepatic glucose production and increases peripheral glucose uptake with a resultant tendency to hypoglycemia. On the other hand, in poorly controlled diabetics, physical activity can induce a rise in blood glucose. Increased hepatic glucose output, decreased peripheral utilisation of glucose and increased growth hormone, glucagon, epinephrine and cortisol levels might even lead to development of ketosis. Physical activity can disturb the stability of diabetes when insulin levels are either too low or too high leading to high and low blood glucose responses respectively. The benefit of physical activity in the diabetic will therefore depend upon the degree of diabetes control; ideal control is not always easy to obtain or to maintain. Thus, to derive maximum benefit to health both the diabetic and the physician should clearly understand how to adapt treatment to physical activity (prevention of hypoglycemia, change in insulin doses, etc.).

Blood Glucose↗
PubMed1990

Physical exercise and blood flow properties.

In 46 executive level managers at risk for cardiovascular disease, whole blood filterability through five micron pore Nuclepore filters was monitored using a constant flow positive pressure system before and after treadmill exercise and compared to our laboratory standard. Our results show regular exercise compensates not only for the potential damage risk factors represent but also for the physical stress provoked by vigorous exercise.

Blood Circulation↗
PubMed1988

Iron deficiency caused by 7 weeks of intensive physical exercise.

The present study was designed to evaluate the effect of an intensive physical training program involving both isometric and isotonic activities on the body iron status of 8 females and 11 males (age 20 +/- 1 year). The training was carried out over a 7 week period and included 8 h of varying physical activities each day. Venous blood samples were obtained from the subjects prior to the beginning of the training, on day 2 and in weeks 2, 4, 6 and 7 of the program. Blood samples were analyzed for iron, ferritin and hemoglobin (Hb) concentrations, total iron binding capacity (TIBC) and red blood cell count (RBC). Iron levels of males and females decreased 65% after 2 weeks of training (p less than 0.001). At the end of the training program 5 males and 6 females had lower than normal iron values (less than 13.4 mumol.l-1). TIBC increased 25% in women and 18% in men following 2 and 4 weeks of training (p less than 0.001) and remained at this elevated level throughout the training period. Ferritin levels decreased 50% in both sexes after 4 weeks of exercise (p less than 0.05) and remained at this level until the end of the training. Hb and RBC decreased 8-10% in both sexes during the training period. In two of the women anemia occurred after 4 weeks of training. The development of latent iron deficiency in a substantial number of participants after a relatively short period of training is uncommon and may reflect the high intensity of exercise required in this program.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Left ventricular function in physically active and sedentary subjects during physical exercise].

An exercise program based on growing intensity loads (50 watts) was applied to 21 healthy, middle-aged subjects, who were divided into two groups: the physically actives and the sedentaries, according to their physical activity habits. During exercise, which was made on a treadmill, the following variables were measured: oxygen intake (VO2), cardiac frequency (FC), left ventricule ejection time (TEVI), maximal value of the first derivative of ear ensitogram (VMPDDO) and indirect arterial pressure. The active group reached higher values of power and VO2 (absolute and by pulse) and lower values of FC at under maximal works; these data therefore show their best cardiopulmonary capacity. The TEVI in the active group was higher at 150 watts because of the lower FC presented by its assigned subjects. For a maximal exercise condition, both groups had similar ejection times, but the reduction rate of actives' TEVI decreased, which in turn indicates the handling of higher stroke volumes. The VMPDDO relation with the successive increments of work loads was non linear. This index had higher values in the active group, for an exercise strength over 100 watts; this fact allowed the statistical differentiation of both groups. Accordingly, the VMPDDO did indicate the higher left ventricular function of the active subjects during exercise; this findings supports the notion which establishes that resistance training enhances myocardial contraction. In the recovery stage, the sedentaries' VMPDDO increases in a significant way, due to a possible mechanism as to hold stroke volume. In conclusion, the active subjects heart is a more efficient pump than the sedentaries', because of its capacity to handle under maximal exercise higher stroke volumes in the same ejection time, and thus in a higher ejection rate, with equal cardiac frequencies arterial pressures and myocardial oxygen intake.

Adult↗
PubMed1997

Physical exercise induces FGF-2 and its mRNA in the hippocampus.

Clinical and experimental evidence indicate that physical activity has a positive impact on brain function; however, the molecular bases for how exercise affects the structure and function of the brain are largely unknown. We have investigated the influences of variable periods of voluntary wheel-running on the expression of basic fibroblast growth factor and its mRNA in various brain regions. Nuclease protection assays revealed that the hippocampus was the only region examined exhibiting changes in FGF-2 mRNA as a result of exercise. FGF-2 mRNA increased to reach a peak by the 4th night of wheel-running. FGF-2 immunoreactivity, normally located in the perinuclear area of astrocytes, following exercise became stronger and appeared to spread to the cytoplasm and processes of astrocytes. Quantification of the FGF-2-immunoreactive astrocytes showed an increase in density between 2 and 4 nights of running in discrete regions of the hippocampus. These results demonstrate that exercise regulates FGF-2 expression and suggest that growth factors are likely mediators of the positive effects of exercise on the brain.

Animals↗
PubMed1982

Serum FSH, LH, and testosterone in humans after physical exercise.

The serum levels of FSH, LH, and testosterone were determined by radioimmunoassay in 63 men before, during, and after maximal and submaximal physical short- and long-term exercise (800-n running, climbing, 36-k cross-country skiing). In the 800-meter run, significant elevations of FSH, LH, and testosterone were observed, while in all other field and laboratory test (climbing, 36-km cross-country skiing, maximal stepwise bicycle and treadmill ergometry, 90-min submaximal bicycle ergometry) the hormone levels remained unchanged or were decreased. In contrast to FSH and LH, which did not show any clear modification with duration or intensity of exercise or with the state of training, changes of testosterone in the endurance field test (36-km cross-country skiing) seemed to be training dependent. In highly endurance-trained subjects, there was an increase and in less well-trained subjects a decrease of testosterone for equal distances and intensities of exercise.

Adolescent↗
PubMed2001

Physical fitness and self-reported physical exercise among college men and women in 1987 and 1997.

The study examined the relations of self-reported physical activity levels and physical fitness scores for two samples of college students assessed in 1987 (n = 261) and in 1997 (n = 243). Significantly greater exercise was reported by the 1997 women than the 1987 women; amount of exercise reported by men did not differ. For both samples, greater exercise was associated with increased fitness for women and men as assessed by the Hall 1986 Physical Fitness Test Profile, comprised of measures on body fat composition; grip strength; muscle endurance, flexibility, resting heart rate; systolic and diastolic blood pressures; and aerobic power. For the 1987 sample men were more fit than women. For the 1997 sample, women were more fit than men. The 1997 women were more fit than the 1987 women; there was no difference on overall fitness measures of the two samples of men.

Adult↗
PubMedDate not supplied

[The rehabilitative therapy of patients with osteochondrosis of the cervical spine and manifestations of hypermobility bv means of therapeutic physical exercise].

The problems of cervical spine osteochondrosis with hypermobility are of great medical and social significance. Physical rehabilitation methods can improve effectiveness of basic drug therapy. These include isometric exercises, postisometric muscle relaxation, proprioceptive neuromuscular facilitation, postural exercises and special massage.

Acute Disease↗
PubMed1990

Some metabolical aspects of physical exercise under laboratory and field conditions.

Parameters of exercise physiology were studied in nearly 300 subjects to resolve whether these indices were equally suitable under laboratory and field conditions to assess the level of physical fitness and optimum work load. Respiratory gas exchange, heart rate and exercise acidosis parameters were studied. The inference drawn on the basis of the obtained data has been that both the mode and the intensity of the imposed exercise exert significant influence on the variation of physiological parameters. During running either on the treadmill or in the field test, blood lactate levels were comparable, but performances related to these concentrations were not the same. When different modes of exercise were employed, also lactate levels differed between the laboratory and field studies. The performance of patients under or after exercise rehabilitation following acute myocardial infarction by using instrumental monitoring in the laboratory was found to excel that attained during rehabilitation exercise training. Any change in the level of physical fitness can only be reliably followed when physiological parameters are obtained with the same mode of exercise and intensity under the same environmental conditions. Modern training planning of sports and exercise should take into account the data derived from both the laboratory and the field studies concerning cardiorespiratory system and metabolism.

Acidosis↗