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Biomedical subjects

W Hollmann

Publications and source records attributed to W Hollmann.

At least 55 records · Page 3Linked to original sources
PubMed1987

[Exercise hypertension: historical, physiologic and clinical aspects of ergometry].

More than a decade before Riva Rocci in 1896 described the principles of blood pressure measurement as still employed today, in 1881 Zadek reported that there is an increase in blood pressure during physical work. The blood pressure increase during physical exercise as well as its extent as a relatively constant physiological response to a given workload were delineated accurately for the first time, however, in the 1950s. There is no significant difference between the blood pressure increase seen in conditioned athletes and untrained individuals at comparable workloads. In healthy male subjects, a comparison was carried out of the reactions of cardiopulmonary and metabolic parameters during five different modes of exercise. The highest values for oxygen uptake as well as the highest heart rates can be observed during treadmill ergometry; with this method, the largest muscle mass is activated. During both treadmill ergometry as well as during step climbing, the blood pressure can be measured only invasively. As compared with bicycle ergometry in the seated position, the stroke volume increase is only relatively small during supine pedaling. Accordingly, to reproduce situations similar to that of everyday activity exercise testing should be carried out in an upright position. Vascular and cardiac catheterization, however, can be performed more easily in the supine than in the seated position. With these facts in mind, the appropriate methods should be chosen according to the needs of the study and the condition of the patient. During continuously increasing workloads, the systolic pressure increases proportionately. Immediately after termination of exercise, this pressure decreases rapidly over two to three minutes. The diastolic pressure measured noninvasively during seated bicycle ergometry is not particularly accurate and should be interpreted with caution. In general, exercise blood pressure should be determined during a standardized test beginning with a workload of 30 watts for three minutes and subsequent workloads incremented 40 watts for three minutes each. The normal ranges for younger and older patients differ substantially. Additionally, body weight exerts an influence on exercise blood pressure. During exercise, patients with hypertension may show one of three different reactions: the increased pressure can be maintained relative to the normal values during the specified workloads, the blood pressure can show normalization and the systolic blood pressure can remain constant or even decrease at higher workloads.(ABSTRACT TRUNCATED AT 400 WORDS)

Blood Pressure Determination↗
PubMed1986

Delayed effects of prolonged exercise on serum lipoproteins.

The delayed lipoprotein changes after a 3-hour running test were examined in 14 moderately trained young male subjects. Fasting blood samples were obtained one day before, immediately before, and one, two, and four days after the race. Nonfasting samples were collected immediately after, one, and three hours after exercise. Three hours after the race, the ratio of unesterified cholesterol to cholesteryl esters was significantly increased, and one and two days after the race it was significantly decreased compared to the preexercise value. The HDL2/HDL3 ratio, measured by density-gradient ultracentrifugation was one and three hours after the running significantly elevated. However, no redistribution of the HDL2/HDL3 cholesterol ratio determined by a precipitation method with polyanions was found at this time. One day postexercise HDL cholesterol rose significantly above the preexercise value, and this was associated with an elevation of the HDL3 subfraction. On the following day a significant increase of HDL2 cholesterol and the HDL2/HDL3 cholesterol ratio was found. The apolipoproteins A-I, A-II, and B, measured by radial immunodiffusion, did not change during the first hours and the first two days after the race. On the second postexercise day the Lp(a) lipoprotein rose significantly above the preexercise value. Compared with the preexercise level the LCAT activity was significantly elevated three hours after the race and significantly decreased two days later. The present study suggests that during the first few days after prolonged exercise a number of plasma lipoprotein changes take place that are similar to those observed after a period of physical training.

Adult↗
PubMed1986

[Physical performance in pregnancy].

To evaluate their physical efficiency, 14 healthy untrained women were examined during pregnancy weeks 16-20, 25-29 and 34-38 and 5 to 10 weeks post partum, by spiroergometry at various exercise levels on the bicycle ergometer. Besides the spiroergometric values, circulatory parameters were measured and serum analyses were carried out. The physical efficiency of the subjects was by no means reduced in the stages of pregnancy investigated. Indeed, several factors indicated an improvement of performance. Thus common features were found regarding the physiological effects of pregnancy and endurance training: increase of the maximum oxygen uptake, lower lactate production when the aerobic/anaerobic threshold was exceeded at high exercise intensity, as well as a relatively lower pulse under exercise. The increased metabolic fat utilisation for energy production in physical work is likewise similar to the effect of endurance training. Many pregnant women occasionally feel that they have reduced physical efficiency. Pregnant subjects were subjected to a standardised exercise test to appraise these complaints objectively. The study carried out was intended to answer the question as to whether the specific processes of adaptation of the cardiopulmonary system in pregnancy would lead to an impairment of physical efficiency. Furthermore, the question was to be answered as to whether the altered metabolic conditions of pregnant women under exercise will influence energy production from carbohydrate and fat metabolism.

Acid-Base Equilibrium↗
PubMed1986

Cardiovascular effects of extreme physical training.

After a short historical remark the development of athlete's heart in childhood is described. Within 2 years significant differences were observed between endurance-trained (swimming) and untrained girls and boys determined by X-ray and echocardiographical examinations. The limits of the physiological size in relation to body weight were not exceeded within 10 years of longitudinal studies. A second point deals with athlete's heart from physiological and clinical viewpoints. The largest healthy heart ever found in our examinations of athletes had a size of 1,700 ml. Sixteen years after stopping the active career it was reduced to 950 ml without a pathological finding. Questionable and pathological cases are described. A third chapter covers the blood supply of internal organs during exercise combined with air or oxygen breathing. In this connection liver, kidneys, heart, lungs, and brain have been investigated. The reduced blood supply of the liver and kidneys during intense exercise on the cycle ergometer was not influenced significantly by inspiration of oxygen. A significant blood volume increase of the lungs was noticed during incremental rates of work. Exercise augmented also blood flow of the brain in relation to the work rate (at 100 W a 27% increase in grey matter flow of the right hemisphere). A fourth chapter deals with new hormonal and neurohormonal aspects related to the cardiovascular system. Beta-endorphines remained unchanged at work rates below the anaerobic threshold but increased significantly during maximal rate of work. The opiate antagonist naloxone abolished the rise in body temperature seen during ergometer exercise. The serotonin antagonist ketanserin lowered the blood pressure and the arterial lactic acid level during an incremental exercise test, similar to the results with the dopamine agonist pergolide. The hormone cardiodilatin is produced in the atrial appendages, and it is a potent substance in the regulation of the cardiovascular system. The adaptive reaction of the sympathetic nerve fibres in the myocard revealed different directions: activation, degeneration, and regeneration. These findings correlated highly significantly with the total amount of catecholamines in the heart muscle.

Adult↗
PubMed1985

Assessment of circulating immune complexes by a solid-phase C1q-binding assay during the first hours and days after prolonged exercise.

A sensitive and specific solid-phase C1q-binding assay using porcine C1q and microtitre plates as a solid phase, served to assess the immune complexes in serum during the first hours and days after a 3-h running test. Fourteen moderately trained male subjects participated in the race and covered 36.3 +/- 3.7 (mean +/- SD) km in 3 h. Blood samples were drawn 1 day before, immediately before, immediately after, 1 and 3 h after and 1, 2 and 4 days after the race. When corrected for the changes of serum total protein, the apparent immune complex concentrations were 1 and 3 h after the race significantly higher (p less than 0.001 and p less than 0.05 respectively) than the pre-exercise values. Two days after the race the values were significantly lower (p less than 0.05) than before the race. These findings provide evidence for the formation of immune complexes after severe physical exercise.

Adult↗
PubMed1985

Relationship between swimming velocity and lactic concentration during continuous and intermittent training exercises.

The present study examined the relationship between lactic acid concentration in capillary blood and swimming velocity during 11 typical endurance exercises (continuous swimming for 30 and 60 min, interval swimming with distances between 50 and 400 m, and with rest periods of 10 and 30 s) and during the "two-speed test" recently described by Mader. It was expected that a better understanding of these relationships could provide evidence how to adjust training intensities from results obtained during the two-speed test. Fifty-nine male swimmers of the German national level participated in this study. After a 30-min maximal swimming test, a mean lactic acid concentration of 4.01 +/- 0.75 mmol/l was found. The corresponding mean velocity was similar to the speed (V4) calculated for the 4 mmol/l level on the basis of the results obtained during the two-speed test (2 X 400). During 30 min continuous swimming at 95% to 105% of the velocity V4, there was a significant correlation (r = 0.82, P less than 0.001) between the swimming speed and the lactic acid concentration. In the 30-min maximal test, the velocity V4 correlated significantly with both the lactic acid concentration (r = -0.58, P less than 0.005) and the swimming speed (r = 0.97, P less than 0.001). During the interval exercises with rest periods of 10 s, the swimming velocities corresponding to the same lactic acid level as during continuous swimming, increased for the 50, 100, 200, and 400 m by 11.23%, 4.21%, 2.95%, and 2.02% of V4, respectively. With rest periods of 30 s, the swimming velocity for the 100, 200, and 400 m increased by 7.34%, 4.22%, and 3.01% of V4, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1985

Historical remarks on the development of the aerobic-anaerobic threshold up to 1966.

During the years 1957 to 1963, we introduced the concept of the onset of anaerobic metabolism to measure cardiopulmonary and peripheral aerobic performance capacity. On the basis of bicycle and crank ergometer work with load increments of 3 min duration, we described a point at which the pulmonary ventilation (VE) increases at a greater rate than O2 uptake (VO2). Because the changes of the arterial blood lactate (Laa) and VE coincide we defined this point as the "point of the optimal ventilatory efficiency," identical with the "O2 endurance performance limit," later called "anaerobic threshold" by Wasserman et al.

Adenosine Triphosphate↗
PubMed1985

Exercise-induced prolactin release is related to anaerobiosis.

The response of plasma PRL to exercise, as performed on a bicycle ergometer under conditions below and above the anaerobic threshold, was studied in 10 normal young men. One hour of submaximal work against a workload at which blood lactic acid remained below 4 mmol/liter (anaerobic threshold) was accompanied by a slight decrease in plasma PRL levels, similar to the changes occurring under control conditions in the same subjects. However, during graded maximal ergometric exercise until exhaustion, plasma PRL rose promptly and significantly (P less than 0.05) when the anaerobic threshold was reached. These data suggest that PRL levels increase provided that the intensity of exercise is such that the anaerobic threshold is reached.

Adult↗
PubMed1985

[Preventive cardiology: lack of exercise and physical training from the epidemiologic and experimental viewpoints].

A survey is given on epidemiological and experimental results of lack of exercise as a risk factor for coronary heart disease. The consequences of endurance training are described. It is evident that endurance sport or training during leisure time can have a greater effect than heavy muscular professional work. The selectively analysed factor "lack of exercise" may be less important as a risk factor than the protective influence of endurance training. Directions are given for carrying out a preventive program of training, with contraindications included.

Adrenergic beta-Antagonists↗
PubMed1985

[Exercise, training and sports in children with asthma from the sports medicine viewpoint].

Asthmatic children can tolerate physical exertion relatively well. They should undergo physical training for social, psychological, educational, and medical reasons. It is important to understand the different effects of different kinds of sport on coordination, flexibility, speed and endurance. Details are described. Swimming is especially recommended for children with an exercise-induced asthma. A high air temperature is favorable. An interval-training is more suitable than a continuous work such as jogging. Postexercise bronchial obstruction can be prevented by prophylactic medication with selective beta-2-sympathomimetica or cromolyn sodium. Details of an endurance-training are described.

Adolescent↗
PubMed1985

[Significance of sports for the heart of the elderly].

The changes in performance of cardiopulmonary metabolic parameters during aging are discussed. With advancing age, maximal oxygen uptake, the aerobic-anaerobic threshold, maximal attainable pulse rate, maximal stroke volume, and maximal peak flow all decrease. The causes are a reduction in the windkessel function of the aorta, loss of elasticity in the arteries, and silting of the peripheral capillaries, as well as other unidentified factors. The lower the aerobic-anaerobic threshold, the greater the reduction in blood flow through the liver and kidneys at given levels of load. This applies particularly to older individuals. The pulmonary circulation increases in inverse proportion to the maximal oxygen uptake value at submaximal load. Cerebral blood flow increases highly significantly in all parts of the left hemisphere at a measured work load of only 25 W, and the further increase at 100 W is again significant. The increase is greater in the gray matter than in the white matter. The maximal minute volume under load runs parallel to the maximal oxygen uptake curve with increasing age. Simultaneously, maximal diffusion capacity decreases and there is a reduction in the quality of distribution and perfusion. The result is an age-related decline of partial oxygen pressure in arterial blood. With advancing age there is an earlier rise in blood catecholamine levels, whereas the density of adrenoreceptors apparently changes only slightly, although their sensitivity decreases. Essentially, 55- to 70-year-old subjects who have gone for decades with no training are as trainable as untrained subjects in the third decade of life. This is true for all the parameter mentioned above. In contrast to younger subjects, muscle biopsies show an increase in activity not only of oxidative enzymes, but also of anaerobic enzymes (e.g., LDH). There is no increase in heart size after 8-12 weeks training. At rest and at given loads, there is an increase in stroke volume accompanied by a reduction in heart rate; peripheral resistance also decreases significantly. The heart of an older person participating in active sport could be placed at risk by inadequate training, but possibly also by excessive demands on intensity and duration.

Aged↗
PubMed1984

Can physical exercise induce an effective fibrinolysis?

The study examined serum fibrin(ogen) degradation products (FDP/fdp) after short and prolonged exercise, before and after training, in young and elderly subjects. Six of 15 well-trained soccer players demonstrated an increase of FDP/fdp after a short graded maximal treadmill test. In 12 elderly subjects short maximal exercise produced no increase of FDP/fdp. However, in most of these subjects an exhaustive work load was not reached. Three of 16 moderately trained young subjects exhibited a small FDP/fdp increase after 45 minutes of submaximal exercise and in 3 of 10 participants an elevation of FDP/fdp was found after a 3 h-running test. Immediately after the race there was a significant (p less than 0.001) increase of fragment D, measured by an enzyme immunoassay. During a second 3 h-race after an 8 week physical training program, the post-exercise FDP/fdp and fragment D increase was slightly enhanced. Plasma fibrinogen was significantly (p less than 0.05) elevated on the fourth day after the 3 h-race before but not after the training program. In conclusion intense and/or prolonged physical exercise caused only a modest increase of FDP/fdp. Physical training seems only minimally to affect this response. It is speculated that in the trained subject, daily exercise-induced fibrinolytic activation might be more relevant to the risk of thrombotic or atherosclerotic disease than a higher absolute resting or post-exercise fibrinolytic level compared with the untrained.

Acute-Phase Proteins↗