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Biomedical subjects

W Kindermann

Publications and source records attributed to W Kindermann.

At least 109 records · Page 6Linked to original sources
PubMed1986

[Ergometry procedures independent of body weight in children with special reference to blood pressure behavior in stress].

UNLABELLED: For the purpose of investigating differences in terms of gender and methodology, a group of 80 healthy children engaged in leisure-time sport activities (male: n = 50; 10.9 +/- 1.1 years; female: n = 30; 11.5 +/- 1.1 years) was divided into 3 groups, which were then subjected to different ergometric procedures. In group I, boys and girls were compared in a bicycle ergometry in an upright seated position. In group II, a bicycle ergometry in upright seated position was compared with a bicycle ergometry in a supine position. In group III, a bicycle ergometry in upright seated position was compared with a treadmill exercise. Bicycle ergometry was started at 25 W; workload was increased in steps of 25 W every 3 min until the children felt exhausted. RESULTS: No differences with respect to gender were found for maximum oxygen uptake, maximum heart rate and maximum lactate. The relevant parameters were also similar on submaximal levels of exercise intensity. All children reached a degree of thorough physical exhaustion at heart rates close to 200 X min-1. As in adults, maximum oxygen uptake decreased in the following order: treadmill exercise greater than bicycle ergometry in upright seated position greater than bicycle in supine position. Systolic and diastolic blood pressure on the various levels of exercise were lower than among adults.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1985

[Apolipoproteins and lipoproteins with differing physical activity and performance capability].

In 216 healthy subjects (74 endurance trained persons, 87 variably trained subjects and 55 sedentary individuals) the behaviour of triglycerides, total cholesterol, lipoproteins and apolipoproteins in blood serum - all in relation to physical performance capacity - were determined in the early morning under fasting conditions. HDL-/total cholesterol (%) as well as the ratios LDL/HDL and Apo A1/Apo A2 proved to have the highest selectivity. Only marginal differences or none at all between the groups were found for Apo B, Apo A2 and total cholesterol. In an analysis of correlation the strongest relation with physical performance was found for HDL-/total cholesterol (%), Apo A1/Apo A2, Apo A1 and LDL/HDL. No significant correlations were found for total-cholesterol, Apo B and Apo A2. When the influence of age and body weight was excluded in an analysis of partial correlation Apo A1 showed the strongest relation to physical performance. The relevant partial correlations for Apo A1/Apo A2, HDL-cholesterol and HDL-/total cholesterol (%) were found to be weaker. With regard to the influence of increased physical activity on the human lipid metabolism it was concluded that the determination of lipoproteins can be significantly supplemented by the determination of apolipoproteins. The behaviour of Apo A1 and Apo A1/Apo A2 indicates that enhanced physical activity increases the vasoprotective HDL2 subfraction.

Adult↗
PubMed1985

[Effect of calcium antagonists on physical fitness and metabolism].

In a cross-over double-blind trial on 15 healthy male volunteers the effect on physical exercise capacity and metabolism of single oral doses of 90 mg diltiazem or 20 mg nifedipine was compared. Both maximal physical exercise capacity and sustained exercise capacity remained unchanged after each calcium antagonist. Heart rate was higher after nifedipine but lower after diltiazem than after placebo, although the differences at the individual exercise steps were small and significant in only some. Plasma noradrenaline levels on submaximal exercise rose significantly higher after nifedipine than after diltiazem or placebo. Somatotropin, cortisol, insulin as well as carbohydrate and fat metabolic substrates were similar after the two calcium antagonists and placebo. It is concluded that short-term administration of diltiazem and nifedipine does not influence physical exercise capacity and metabolism.

Adult↗
PubMed1985

Physical performance and serum potassium under chronic beta-blockade.

Various publications have described a beta 2-receptor regulated potassium transport system in the cellular membrane of human skeletal muscle. To examine the suggestion that serum potassium alterations are among the causes of premature muscular fatigue during physical exercise under pharmacological blockade of beta-receptors, we have compared the influence of sustained blockade with a beta 1-selective blocker and a nonselective beta-blocker on the levels of serum potassium before, during and after a physical exercise test. 63 healthy physical education students received in random order and under double blind conditions either 100 mg Metoprolol (beta 1-selective) or 80 mg Propranolol (non-selective), or placebo daily for 3 months. Serum potassium was measured before, during (at 150 Watt and at the end of exercise) and after a bicycle exercise with a stepwise increase in work loads. After three months of beta-blocker treatment serum potassium levels during exercise were significantly higher than in control subjects receiving the placebo, and it took longer for the serum potassium levels to return to the resting level in the beta-blocker treated subjects. At rest, however, the levels were not found to be statistically different. In the subjects receiving Propranolol the post-exercise serum potassium levels were higher than in the subjects receiving Metoprolol. Three days after cessation of the medication these differences were no longer perceptible. Our findings confirm the existence of a beta-receptor regulated potassium transport system in human skeletal muscle and indicate that the transmembranous potassium transport in human skeletal muscle is predominantly regulated via beta 2-receptors, although beta 1-receptors seem also to be involved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Metabolic and hormonal responses to exhaustive supramaximal running with and without beta-adrenergic blockade.

The metabolic and hormonal responses to exhaustive short-term supramaximal exercise were studied in 10 male physical education students. The exercise task was a single bout of running on the treadmill at 22 km X h-1 and 7.5% slope. It was performed with single oral doses of 100 mg Bupranolol (non-selective beta-blockade), 100 mg Metoprolol (beta-1-selective blockade), and placebo. Arterialized capillary and venous blood were sampled until 30 min post exercise. Time to exhaustion was 52.0 +/- 2.6, 47.6 +/- 2.0, and 46.0 +/- 1.9 s in the control, Metroprolol, and Bupranolol experiments. At cessation of exercise, adrenaline and noradrenaline were grossly elevated in all three conditions. Lactate and glucose increased markedly, this being accompanied by increasing insulin in the control and Metoprolol, but not the Bupranolol trials. Glycerol increased moderately, while FFA were depressed. Growth hormone showed a delayed increase at 15 and 30 min post exercise. Cortisol was unaffected by exercise. beta-blockade reduced the increases of lactate, glucose, glycerol, insulin, and growth hormone, exaggerated the depression of FFA and had no effect on cortisol. The results demonstrate that the strong sympatho-adrenal response to exercise of this nature is a major determinant of the increase of glucose at cessation of exercise. The hyperglycemia in concert with beta-2-adrenergic stimulation leads to elevation of insulin. Furthermore, lipolysis is controlled by beta-adrenergic stimulation. The delayed increase of growth hormone seems to be triggered by the declining glucose level during recovery.

Adrenergic beta-Antagonists↗
PubMed1984

[Behavior of physical endurance and metabolism during acute beta 1 and beta 1/2-blockade].

UNLABELLED: The effect of acute beta 1-blockade (100 mg metoprolol) and beta 1/2-blockade (2 mg levobunolol) on exercise performance and metabolism was studied in 16 healthy male physical education students. The study was carried out in a randomized double blind cross-over fashion. The maximal oxygen uptake was unchanged in all conditions, but maximal exercise capacity was reduced by 4% (beta 1-blockade) and 5% (beta 1/2-blockade). Maximal lactate concentration was reduced by 10% (beta 1-blockade) and 20% (beta 1/2-blockade). In 50 min treadmill exercise with 68% of maximal exercise capacity, beta 1/2-blockade led to premature exhaustion in 50% of subjects. Moreover, blood levels of glucose decreased (in some subjects to about 2.5 mmol X 1(-1], while the values were unchanged under beta 1-blockade. Free fatty acids and glycerol were similarly reduced by both beta-blocking agents. HGH, cortisol, adrenalin, and noradrenalin increased under beta-blockade, but more under beta 1/2-blockade than under beta 1-blockade. Insulin remained unchanged as compared with the unmedicated condition. The perceived exertion was elevated under both beta-blocking agents. CONCLUSION: Beta 1-blockade affects exercise performance, especially endurance performance, less than beta 1/2-blockade due to unaffected beta 2-receptors mediating glycogenolysis in the skeletal muscles.

Adrenergic beta-Antagonists↗
PubMed1983

Assessment of anaerobic capacity in runners.

A new method for assessment of anaerobic capacity is presented. It consists of two treadmill runs at 22 km X h-1 and 7.5% slope, the first one being interrupted after 40 s (submax. test), the second continuing until volitional exhaustion (max. test). Measured variables are the increase in arterial lactate concentration over the pre-exercise value in the submax. test (delta L40), the maximal arterial lactate level in the max. test (Lmax), and time to exhaustion (tmax). Fifty-five male runners of high competitive level were examined with this procedure, including 400-m runners of differing performance capacity (400 m A and B/C), middle-distance (MD), long-distance (LD), and marathon runners (M). Eleven physical education students served as controls (C). tmax was 88.3 +/- 11.0, 85.2 +/- 11.4, 83.1 +/- 12.7, 63.1 +/- 11.4, 43.7 +/- 7.5, and 50.7 +/- 5.0 s for 400 m A, 400 m B/C, MD, LD, M, and C. The corresponding values for Lmax were 17.47 +/- 1.68, 17.52 +/- 2.03, 16.27 +/- 2.18, 13.44 +/- 2.13, 10.13 +/- 2.68, and 15.54 +/- 1.43 mmol X 1(-1) and for delta L40 5.93 +/- 1.10, 7.13 +/- 1.55, 6.39 +/- 0.89, 6.68 +/- 1.18, 8.19 +/- 1.37, and 10.76 +/- 1.62 mmol X 1(-1). The differences in delta L40, most likely reflecting differences in high energy phosphate utilization, suggest that excellent performance in any running event is associated with increased alactacid anaerobic capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Effect of beta-adrenergic blockade on supramaximal exercise capacity.

Fourteen male physical education students performed a single bout of running until exhaustion on the treadmill at 22 km/h and 7.5% slope. They received single oral doses of 100 mg bupranolol (nonselective beta-blockade), 100 mg metoprolol (beta-1-selective blockade), and placebo 60-90 min before running. Arterialized capillary blood was sampled repeatedly until 30 min after exercise for assessment of lactate and glucose. Adrenaline and noradrenaline were determined in venous plasma before and immediately after exercise. Running time until exhaustion was 49.3 +/- 2.3 s in the control experiment, 44.5 +/- 2.0 s with metoprolol, and 42.7 +/- 2.0 s with bupranolol. The reductions under beta-blockade were statistically significant. With both beta-blockers the increases of the lactate and glucose blood levels were significantly reduced, the levels being almost identical with metoprolol and bupranolol. The post-exercise levels of adrenaline and noradrenaline did not differ significantly between the control, metoprolol, and bupranolol experiments. It is concluded that determination of the lactate and glucose levels in blood did not allow assessment of the mechanism by which beta-blockade impairs the capacity for supramaximal exercise. Besides reduced anaerobic energy release due to inhibition of glycogenolysis, other beta-blocker effects are considered.

Adrenergic beta-Antagonists↗
PubMed1983

[The effect of norfenefrine on circulation, plasma catecholamines and metabolism at rest and during exertion].

In a single-blind random cross-over study the influence of a Norfenefrin infusion (2-4 mg/kg per minute) on circulation, carbohydrate and fat metabolism, catecholamines, growth hormone, cortisol, and insulin was investigated. The investigations were carried out on 12 healthy male physical education students at rest and during physical exercise. Under Norfenefrin, heart rate was reduced at rest (-30%) and under low and medium work load (150 watts: -9%); under maximal work load heart rate remained unchanged. Systolic blood pressure at rest increased by 29%; the results under physical exercise differ only slightly, and during increased work load they did not differ significantly. Diastolic blood pressure, in contrast, increased at rest (+23%) and under submaximal (150 watts: +12%) and maximal work load (+12.5%). The product of systolic blood pressure and heart rate was significantly decreased at rest under Norfenefrin, whereas it tended to decrease only slightly during work load. Adrenaline remained unchanged, while noradrenaline had a tendency to decrease only slightly during submaximal work load and was significantly lower during maximal work load. Glucose, lactate, glycerol, free fatty acids, and triglycerides, as well as growth hormone, cortisol, and insulin, remained unchanged. The physical working capacity remained unaffected. These observations confirm the predominant alpha-receptor-stimulating effect of Norfenefrin. The decrease in noradrenaline during exercise indicates the ability of Norfenefrin to interfere with the autoregulation of transmitter release and to replace endogenous noradrenaline.

2-Hydroxyphenethylamine↗
PubMed1982

[Catecholamines, GH, cortisol, glucagon, insulin, and sex hormones in exercise and beta 1-blockade (author's transl)].

The effects of beta-1-adrenergic blockade (100 mg metoprolol) on metabolism in exercise was examined in 14 healthy males who worked for 50 min on a treadmill at 65% of their maximal exercise capacity. The tests were carried out in a double blind fashion. Glucose and lactate were determined in arterialized capillary blood, free fatty acids, glycerol, growth hormone, cortisol, glucagon, insulin, testosterone, and estradiol in serum, and adrenaline and noradrenaline in plasma. Lactate and glucose were not significantly affected by beta-1-adrenergic blockade, free fatty acids and glycerol were reduced by 50% and 30% respectively as compared with the unmedicated condition. Adrenaline and noradrenaline levels were increased by 104% and 54% respectively, growth hormone by 60%, cortisol by 72%, and glucagon by 36% when compared with the control experiments. Insulin and estradiol were unaffected, testosterone was depressed by 21% under medication. The results demonstrate that during prolonged exercise beta-1-adrenergic blockade depresses lipolysis. Energetic deficiency is prevented by counter-regulatory increases of various hormones. Consequently, from the metabolic point of view there is no indication of impairment of prolonged exercise capacity under beta-1-adrenergic blockade.

Adrenergic beta-Antagonists↗
PubMed1982

[Lipoprotein cholesterol in different physical activities. A comparative study in healthy individuals of different ages and patients with coronary heart disease (author's transl)].

The effects of habitual sporting activity on the serum lipoprotein pattern were examined in 415 males with differing physical activity levels, differing fitness conditions, and differing ages. Of these, 260 were competitive athletes in different events between the ages of 17 and 30 years, 37 were amateur sportsmen, and 20 sedentary individuals of the same age served as control. Sixty amateur sportsmen between the ages of 40 to 60 years in different sporting activities were compared with 19 healthy sedentary controls and 19 patients with coronary heart disease of the same age. Independently of age, the physically active tended to have a reduced LDL-cholesterol, the reduction was statistically significant in some events. No relationship was apparent between the type of physical activity and the magnitude of the LDL-cholesterol reduction. In the sportsmen HDL-cholesterol tended to be higher. In the events demanding a high aerobic capacity the elevation was statistically significant. A positive correlation between HDL-cholesterol or HDL-/total cholesterol, respectively, and maximal oxygen uptake was found. In the majority of events the reduction in total serum cholesterol was not statistically significant. The results demonstrate that habitual sporting activity in events with dynamic exercise involving large muscle groups goes along with a lipoprotein pattern, which in epidemiologic studies has been shown to be associated with decreased coronary risk. This effect is independent on age. The necessary amount of training appears to be equivalent to the amount required to produce the cardiovascular adaptations determined to reduce the risk of coronary heart disease.

Adolescent↗
PubMed1982

Effect of maximal oxygen uptake and different forms of physical training on serum lipoproteins.

260 well trained male sportsmen between 17 and 30 years of age participating in a variety of events were examined for total serum cholesterol and lipoprotein cholesterol and compared with 37 moderately active leisure-time sportsmen and 20 sedentary controls of similar ages and sex. Lipoprotein cholesterol distribution was determined by quantitative electrophoresis. Mean HDL-cholesterol increased progressively from the mean of the sedentary control to the mean of the long-distance runners, indicating a graded effect of physical activity on HDL-cholesterol. In all sporting groups mean LDL-cholesterol tended to be lower than in the controls, no association between LDL-cholesterol and form of training being apparent. Except for the long-distance runners, all sporting groups tended to be lower in total cholesterol than the controls. The HDL-/total cholesterol and LDL/HDL ratios yielded a better discrimination between the physically active and inactive than the HDL-cholesterol alone. Significant positive correlations with maximal oxygen uptake and roentgenologically determined heart volume were found for HDL-cholesterol and HDL-/total cholesterol, and negative ones for LDL/HDL. Differences in the regressions among subsets made up of sporting groups under different physical demands suggest a positive relationship between lipoprotein distribution and the magnitude of the trained muscle mass.

Adolescent↗
PubMed1982

Catecholamines, growth hormone, cortisol, insulin, and sex hormones in anaerobic and aerobic exercise.

Seventeen male physical education students performed three types of treadmill exercise: (1) progressive exercise to exhaustion, (2) prolonged exercise of 50 min duration at the anaerobic threshold of 4 mmol . l-1 blood lactate (AE), (3) a single bout of short-term high-intensity exercise at 156% of maximal exercise capacity in the progressive test, leading to exhaustion within 1.5 min (ANE). Immediately before and after ANE and before, during, and after AE adrenaline, noradrenaline, growth hormone, cortisol, insulin, testosterone, and oestradiol were determined in venous blood, and glucose and lactate were determined in arterialized blood from the earlobe. Adrenaline and noradrenaline increased 15 fold during ANE and 3--4 fold and 6--9 fold respectively during AE. The adrenaline/noradrenaline ratio was 1 : 3 during ANE and 1 : 10 during AE. Cortisol increased by 35% in ANE (12% of which appeared in the postexercise period) and 54% in AE. Insulin increased during ANE but decreased during AE. Testosterone and oestradiol increased by 14% and 16% during ANE and by 22% and 28% during AE. The results point to a markedly higher emotional stress and higher sympatho-adrenal activity in anaerobic exercise. Growth hormone and cortisol appear to be the more affected by intense prolonged exercise. Taking plasma volume changes and changes of metabolic clearance rates into consideration, neither of the exercise tests appeared to affect secretion of testosterone and oestradiol.

Adult↗
PubMed1982

Comparison of prolonged exercise tests at the individual anaerobic threshold and the fixed anaerobic threshold of 4 mmol.l(-1) lactate.

Prolonged physical exercise tests (50 min) at the threshold of 4 mmol . l-1 lactate (ATc) and at the individual anaerobic threshold (IAT) were applied in 19 rowing athletes. In each of the rowers (n = 19) work loads corresponding to the IAT did not result in a gradual lactase accumulation or exhaustion within 50 min of exercise. Means of lactate concentration and heart rate at the end of exercise were 4.0 +/- 1.6 mmol . l-1 and 182 +/- 13.0 beats . min-1, respectively. In 15 of 19 rowers, the IAT corresponded to lower work loads than the ATc. In these cases, prolonged exercise tests at the ATc showed gradual increases in lactate concentrations to a mean of 9.6 +/- 1.2 mmol . l-1, associated with exhaustion at a mean working time of 14.4 +/- 6.3 min and a mean heart rate of 192 +/- 10.4 beats . min-1. In four rowers, the IAT was found at identical (n = 3) or higher (n = 1) work loads than the ATc. In these cases, after an initial increase no further rise in lactate concentrations in blood was observed, and exhaustion did not occur during the prolonged exercise tests. These findings support the conclusion derived from the lactate kinetics model that the IAT defines the work load at the maximal lactate steady state.

Adolescent↗