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Biomedical subjects

H Liesen

Publications and source records attributed to H Liesen.

36 records · Page 2Linked to original sources
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

[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

[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↗
PubMed1981

[The behavior of the physical performance capacity and the trainability of the cardio-pulmonary system in elder persons (author's transl)].

It is described the behaviour of the performance capacity of the cardio-pulmonary system during aging. The maximal O2-uptake declines beyond the third decade of life. The average mas has lost 1/3-1/4 of his earlier maximal performance capacity with the 60 year of life, the woman ca. 1/4-1/5. The causes are named. It follows a description of the work reaction of the cardio-pulmonary system during dosed ergometer strain. The influence of an endurance training on the untrained persons of the 7, decade of life is qualitative the same as in the young person. That applies in particularly for the aerobic capacity and the maximal stroke volume. Optimum kinds of sports are endurance sports with a low value of the quotient: (Formula; see text).

Achievement↗
PubMed1977

Modifications of serum glycoproteins the days following a prolonged physical exercise and the influence of physical training.

Eight male subjects (mean age 24.1 +/- 2.6 years) performed at intervals of 2 weeks successively a 3 h and two 2 h runs of different running speed. The days following the running there were moderate elevations of C-reactive protein, haptoglobin, alpha-1-acid glycoprotein, coeruloplasmin, transferrin, alpha-1-antitrypsin and plasminogen. There were small or no changes of albumin, alpha-2-macroglobulin and hemopexin. The elevations of the "acute phase reactants" were examined in three male subjects following a 2 h run before and after an endurance training period of 9 weeks. This demonstrated a decreased acute phase response after training as illustrated by the changes of C-reactive protein, haptoglobin and alpha-1-acid glycoprotein in spite of higher posttraining running speeds. Well-trained athletes have elevated levels of the serum protease inhibitors alpha-1-antitrypsin, alpha-2-macroglobulin and C1-inhibitor. These antiproteolytic glycoproteins might limit exercise-induced inflammatory reactions.

Adult↗
PubMed1977

Effects of 8 weeks' endurance training on skeletal muscle metabolism in 56-70-year-old sedentary men.

The effects of 8 weeks' endurance training on muscle metabolism at rest and after a submaximal bicycle ergometer exercise were studied in 31 previously sedentary men, aged 56-70. Training consisted of 3-5 one hour exercise bouts per week including walking-jogging, swimming, gymnastics and ball games. The effects of training were similar to those previously reported for younger men. Mean maximal oxygen uptake increased (11%), as did the resting values for muscle glycogen concentration, the enzymes representing aerobic energy metabolism (malate dehydrogenase, succinate dehydrogenase), and also some of the anaerobic enzymes (creatine phosphokinase, lactate dehydrogenase). Lactate production during submaximal work decreased. The enzyme activities were lower following acute exercise both before and after training.

Aged↗