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Biomedical subjects

S Sprynarová

Publications and source records attributed to S Sprynarová.

At least 19 recordsLinked to original sources
PubMed1989

Ventilatory threshold and mechanical efficiency in endurance runners.

In order to evaluate changes in parameters at the ventilatory threshold (VT) and in mechanical efficiency (ME) during training in the years 1982 and 1983 we tested seven top-class endurance runners on a treadmill. The VT and ME were assessed during their training period (January 1982 and 1983) and during their competitive period (March and July 1982). The maximal functional variables were almost constant during the training year, the maximal change in VO2max being about 5%. Similarly, VO2 at the VT was almost constant; the maximal change in VO2 at VT was also about 5%. Substantially greater changes, about 10%, were recorded in the velocity of running at the VT, at which the maximum was attained in July (18.9 +/- 0.8 km.h-1 or 5.25 +/- 0.22 m.s-1); this value was significantly higher than values assessed during the remaining tests. The greatest change, about 23%, during the training year was found in ME, for which the maximum was attained in July (35.7% +/- 2.1%). This was not significantly different from the value recorded in March (34.5% +/- 3.3%), but both values were significantly higher than those recorded during the training period. We can therefore conclude that in highly trained endurance runners the times needed to attain the optimal conditions for sports performance differ from the point of view of special speed training and from the point of view of mechanical-metabolic readiness.

Adult↗
PubMed1987

The influence of training on physical and functional growth before, during and after puberty.

In boys, the ages at which growth rates for body weight, height, VO2max, maximum O2 pulse and VImax reached their peaks were approximately the same (means and SD: 14.64 +/- 0.98, 14.67 +/- 0.99, 14.71 +/- 1.59, 14.38 +/- 1.36 and 14.64 +/- 1.42 years respectively). There was a positive relationship between the peak velocities of functional capacity indicators (VO2max 0.79 +/- 0.19 1.min-1.year-1, O2 pulse max 4.1 +/- 1.20 ml.year-1, VImax 27.3 +/- 7.15 l.min-1.year-1) and the peak growth velocity of weight and/or height (weight 9.1 +/- 1.92 kg.year-1, height 9.8 +/- 1.92 cm.year-1). A positive relationship between the age at peak velocity of VO2max and O2 pulse max with the age at peak velocity for body weight was also found (r = 0.524 and 0.400 respectively). No relationship was revealed between the age at peak velocity on the one hand and the peak velocities of body weight, height, VO2max, O2 pulse or VImax on the other. Moderate training did not influence acceleration in growth--the age at peak velocity and the peaks of the growth rate did not differ in groups with a different regime of exercise (higher - n = 8, medium - n = 9, lower - n = 12; the peak velocity of VO2max--means and SD--being 0.85 +/- 0.15, 0.76 +/- 0.22 and 0.78 +/- 0.17.min-1.year-1 respectively).

Adolescent↗
PubMed1987

Relationships between body dimensions and resting and working oxygen consumption in boys aged 11 to 18 years.

The relationships between VO2 at rest, VO2max and VO2 during submaximal work on a treadmill with body weight, height and lean body mass assessed by densitometry were analyzed annually in 39 boys aged 11 to 18 years. Interindividual differences in VO2 at rest and VO2max during growth depended in the first place on interindividual differences in lean body mass, to a lesser extent on differences in body weight and least on differences in height. Intersubject differences in VO2 during submaximal work were primarily conditioned by differences in body weight, due to the fact that, at a given running speed, energy output depends on body weight. The differences in submaximal VO2 depended to a lesser extent on differences in lean body mass and least on differences in height. The relationships between VO2 increments and increases in body dimensions were somewhat different in 90 boys between the ages of 11 and 15 years: VO2max increments were determined primarily by changes in body weight and height, changes in lean body mass being of secondary importance. Increases in submaximal VO2 were influenced decisively by increments in body weight, followed by increments in lean body mass and least by increments in height. In the equation y = a.xb expressing the relationship of VO2max to body weight and height, the values of b at the ages of 14 and 15 years were 0.87 and 0.88 in relation to body weight, 2.63 and 2.72 in relation to height. These values are significantly higher than the theoretical values of 0.67 for body weight and 2.00 for height. Similar significant differences from these theoretical values were found for all values between the ages of 11 and 15 years.

Adipose Tissue↗
PubMed1987

Ventilatory threshold in various groups of highly trained athletes.

The ventilatory threshold (VT) was determined on a treadmill in highly trained male marathon, male and female long-distance, young male long-distance, adult male and female and young female middle-distance runners, modern pentathlonists, adult canoeists of both sexes, young male canoeists and football players, and on a bicycle ergometer in table tennis players, water slalom paddlers, young female canoeists rowers, and ice hockey players. Young female canoeists were also examined on the paddling ergometer and rowers on the rowing ergometer. VT expressed in %VO2 max was higher the longer the duration of racing performance (in marathoners 86.7%). %VO2 max at the VT level depends on the type of load and is higher the better the organism is adapted to a load. In young female canoeists and rowers examined on the bicycle ergometer, we found the VT level at 74.2% and 74.6% of %VO2 max, respectively. In the case of specific loading, we recorded 84.8% and 85.0% of %VO2 max, respectively, in the same athletes. In the case of nonspecific loading highly trained individuals may have low VT values close to the level characteristic for normal subjects. In relatively equally trained young and adult athletes we did not find significant differences in %VO2 max at the VT level (for long-distance runners, 85.2% and 85.3%, respectively, in female middle-distance runners, 82.8% and 82.7%, respectively, and in canoeists 81.3% and 78.9% of %VO2 max, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Comparison of the anaerobic threshold and mechanical efficiency of running in young and adult athletes.

We determined noninvasively in a laboratory on the treadmill the anaerobic threshold (AT) (ventilatory threshold) and mechanical efficiency (ME) of running in 7 adult male long-distance runners (mean age = 24.1 yrs) and 17 adolescents (17.0 yrs), in 8 adult female middle-distance runners (23.2 yrs), in 12 young (16.1 yrs) and in 28 adult male canoeists (22.8 yrs), and in 10 juniors (17.4 yrs). We did not find significant differences in the metabolic adaptation characterized with the help of % VO2max on the AT level between relatively equally trained juniors and adults. In long-distance runners the % of VO2max on the AT level was 85.3% for adults and 85.2% for adolescents, in female middle-distance runners 82.8% and 82.7%, respectively, in adult canoeists 78.9%, and in juniors 79.8%. In ME which characterizes the degree of adaptation to the running and depends on the years of training and thus on the differences in racing performance, the values were lower for young athletes than for adults. The ME found in long-distance runners was 25.4% for young athletes and 32.4% for adults, in middle-distance runners 28.4% and 30.3%, respectively, and in canoeists 24.5% and 26.7%, respectively. The difference was significant only in long-distance runners where the greatest difference in racing performance (about 15%) is also found. The close similarity in responses to submaximal work intensities in adults and young sportsmen or subjects of equivalent fitness suggests caution in the interpretation of agewise decrements observed in physiologic variables which may be sensitive to physical fitness status.

Adolescent↗
PubMed1983

Effects of exercise on serum cortisol and thyroid hormones.

Serum levels of hydrocortisone, T4, T3 and rT3 were estimated before and after exercise. In group A, untrained young subjects had to cope with a submaximal, fractionated load on a bicycle ergometer. T3 increased, rT3 and cortisol decreased, T4 remained unchanged. Sportsmen in group B accomplished a 10 or 15 km run as a part of their regular training. A rise of cortisol and rT3 was observed, T3 remained unchanged and T4 decreased. In better trained sportsmen the initial level of serum T3 exceeded the upper border of normal values (3.3 nmol/l) and the terminal values of cortisol reached a higher value than in the less trained subjects. It is suggested that the mobilization of fuel from energy stores and the oxidative processes are better regulated in trained sportsmen than in untrained subjects. A sign of the best adjustment to a long run was accompanied by an initial serum T3 above the normal borderline and by a great increase of cortisol after the run.

Adult↗
PubMed1983

Muscle enzyme activities and fibre composition (m. vastus lateralis) and efficiency of the cardiorespiratory system in cross-country skiers.

Fourteen male cross-country skiers (class I and II, average age 20.5 years) were examined by biochemical and histochemical methods. The activity of selected enzymes of energy metabolism and the percentage ratio of different types of muscle fibres (m. vastus lateralis) were assessed. Furthermore, the maximum values of the cardiorespiratory system and post-loading pH and blood lactate were determined after performance on a treadmill. The mitochondrial enzyme activities were relatively high with a considerable scatter in the values of HOADH activity. The glycolytic enzyme activities were on the same level as in subjects not engaged in sports. The percentage composition of muscle fibres was as follows: FG - 7.56 %, FOG - 30.65 % and SO - 61.79 %. Oxygen consumption VO2 max.kg-1 was 67.44 ml.min-1, pulse oxygen 24.76 ml, post-load pH 7.24 and blood lactate concentration 6.98 mmol.l-1. There was positive correlation between CS enzyme activity and oxygen uptake (VO2 max), pulse oxygen and percentage of SO muscle fibres. The mean values found in the athletes examined in the present study corresponded to values of middle distance runners.

Adult↗
PubMed1982

Enzyme activity patterns of energy metabolism in skiers of different performance levels (M. quadriceps femoris).

Changes in the activity of muscle enzymes of energy metabolism were studied in two groups of skiers (A, B) with a different sports performance (triosephosphate dehydrogenase-TPDH, lactate dehydrogenase-LDH, glycerol-3-phosphate dehydrogenase-GPDH, hexokinase-HK, malate dehydrogenase-MDH, citrate synthase-CS, hydroxyacyl,CoA dehydrogenase-HOADH). 1. In a group of ski-runners (A) significantly higher activities of CS, MDH, HOADH in the preparatory period (October) and also at the end of the competition period (March) were found in athletes with higher sports performance. 2. Significantly lower activities of LDH, GPDH, MDH, CS, HOADH were found in downhill skiers (group B). 3. Some significant correlations were established, both between the activities of individual enzymes (TPDH, GPDH, HK, CS, HOADH) and between the enzymes and indicators of functional capacity (MDH, CS, HOADH, VO2max, HRmax, O2-pulse max, body fat, laboratory performance).

Body Composition↗
PubMed1976

Enzyme activity patterns of energy supplying metabolism in the quadriceps femoris muscle (vastus lateralis): sedentary men and physically active men of different performance levels.

1. In 3 groups of men, differing as to the amount and intensity of physical training loads, increasing in the order "sedentary": "sporting": "athletic", enzyme activities were estimated in biopsy samples of m. quadriceps femoris (vastus lateralis). The enzymes were: Hexokinase (HK), NAD: glycerol-3-phosphate dehydrogenase (GPDH), triosephosphate dehydrogenase (TPDH), lactate dehydrogenase (LDH), citrate synthase (CS), NAD: malate dehydrogenase (MDH), and 3-hydroxyacyl-CoA dehydrogenase (HOADH). Indicators of laboratory performance and whole-body metabolic capacities (maximal oxygen consumption etc.) were estimated in the "sporting" and "athletic" groups. 2. In the 2 latter groups, distinguished by greater physical activity, the atypical enzyme activity pattern, remarkable by a low activity of LDH and high relative activities of GPDH and HK, as reported earlier in a sedentary group (Bass et al., 1975a), disappeared. The possibility of the atypical low LDH enzyme activity pattern as resulting from lack of bodily exertion is discussed. 3. The moderately trained "sporting" group distinguishes itself from the "sedentary" one mainly by a higher activity of LDH and by lower activities of GPDH and MDH. In the intensively trained "athletic" group, enzymes connected to aerobic oxidation (MDH, CS, HOADH) and GPDH also show higher activities than in the "sporting" group. The difference between the two more active groups is further borne out by a higher maximum oxygen uptake and carbon dioxide release of the well-trained "athletic" group. This difference of enzyme activity pattern may not be confined to the quadriceps femoris muscle.

Adult↗