Biomedical subjects

V Bunc

Publications and source records attributed to V Bunc.

At least 19 recordsLinked to original sources

PubMed1997

Energy cost of treadmill walking.

BACKGROUND: The purpose of this study was to determine if energy cost of walking (VO2) could be accurately predicted with the simple models which analyze relationship oxygen uptake-speed of walking. A model to predict energy cost of treadmill walking was published firstly 29 years ago. METHODS: Employing the new modification of this model from 1986 to analyze VO2-speed of walking relationship leads to the elaboration of a simple linear model, two-compartment linear model, polynomial model of second order and monoexponential model of the metabolic cost of treadmill walking. To verify and compare these models 87 males, age ranged from 19 to 62 years, were evaluated on a motor driven treadmill. They walked at 0% grade at various velocities ranged from 3 to 12 km.h-1. RESULTS: The linear model has in range of intensities 3-12 km.h-1 a form of VO2.kg-1 (ml.kg-1.min-1) = 5.228*v (km.h-1)-11.158, r = 0.812, S(EE) = 4.16 ml.kg-1.min-1. The two-compartment linear model has in range of intensities of 3-7 km.h-1 a form of VO2.kg-1 = 3.207*v(km.h-1)-1.777, r = 0.932, and S(EE) = 1.5. In the range of 7.1-12 km.VO2.kg-1 = 7.120*v-29.168, r = 0.901, S(EE) = 3.78. In the range of intensities from 3 to 12 km.h-1 a polynomial model was found in the form VO2.kg-1 = 4.501-0.108*v + 0.379*v2, r = 0.891, S(EE) = 4.43, and the exponential model had a form VO2.kg-1 = 4.360*exp(0.223*v), r = 0.861, S(EE) = 6.84. All these correlation coefficients were highly significant (p < 0.001 in all cases). CONCLUSIONS: It was concluded that when applied to adult population, the models provide reasonable estimate of the actual requirement for treadmill walking provided the subjects in a oxygen uptake steady-state. As other researches for VO2/step we have found U-shaped curves of coefficient energy cost of walking. The minimum was at speed about 4 km.h-1. This finding support the speculation that does exists the "optimal" speed of moving which reflects the minimal energy expenditure during the walking.

Adult↗

PubMed1996

Physiological profile of best Czech male and female young triathletes.

To characterize the physiological profile of top young triathletes, 13 top female (mean age = 17.1 +/- 1.4 years, body mass = 58.8 +/- 4.7 kg, body height = 168.4 +/- 2.0 cm and body fat = 10.4 +/- 2.6%) and 23 top male triathletes (age = 17.7 +/- 2.2 years, mass = 66.7 +/- 7.1 kg, height = 176.5 +/- 5.1 cm and fat 8.2 +/- 2.3%) were evaluated by means of an incremental exercise (increment was 1 km.h-1, and exercise starting at 11 km.h-1 in females and 13 km.h-1 in males) on a treadmill with 5% inclination. Mean VO2max was 67.9 +/- 5.9 ml.kg-1 min-1 in boys and 56.1 +/- 2.4 ml.kg-1.min-1 in girls. mean value of maximal running speed was 18.6 +/- 1.2 km.h-1 in mean and 15.4 +/- 0.6 km.h-1 in females and LAmax was 12.5 +/- 2.3 mmol.l-1 in boys and 12.6 +/- 1.2 mmol.l-1 in girls. The selected functional variables at ventilatory threshold (VT) level in boys and girls corresponded to VO2max.kg-1 56.0 +/- 5.4 and 46.6 +/- 2.6 ml.kg-1.min-1, respectively, %VO2max.kg-1 at VT 82.4 +/- 2.1 and 83.1 +/- 1.7%, respectively, speed of running 15.2 +/- 1.4 and 12.7 +/- 0.7 km.h-1, respectively, %Vmax at VT 81.8 +/- 2.6 and 82.3 +/- 1.6%, respectively and the coefficient of energy cost of running c was 3.74 +/- 0.42 and 3.71 +/- 0.39 J.kg-1.m-1, respectively. A comparison of the functional profiles of these triathletes with elite young athletes from the sports of swimming (age 17.5 +/- 2.0 and 17.2 +/- 1.7 years, respectively, VO2max 61.6 +/- 3.6 and 52.1 +/- 3.6 ml.kg-1. min-1, respectively, Vmax 17.5 +/- 0.8 and 15.0 +/- 0.9 km.h-1, respectively, LAmax 11.1 +/- 3.2 and 11.8 +/- 3.3 mmol.l-1, respectively) cycling (17.7 +/- 1.8-17.0 +/- 1.7 years; 65.4 +/- 5.1-55.1 +/- 2.4 ml.kg-1. min-1, 18.2 +/- 0.7-15.2 +/- 0.8 km.h-1; 13.3 +/- 3.5-12.9 +/- 3.7 mmol.l-1) and middle-distance running (17.8 +/- 1.9-17.2 +/- 2.1 years; 66.8 +/- 4.7-57.3 +/- 2.6 ml.kg-1.min-1, 19.1 +/- 0.9-16.1 +/- 0.9 km.h-1; 13.1 +/- 2.6-13.7 +/- 3.0 mmol.l-1) showed the physiological characteristics of triathletes to be similar to those of middle-distance runners. According to our results and according to the data from the literature we can conclude that physiological predispositions for success in international triathlon may be as follows in boys and girls: VO2max.kg-1 higher than 65 and 60 ml.kg-1 min-1, respectively, Vmax (5%) higher than 18 and 16 km.h-1, respectively, LAmax higher than 12 and 11 mmol.l-1, respectively, running speed at "anaerobic threshold" higher than 15.0 and 13 km.h-1, respectively, %VO2max at "anaerobic threshold" level higher than 82.5% in both sexes, and the coefficient of energy cost of running lower than 3.75 and 3.73 J.kg-1.m-1, respectively. As in other sports events of an endurance native, these data are not the sole predictor of racing success. Nevertheless these standards are necessary but not sufficient conditions for success in triathlon. These data play a decisive role in the selection of talent for the triathlon.

Adipose Tissue↗

PubMed1995

[A simple method of evaluating physical fitness by means of walking].

BACKGROUND: Walking is at present the most frequently used means for purposes of rehabilitation as well as for maintenance or promotion of physical fitness. Recently we encounter with increasing frequency the use of walking as a diagnostic method for assessment of physical fitness under field conditions. The basis are motor tests of 1000 to 2000 m. The purpose of the submitted study was to prepare tables for the evaluation of the fitness level, using the 2000 m walking test and our standards of fitness. METHODS AND RESULTS: The basis of the majority of evaluations of the fitness level based on the motor test are relations between the intensity of motor activity and the maximal oxygen consumption. Using general relations between the average walking speed in the 2000 m test and the maximal oxygen consumption assessed on a treadmill in non-trained healthy men and women and base on our population standards (VO2max.kg-1) tables were elaborated. The fitness level is evaluated using the average walking speed in the 2000 m test and the appropriate maximal oxygen consumption. The tables have three grades and make it possible to evaluate men and women aged 14-65 years. CONCLUSIONS: The average speed in the 2000 m walking test makes it possible to evaluate by means of tables the physical fitness level in non-trained healthy subjects, provided the walking style is not of the racing type. The error of the estimate of physical fitness is about 15%.

Adolescent↗

PubMed1995

Verification of the heart rate threshold.

Among the methods for determining anaerobic threshold (AT), the heart rate (HR) method seems to be the simplest. On the other hand, many conflicting results from comparing this method with others have been presented over the last 10 years. Therefore, the aim of this study was to compare the heart rate threshold (HRT) with the lactate turn point (LTP)-"second" break point of dependence of lactate (LA) to power output, ventilatory threshold (VT) and threshold determined by electromyography (EMGAT), all determined by the same exercise test and evaluated by the same computer algorithm. A group of 24 female students [mean age 20.5 (SD 1.6) years, maximal oxygen consumption 48.8 (SD 4.7) ml.kg-1.min-1] performed an incremental exercise test on a cycle ergometer (modified Conconi test) starting with an initial power output (PO) of 40 W with intensity increments of 10 W.min-1 until the subjects were exhausted. The HRT, LTP and EMGAT determination was done by computer-aided break-point regression analysis from dependence of functional measures on PO. The same computer algorithm was used for VT determination from the relationship between ventilation (V) and oxygen uptake (VO2) or carbon dioxide output (VCO2).(ABSTRACT TRUNCATED AT 250 WORDS)

Anaerobic Threshold↗

PubMed1994

[Conversion of load intensity from a pedalling ergometer to a walking treadmill in patients with ischemic heart disease].

BACKGROUND: For requirements of physical rehabilitation it is important to know the "safe" load intensity: this can be assessed reliably among others on a pedalling ergometer. The purpose of the present work was to reveal conversion relations between laboratory loads on a pedalling ergometer and the load of walking which is the most natural physical activity recommended for keeping fit and for rehabilitation, incl. rehabilitation of patients with ischaemic heart disease, after cardiosurgery etc. METHODS AND RESULTS: In order to obtain conversion relations between the load intensity on a pedalling ergometer and walking on a treadmill, on the same day a group of 40 men (mean age 51.0 +/- 5.0 years, body weight 83.7 +/- 9.9 kg, height 175.3 +/- 5.8 cm and mean body fat 18.6 +/- 4.0%) were subjected to both types of exercise. All patients were for varying periods after a myocardial infarction or revascularization surgery (aortocoronary bypass type) and had different load tolerances. From the functional aspect they belonged into group NYHA I: On a single day thy were subjected to examination on a pedalling ergometer with a load of 0.75, 1.25, 1.75 W.kg-1 and on a treadmill, 0 gradient, at a rate of 3.5 and 7 km.h-1. Assuming a linear relationship between load intensity and oxygen consumption a simple relationship is found between the rate of walking in km.hour-1 and the pedalling intensity P/W.kg-1, i.e. v = 3.051 x P + 1.361. This relationship can be used for conversion of load intensities from the bicycle to walking on a treadmill or on even ground up to intensities of a pedalling load 1.75 W.kg-1 and walking at a rate of 7 km.h-1 with an error less than 10%. CONCLUSIONS: The authors elaborated a mathematically expressed general relation for conversion of the load intensity on a pedalling ergometer to walking on even ground.

Coronary Artery Bypass↗

PubMed1994

Ventilatory threshold and work efficiency during exercise on cycle and paddling ergometers in young female kayakists.

The aim of this study was to assess the effects of increasing specific (paddling ergometer) and non-specific (cycle ergometer) exercise on parameters relating to the ventilatory threshold (Th(vent)) and work efficiency in 11 young female flat-water kayakists. When these trained subjects were tested using non-specific workloads, their oxygen uptake (VO2) values at Th(vent), as a percentage of VO2max (%VO2max), were close to those of untrained subjects [74.2 (5.6) % VO2max, mean (SD)]. However, when we tested the same subjects using specific exercise, we recorded values typical of highly trained athletes [84.8 (4.7) % VO2max). For the non-specific exercise on the cycle ergometer, we recorded work efficiency values close to those of untrained subjects [22.3 (2.5) %]; however, for the specific exercise on the paddling ergometer, we recorded much lower values [13.4 (3.0) %] both at the level of Th(vent). The work efficiency at two warm-up submaximal exercise loads on the paddling ergometer was non-significantly lower than values at Th(vent) [12.3 (2.8) % and 12.9 (2.9) % respectively]. Significant correlations were found between maximal-performance VO2 (ml.kg-1.min-1) and performance at Th(vent) during paddling and race performance (0.623, 0.630 and 0.648 respectively, all P < 0.05). Because the results of both specific and non-specific submaximal exercise tests are different, we suggest caution in the interpretation of physiological variables that may be sensitive to training status. The evaluation of Th(vent) and work efficiency as supplementary parameters during laboratory studies enables the determination of the effectiveness of the training process and the specific adaptation of the subjects.

Adaptation, Physiological↗

PubMed1994

Heart rate threshold related to lactate turn point and steady-state exercise on a cycle ergometer.

The aim of this study was to investigate heart rate threshold (HRT) related exercise intensities by means of two endurance cycle ergometer tests using blood lactate concentration [La], pulmonary ventilation (VE), oxygen uptake (VO2), heart rate (HR) and electromyogram (EMG) activity of working muscle. Firstly, 16 healthy female students [age, 21.4 (SD 2.8) years; height, 167.1 (SD 5.1) cm; body mass 62.7 (SD 7.1) kg] performed an incremental exercise test (10 W each minute) on an electrically braked cycle ergometer until they felt exhausted. The HRT and lactate turn point (LTP) were assessed by means of computer-aided linear regression break point analysis from the relationship of HR or [La] to power output. No significant difference was found between HRT and LTP for all the variables measured. Secondly, two endurance tests (ET) of 20 min duration were performed by 7 subjects. The first (ET I) was performed at an exercise intensity which was about 10% lower than the power output at HRT [61.2 (SD 3.1)% maximal oxygen uptake (VO2max)], the second (ET II) at an exercise intensity about 10% higher than the power output at HRT [79.2 (SD 3.4) % VO2max]. The parameters measured showed a clear steady state in ET I. All mean values were lower than values at HRT [power, 138.7 (SD 18.9) W; HR, 172.1 (SD 4.7) beats.min-1; VO2, 2.2 (SD 0.3) l.min-1; VE, 54.0 (SD 9.1) l.min-1; [La], 3.7 (SD 1.1) mmol.l-1; EMG, 81.1 (SD 24.0) microV] except HR which was the same.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

A simple method for estimating aerobic fitness.

Physical activity is an integral part of everyday life. In order to evaluate physical fitness, there is a need for simple measures of which motor performance testing is one. The frequently used method for evaluating aerobic fitness, proposed by Cooper (1968), is based on measurements of an American population, and may involve estimating inaccuracy for aerobic fitness when used under European conditions. In this paper, tables for the estimation of aerobic fitness and physical performance are derived from a European sample (229 males, 153 females), incorporating general relations between velocity of movement and energy required for this activity expressed indirectly by oxygen consumption. The basic element of this evaluation under field conditions is the mean velocity of motion on a 2000 m track. The tables have been prepared for males and females aged 14-65 years, making it possible to estimate 'poor', 'good', and 'excellent' levels of aerobic fitness and physical performance. The error of assessment of maximal oxygen uptake and the physical fitness level varies by about 8%.

Adolescent↗

PubMed1994

Energy cost of running in young and adult female athletes.

Maximal oxygen uptake (VO2 max.kg-1) and energy cost of running were determined on the treadmill in groups of differently trained young and adult athletes. The VO2 max.kg-1 was in all cases higher in adults than in young athletes. These differences were significant (p < 0.05) in long-distance runners (n = 12, mean age = 24.2 +/- 2.2 vs 17.3 +/- 0.9 yrs, mean VO2 max.kg-1 = 66.9 +/- 4.2 vs 58.2 +/- 4.3 ml.min-1.kg-1), and in middle-distance runners (10, 22.9 +/- 2.8 vs 16, 16.6 +/- 0.8, 62.3 +/- 3.7 vs 56.1 +/- 2.8); in canoeists these differences were non-significant (7, 21.1 +/- 2.1 vs 16.0 +/- 2.3 vs 8, 48.2 +/- 2.6). Values of energy cost of running--coefficients of energy demand of running c, which indicates how much energy is required to transfer 1 kg of body mass on a distance of 1 m--were lower in adult athletes than in young athletes. These differences were significant (p < 0.05) only in long-distance runners (3.69 +/- 0.15 vs 3.84 +/- 0.14 J.kg-1.m-1). In middle-distance runners (3.67 +/- 0.19 vs 3.76 +/- 0.18), and in canoeists (3.84 +/- 0.14 vs 3.86 +/- 0.18) these differences were non-significant. It is concluded that the differences in energy cost of running between trained adult and young female athletes are probably associated with differences in adaptation to the running, and with the technique of movement. Differences in running speed (sports performance) between adult and young athletes are associated with differences in VO2 max.kg-1 and c.

Adolescent↗

PubMed1993

[Energy requirements for walking].

The energy requirement of walking, expressed indirectly by the oxygen consumption per kg body weight was assessed during different speeds of walking on a treadmill within the range of 3-12 km.h-1 in 87 untrained healthy men aged 17.5 to 60 years. The dependence of VO2.kg-1 on the speed of walking is non-linear in the mentioned range. Most suitable is the two-component linear model which in the range of 3-7 km.h-1 has the shape of VO2.kg-1 (ml.kg-1.min-1 = 3.207.v/km.h-1 - 1.777, r = 0.932 with a mean predicting error of 1.5.ml.kg-1.min-1, in the range of load of 7-12 km.h-1 VO2 = 7.120.v - 29.168, r = 0.941 with a error predicting of 3.73. The polynomic model of relations in the entire range of 3-12 km.h-1 is VO2 = 4.503 - 0.108.v + 0.379.v2, r = 0.922 with a predicting error of 4.43 ml.kg-1.min-1, and finally the exponential model has the shape VO2 = 4.360 exp (0.223.v), r = 0.861 with a mean predicting error of 6.84 ml.kg-1.min-1 in the entire range of load intensities. The justification to express the relationship between the oxygen consumption and the rate of walking by a two-component linear model as well as by non-linear models is confirmed also by the high correlation coefficient (p < 0.001 in all instances). The error of assessment of VO2.kg-1 from the speed of walking is 10% or less in all models. The mentioned models, in particular the linear one, can be used for evaluation of physical activities involving walking outdoors.

Adolescent↗

PubMed1993

Ventilatory threshold and work efficiency during exercise on a cycle and rowing ergometer.

The purpose of this investigation was to determine the effects of increasing specific (rowing ergometer) and non-specific (cycle ergometer) workloads on parameters relating to the ventilatory threshold (Tvent) and work efficiency. When highly trained male rowers were tested using non-specific workloads, their %VO2 max values at Tvent were close to those characteristic of untrained subjects (74.6 +/- 6.2% VO2 max). However, when we tested the same subjects using specific workloads, we recorded values typical of highly trained athletes (85.0 +/- 4.4% VO2 max). For the non-specific exercise on the cycle ergometer, we recorded work efficiency values close to those of untrained subjects (22.8 +/- 2.1%); however, for the specific exercise on the rowing ergometer, we recorded much lower values (16.4 +/- 3.1%). Because of the results of the non-specific submaximal exercise tests, we suggest caution in the interpretation of physiological variables that may be sensitive to training status. The evaluation of Tvent and work efficiency as supplementary parameters during laboratory studies will enable researchers to ascertain the effectiveness of the training process used, as well as indicating the specificity of the loading apparatus.

Adaptation, Physiological↗

PubMed1993

Ventilatory threshold in young and adult female athletes.

We determined in a laboratory on the treadmill the ventilatory threshold in relatively similarly trained groups of young and adult female athletes (14 adult long-distance runners mean age = 24.3 +/- 2.3 yrs; mean VO2max.kg-1 = 66.9 +/- 4.2 ml.kg-1.min-1; 11 adolescents 16.3 +/- 0.9; 58.4 +/- 4.4; 10 adult middle distance runners mean age = 22.9 +/- 2.9 yrs and VO2max.kg-1 = 62.3 +/- 3.7 ml/kg-1/min-1; 16 juniors 16.6 +/- 0.8 and 15.1 +/- 2.8; 7 adult canoeists 21.1 +/- 2.1 and 50.0 +/- 2.9; 8 adolescents 16.0 +/- 0.9 and 48.2 +/- 2.6). Maximal blood lactate concentration was found in all groups slightly lower in young athletes than in adults (in long-distance runners 10.9 +/- 2.6 vs 11.4 +/- 3.2 mmol.l-1; in middle-distance runners 12.4 +/- 2.3 vs 12.7 +/- 2.9; in canoeists 11.8 +/- 3.3 vs 12.1 +/- 3.6). The differences in maximal blood lactate concentration were nonsignificant in all groups. We did not find any significant differences in percentage of maximal aerobic power on the ventilatory threshold level. In long-distance runners the mean value of % VO2max at AT was 85.1 +/- 3.8% for adults and 84.9 +/- 2.7% for adolescents, in middle-distance runners 82.9 +/- 2.1% and 82.6 +/- 3.2%, respectively, and in adult canoeists 79.9 +/- 2.6%, and in juniors 79.4 +/- 3.0%. According to these results we can conclude that the physical activity and/or level of physical fitness seem to be main factors which may influence the values of % VO2max at VT during the growth.

Adolescent↗

PubMed1992

[Use of walking in the evaluation of aerobic fitness].

The reliability and validity of assessment of the maximal oxygen consumption as a criterion of aerobic fitness by the 2000 m walking test was established in 38 students of the military secondary school (mean age 17.8 +/- 0.4 years). The reliability of the 2000 m walking test is very high, during repeated estimations in the course of one week we find a correlation coefficient of r = 0.82 (p < 0.001). There is also a close correlation of 2000 m walking time and 2000 m running time (r = 0.67, p < 0.001). A group of 18 students selected at random from the above group was examined in the laboratory on a treadmill up to vita maxima. A close correlation was found between the results during walking and the maximal oxygen consumption (VO2max.kg-1) (r = -0.59 and -0.60) and also the 2000 m running time and VO2max.kg-1 (r = 0.59), p < 0.01 in all instances. The standard error of the mean of the maximal oxygen consumption estimate from the 2000 m walk is 3.44 ml.kg-1 x min-1 (5.7%) and from the running time of the same distance 3.49 ml.kg-1 x min-1 (5.8%). These results justify the conclusion that the 2000 m rapid walking test (normal style) is a simple alternative way for estimating the maximal oxygen consumption and thus also for evaluating the level of aerobic fitness with an accuracy which matches that, when running is used for the test.

Adolescent↗

PubMed1992

Assessment of predispositions for endurance running from field tests.

Field tests of speed and endurance may be used to evaluate the probability of success and to create efficient training strategies for sports. Currently, both invasive and non-invasive methods are used for this purpose. While invasive methods cause some discomfort to subjects, non-invasive methods may employ practices associated with the sport itself. One such method employs the linear relationship between exercise intensity or running speed and distance covered running at that speed represented on a semi-logarithmic scale. The separation of endurance runners into three different groups can be confirmed by different values for the slope coefficient (b) of this linear relation. According to findings among top Czechoslovak endurance runners, supplemented by the data of other authors, the values of coefficient b in middle-distance runners are in the range -2.166 to -1.700, in long-distance runners -1.520 to -1.050 and in marathon runners -0.836 to -0.436. Similarly, a separation of young endurance runners into groups of middle-distance and long-distance runners must be within the range -2.158 to -1.800 and for young long-distance runners -1.700 to -1.300. Based on these findings, the optimum competitive distance for adult athletes can be established in relation to current training status. In young athletes, it is possible to select gifted runners with predispositions for middle-distance and long-distance running. For both groups of athletes, more efficient training methods can be selected to optimize their predispositions for maximal performance.

Adult↗

PubMed1991

[Conversion of the intensity of loading from the bicycle ergometer to a treadmill and to field training in women].

When evaluating the standard of functional fitness, state of training or work capacity of subjects, when diagnosing loads, when assessing training of healthy subjects and sportsmen and locomotor rehabilitation of patients usually two types of ergometers are used--a pedalling ergometer and a treadmill. Each of these ergometers has its specific properties, advantages and shortcomings. For the practical use of results of functional examination in the laboratory, where the majority of our diagnostic departments possesses only a pedalling ergometer it is necessary to convert the load intensity from the bicycle to a treadmill and to the field where physical training is usually implemented. Based on our measurements in groups women with different grades of training, differing as to age, it is possible to elaborate a general equation which relates the load intensity on the pedalling ergometer P/W.kg-1 and the speed of running on the treadmill with a zero gradient v/km.h-1 in the form v = 3,695.P-1,419. This relationship can be used with an error of cca 12% in the zone of submaximal load intensities (up to 90% of the maximal load intensity). For P lower than 3.9 W.kg-1 this equation can be used for direct conversion to flat ground. For higher load intensities there is the relationship v = 3,156.P + 0.446 which has the same error of 12% as for even ground.

Adolescent↗

PubMed1991

[Energy requirements in women during pedalling on a bicycle ergometer].

The bicycle ergometer is the most frequently used equipment for loading tests for the purpose of functional diagnosis and for the purpose of locomotor rehabilitation. The energy required to meet this locomotor activity is within a wide range of load intensities which depends linearily on the intensity of pedalling. The steepness of this linear relationship which characterizes the degree of adaptation of the organism to this type of locomotor activity is the smaller the more the investigated subjects are adapted to the load. In general it depends on the degree of training, age, sex, strength, pedalling frequency, on the load protocol and on the biomechanical conditions during pedalling (e.g. the height of the saddle). Based on our measurements in a group of untrained women of different age and in trained women of different age it can be demonstrated that all individual relations between energy characterized by means of VO2 and the intensity of the load - P is within the zone where the upper borderline is formed by the equation VO2(ml) = 11.00.P (W) + 403 and the lower borderline by VO2(ml) = 9.90.P (W) + 252. The basic relationship, independent on the degree of training, age and strength, valid in the zone of pedalling frequencies of 60-80 rot. min-1 and in the zone of load intensities of 75-325 W has the shape of VO2(ml) = 10.60.P(W) + 269. The maximum error of assessment of VO2 by means of the load intensity is 9% or less.

Adolescent↗

PubMed1991

[Anaerobic "all-out" stress tests: selection of the type and duration of stress].

In the diagnosis of prerequisite conditions for short-term highly intensive activity, performed under conditions of oxygen deficit anaerobic loading tests are used. Contrary to tests of constant performance, "all-out" tests follow up changes of performance in the course of time, i. e. they record the maximal anaerobic performance as well as the decline of performance in the course of the test. In a group of 17 subjects three types of loads were compared (bicycle ergometry, a test repeated jumps and running) and two periods of anaerobic tests--45 s and 120 s. The results achieved in different tests--total work, maximum performance, decline of performance, post-load lactate concentration in blood--differed depending on the type of load and duration of the test. Correlation analysis did not reveal a close relationship between the results of different anaerobic tests, there was however a relationship between the maximum performance and the total work at the level of general physical fitness. The longer variant of the test--120 s--did not prove more suitable, neither from the aspect of the assumed markedly higher lactate cumulation in blood nor from the aspect of maximum performance, as compared with the 45 s test. A close relationship was revealed between the results of the 45 s and 120 s jumping and running test but not between the results of bicycle ergometry. The post-load lactate concentration cannot be considered a highly reliable indicator of the level of the anaerobic energy metabolism in the working muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Ventilatory threshold and work efficiency on a bicycle and paddling ergometer in top canoeists.

The purpose of this investigation was to determine the effect of increasing specific (paddling ergometer) and non-specific (bicycle ergometer) work load on the parameters at the ventilatory threshold (VT) and on work efficiency (WE) during increasing exercise ergometry. When highly trained male canoeists were given an unspecific exercise load, the values of %VO2max at VT were close to the values characteristic for an untrained population (72.3 +/- 5.3% VO2max). When the same subjects were given a specific work load, they produced values typical for highly trained athletes (83.4 +/- 2.5% VO2max). Non-specific exercise produced WE values close to those of untrained subjects on the bicycle ergometer (23.3 +/- 2.1%), and when loading is specific, the groups of working muscles are smaller, producing lower WE values (14.7 +/- 3.5%). It was concluded that the responses to submaximal exercise intensities in the case of nonspecific loading suggests caution in the interpretation of physiological variables which may be sensitive to training status. The assessment of VT and WE as supplementary characteristics during laboratory measurements, enables us, along with other parameters, to ascertain not only the effectiveness of the training process used, but also the specificity of a loading apparatus.

Adaptation, Physiological↗