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Biomedical subjects

V Bunc

Publications and source records attributed to V Bunc.

At least 19 recordsLinked to original sources
PubMed2006

[Motor skills testing in patients with chronic renal failure].

BACKGROUND: During chronic renal failure, number of complex metabolic and endocrinal changes in organism can develop, which in consequence lead to an inception of associate complications and in principle change the activity of all organ systems. Functional capacity of the chronically dialysed patients is limited, muscle strength is decreased, joint mobility is limited and the muscular imbalance is frequently found. According to the recent literature, an acceptable choice of exercise activity could contribute to prevention of disturbances and improve the patient's status. An essential part of each exercise program for these patients is an acceptable motor tests battery (1, 2, 3, 4, 5, 6 and 7). The aim of our study was to choose an acceptable motor tests battery, which should target such components of motor performance, whose certain rate is necessary for self-sufficiency keeping and perform activities of daily living. METHODS AND RESULTS: We observed mixed group of 23 patients. For evaluation of the functional condition we used the "Senior Fitness Test Manual" (8), which measures these physical attributes: muscle strength, physical endurance, flexibility, agility and balance. The input results we compared with population standard specification used in the test battery. Results of the tests showed that the group of patients in comparison with the population standard specification have reached subnormal and risk performances, especially in tests requiring for its implementation muscular strength of lower extremities and physical efficiency. Normal and above normal performances we observed in patients that were physically active before and during regular dialysis treatment. CONCLUSIONS: After the evaluation of result, we consider the selected battery of motor tests as an acceptable choice for motor skills testing in renal dialysed patients all age categories.

Adult↗
PubMed2004

[The use of bioimpedance analysis for the assessment of relative body fat in obese women].

BACKGROUND: Bioimpedance analysis (BIA) is often used for the assessment of relative body fat (%BF). The accuracy of the test depends on prediction equation used, which respects the group of population, body composition, age and gender of the individual. The requirement to construct a specific prediction equation for obese population with more than 30% body fat was suggested. The objective of the study was to evaluate the validity of bioimpedance analysis and to develop population-specific prediction equation for obese women. METHODS AND RESULTS: Relative body fat were measured in set of 63 obese women by means of 3 methods: tetrapolar bioimpedance analysis, bipedal bioimpedance analysis and dual energy X-ray absorbtiometry (DEXA). Significant differences were found among mean values of %BF measured by methods above (39.9%, 42.2% and 48.7%, respectively). Significant correlation between results obtained by tetrapolar BIA and by DEXA method was noticed (R=0.73). New specific prediction equation was developed for measuring %BF of obese women by tetrapolar BIA. No good agreement between bipedal BIA and DEXA method was found. CONCLUSIONS: By using the new prediction equation, measurement of the relative body fat in obese women by tetrapolar bioimpedance analysis was comparable with the reference DEXA method.

Absorptiometry, Photon↗
PubMed2004

[Effect of body composition on physical fitness and functional capacity in obese women].

BACKGROUND: Both the high body fatness and low aerobic fitness have been shown to be risk factors for cardiovascular disease and type 2 diabetes. It is still unclear, whether these factors are related to each other or if they are independent risk factors. The objective of this study was to assess the influence of body composition on aspects of aerobic fitness in obese women. METHODS AND RESULTS: Relative body fat was measured in a group of 31 obese women differing in age (25-54 years) by dual energy X-ray absorbtiometry (DEXA), in range of 40,8-58,8% of the body fat. Intracellular and extracellular fractions of the fat free mass were assessed by bioimpedance analysis. Maximal power output and maximal oxygen consumption were measured by stepwise load test on bicycle ergometer. Mean values of absolute and relative VO2max expressed per kg body mass and per kg fat-free mass were 2,09+/-0,38 l x min(-1), 22,82+/-3,79 ml x min(-1) kg(-1), and 44,05+/-7,03 ml x min(-1) x kg(-1), respectively. Absolute VO2max was positively related to body weight (R=0,4758; P<0,01), BMI (R=0,5004; P<0,01), fat-free mass (R=0,5138; P<0,01) and body cell mass (R=0,4983; P<0,01). No significant dependence of relative VO2max per kg body mass on the body fat was identified. CONCLUSIONS: Aerobic fitness, expressed by relative maximal oxygen consumption per kg of body weight, is not influenced by the percent of body fat in obese women. Body cell mass is markedly related to aerobic fitness, expressed by absolute maximal oxygen consumption in obese women.

Adult↗
PubMed2001

Physiological profile of very young soccer players.

BACKGROUND: There is still much uncertainty and debate surrounding the physiological requirements of competitive soccer. The coaching emphasis on skill development, deficiencies in fitness training, conservative training methods lead to difficulty in the scientific study of soccer. METHODS: The physiological profiles of 22 young soccer players (mean age = 8.0+/-0.3 years, body mass = 28.2+/-3.2 kg, body height = 132.4+/-4.3 cm and body fat = 19.4+/-1.6 percent) were measured by the incremental exercise protocol on the treadmill with 5 percent inclination. All boys systematically trained at least 2 years with a minimum of two training units per week. During preseason, they trained two times per week, and during the competitive season they trained at least three times and competed in one or two games per week. RESULTS: Mean VO2max x kg(-1) was 56.7+/-4.9 ml x kg(-1) x min(-1). Mean value of maximal running speed on a treadmill with 5 percent of inclination was 12.0+/-0.9 km x h(-1). Mean values of Rmax = 1.11+/-0.07. The selected functional variables at the ventilatory threshold (VT) level corresponded to VO2 x kg(-1) = 42.9+/-5.0 ml x kg(-1) x min(-1), mean values of percent VO2max x kg(-1) at VT level were 76.5+/-1.3 percent, mean speed of running was 10.5+/-1.2 km x h(-1), mean values of percent Vmax at VT level were 87.5+/-1.9 percent. The mean of energy cost of running was 4.28+/-0.19 J x kg(-1) x m(-1). According to our results, we can conclude that the physiological characteristics of young soccer players about 8 years old should be as follows: VO2max x kg(-1) higher than 55 ml x kg(-1) x min(-1) in defenders, and higher than 60 ml x kg(-1) x min(-1), in midfielders and forwards. Maximal speed of running on the treadmill with 5 percent of inclination should be higher than 12 km x h(-1) in all players, the running speed at anaerobic threshold (5 percent) higher than 10.5 km x h(-1), percent VO2max at anaerobic threshold level higher than 77.0 percent, and the energy cost of running lower than 4.20 J x kg(-1) x m(-1). CONCLUSIONS: As in other sports where skills play a decisive role, the physiological data cannot be the sole predictor of competitive success. On the other hand, we must note that these physiological norms and standards are necessary conditions for success in high levels of soccer competition. The norms play decisive role in talent selection.

Adipose Tissue↗
PubMed2000

Walking in visually handicapped children and its energy cost.

Walking is a basic activity in visually handicapped subjects, and often it is used as a general means of improving physical fitness. The level of adaptation to walking may be assessed by means of energy cost, c. The variable c was studied during walking on a treadmill in two groups of visually handicapped children (international classification of vision of 5/200 or less). The two groups were comprised of 15 boys (mean age = 11.8 +/- 2.1 years) and 13 girls (mean age = 11.6 +/- 3.1 years). The mean energy cost in boys was found to be 3.79 +/- 0.31 J kg(-1) m(-1) and in girls it was 3.77 +/- 0.36 J kg(-1) m(-1). Both these values were not significantly higher than the energy cost in untrained nonhandicapped children of the same age. There was a U-shaped dependence of c on increased speed of walking. The minimum was about 3.6 km h(-1) in both groups of handicapped children, which was similar to that for non-handicapped subjects. It is concluded that in visually handicapped children the energy cost of walking, and thus adaptation to walking, is the same as in the healthy children. The visually handicapped individuals show a 'normal' response to exercise, to which they are adapted, with increases in both cardiovascular and muscular fitness.

Adaptation, Physiological↗
PubMed2000

Energy cost of treadmill running in non-trained females differing in body fat.

BACKGROUND: The energy demands of movement may be characterised by the energy cost C, which indicates how much energy is needed to carry a body mass of 1 kg over a distance of 1 m. It is generally accepted that the lower C represents a lesser amount of mechanical work executed with the same efficiency. The purpose of this study was to assess the influence of body fat on energy cost of running in healthy non-trained females. METHODS: Energy cost of running (C) was determined on the treadmill in a group of healthy non-trained females (N=63, mean age=39.+/-10.2 years, body mass=64.6+/-5.5 kg, height= 166.2+/-5.7 cm, VO2max.kg(-1)=35.0+/-3.6 ml.kg(-1)min(-1)), differing significantly in the percentage of body fat (18.9-30.2%), assessed by the 10 skinfold measurements. RESULTS: Mean value of C was 3.97+/-0.07 J.kg(-1)m(-1). The lowest values of C were found in subjects with the lowest %BF (C ranged from 3.81 to 4.06 J.kg(-1).m(-1)). There is a significant positive correlation between C and %BF [C (J.kg(-1).m(-1))= 0.0185*%BF (%) + 3.5090; r=0.7805; p<0.001; r2=0.6091], C and body mass (BM) [C (J.kg(-1).m(-1)) = 0.0083*BM (kg) + 3.4384; r=0.6176; p<0.001; r2 = 0.3814], and C and free fat mass (FFM) [C (J.kg(-1).m(-1))=0.0087*FFM (kg) + 3.5543; r=0.3521; p<0.05; r2=0.1240]. There is a negative correlation between C and VO2max.kg(-1) [C (J.kg(-1).m(-1))=-0.0181* VO2max.kg(-1) (ml.kg(-1).min(-1)) +4.6071; r=-0.8810; p<0.0001; r2=0.7761], and VO2max.kg(-1) and %BF [VO2max.kg(-1) (ml.kg(-1).min(-1)) =-0.8401* %BF(%) + 54.1021; r=-0.7142; p<0.0001; r2=0.5101]. CONCLUSIONS: From the collected data for untrained females we may conclude: first, the higher the training state (VO2max.kg(-1)), the lower the energy cost of running. Second, the energy cost of running C increases with the increase in body mass, %BF and FFM. Third, the training state decreases (VO2max.kg(-1)) with the increase in %BF.

Adipose Tissue↗
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↗