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1.
G. Kaczmarczyk H. W. Reinhardt J. Riedel R. Eisele M. Gatzka U. Kuhl 《Pflügers Archiv : European journal of physiology》1977,368(1-2):181-184
Summary 5 conscious, well trained, female dogs kept on a high sodium intake (14 meq Na/kg bw) were used to measureeft atrial pressure (LAP), urine volume (
), sodium and potassium excretion (UNa
, UK
) as well as plasma osmolality (Posm) before and up to 180 minafter food intake. The dogs were fitted with a catheter in the left atrium (thoracotomy). In all experiments (n=23) LAP increased postprandially (pp) above fasting controls. The mean peak increase range from 4 to 6 cm H2O and was observed as early as 61–80 and as late, as 161–180 min pp. Increase in LAP was closely correlated to V which rose from 36±28 to 160±51 ul/min·kg. pp
was also correlated to pp UNa
which increased from 4.8±3.3 to 34.0±8.5 ueq/min·kg.The pp increase in LAP and its close relation to pp
and pp UNa
emphasize the assumption that intrathoracic receptors are involved in the regulation of body fluids. 相似文献
2.
Summary To investigate the effect of hyperthyroidism on the pattern and time course of O2 uptake (
O2) following the transition from rest to exercise, six patients and six healthy subjects performed cycle exercise at an average work rate (WR) of 18 and 20 W respectively. Cardiorespiratory variables were measured breath-by-breath. The patients also performed a progressively increasing WR test (1-min increments) to the limit of tolerance. Two patients repeated the studies when euthyroid. Resting and exercise steady-state (SS)
O2 (ml·kg–1·min–1) were higher in the patients than control (5.8, SD 0.9 vs 4.0, SD 0.3 and 12.1, SD 1.5 vs 10.2, SD 1.0 respectively). The increase in
O2 during the first 20 s exercise (phase I) was lower in the patients (mean 89 ml·min–, SD 30) compared to the control (265 ml·min–1, SD 90), while the difference in half time of the subsequent (phase 11) increase to the SS
O2 (patient 26 s, SD 8; controls 17 s, SD 8) were not significant (P = 0.06). The OZ cost per WR increment (
O2/WR) in ml·min–1·–1, measured during the incremental period (mean 10.9; range 8.3–12.2), was always within two standard deviations of the normal value (10.3, SD 1). In the two patients who repeated the tests, both the increment of
O2 from rest to SS during constant WR exercise and the
O2/WRs during the progressive exercise were higher in the hyperthyroid state than during the euthyroid state. While both resting and exercise
O2 are increased in the hyperthyroid patients, the O2 cost of a given increment of WR is within the normal range. However, a small reduction in the
O2 requirement to perform exercise following treatment of the hyperthyroid state suggests a subtle change O2 cost of muscle work in this disease. 相似文献
3.
Summary An indirect test of maximal aerobic power (IMAP) was evaluated in 31 healthy male subjects by comparing it with a direct treadmill measurement of maximal aerobic power (
O2 max), with the prediction of
O2 max from heart rate during submaximal exercise on a cycle ergometer using åstrand's nomogram, with the British Army's Basic Fitness Test (BFT, a 2.4 km run performed in boots and trousers), and with a test of maximum anaerobic power. For the IMAP test, subjects pedalled on a cycle ergometer at 75 revs·min–1. The workload was 37.5 watts for the first minute, and was increased by 37.5 watts every minute until the subject could not continue. Time to exhaustion was recorded. Predicted
O2 max and times for BFT and IMAP correlated significantly (p<0.001) with the direct
O2 max: r=0.70, r=0.67 and r=0.79 respectively. The correlation between direct
O2 max and the maximum anaerobic power test was significant (p<0.05) but lower, r=0.44. Although lactate levels after direct
O2 max determination were significantly higher than those after the IMAP test, maximum heart rates were not significantly different. Submaximal
O2 values measured during the IMAP test yielded a regression equation relating
O2 max and pedalling time. When individual values for direct and predicted
O2 max and times for BFT and IMAP were compared with equivalent standards, the percentages of subjects able to exceed the standard were 100, 65, 87, and 87 respectively. These data demonstrate that the IMAP test provides a valid estimate of
O2 max and indicate that it may be a practical test for establishing that an individual meets a minimum standard. 相似文献
4.
Criteria for maximum oxygen uptake in progressive bicycle tests 总被引:1,自引:0,他引:1
K. NiemelÄ I. Palatsi M. Linnaluoto J. Takkunen 《European journal of applied physiology》1980,44(1):51-59
Summary Different criteria for
O2 max in a progressive bicycle exercise were studied in 115 healthy subjects. In the repeated progressive tests performed on 16 men, aged 25–35 years, three types of
O2 response against work load were noticed: a linear increase, an unexpectedly high increase, and a plateau; the last two only appearing when
O2 max was achieved. The last three
O2 values at least were required to define the plateau. Most commonly, subjective exhaustion was achieved, respiratory quotient (R) was over 1.15 and maximal heart rate (HR) at the estimated level for age, though
O2 max was not achieved. No significant differences were found between peak
O2 in the first progressive test (mean=2.95 l/min), the second progressive test (mean=3.14 l/min), or the constant-load test (mean=3.05 l/min). In the progressive test performed once on 55 men and 44 women, aged 35–62 years, subjective exhaustion was achieved by most of the subjects, but the plateau in
O2 was shown only in 17 subjects, and the peak
O2 values were somewhat lower than expected. Moreover, R max did not correlate with peak
O2, and was over 1.15 only in 9 subjects, and HR max was often below the estimated level. Thus, the progressive test appeared to be convenient in testing the physical work capacity of the subjects, but the establishment of the physiological maximum was more difficult: the relatively uncommon plateau in
O2 was the only useful criterion for
O2 max, the value of other criteria being unacceptable. 相似文献
5.
Claude Bouchard Robert M. Malina Wildor Hollmann Claude Leblanc 《European journal of applied physiology》1977,36(2):115-126
Heart diameters, heart volume (HV), PWC
130,
O2 at 130 heart rate, and cardiorespiratory reactions during work at 3 kgm·s–1 were obtained in 237 boys ranging in age from 8–18 years. Results indicate that heart size, PWC
130,
O130, and exercise HR,
O2/HR,
and SBP change significantly with age. On the other hand, HV·kg–1 and work
O2,
E and
E/
O2 remain rather stable throughout the growth period.Correlation analysis indicates that about 85% of the observed variation in the size of the heart during growth can be accounted for by body weight, while about 70% of the variation in light submaximal working capacity (
O130) can be explained by HV alone. Holding age, height and body weight constant by partial correlation procedures yields significant relationships between HV and
O130 (r = 0.461), and between HV·kg–1 and
O130 (r = 0.414). Age, height, weight and size of the heart correlated simultaneously against
O130 account for 75% of the variance in the dependent variable.It would seem important to suggest the need for study of the interactions between age, size and maturity, in addition to indicators of size and efficiency of the oxygen delivery system, and indices of muscle oxygen utilization efficiency. Such an approach will permit a more definite partitioning of the variance in submaximal aerobic capacity during growth, and would probably yield a more conservative estimate of the relationship between the size of the heart and submaximal working capacity during growth.Abbreviations used
HV
heart volume
-
HV·kg–1
heart volume per kg of body weight
-
PWC
130
physical working capacity in kgm·s–1 of work at a heart rate of 130·min–1
-
O130
oxygen consumption per min at a heart rate of 130·min–1
-
O2,
,
E,
E/
O2, HR,
O2/HR, SBP
oxygen consumption, breathing frequency, expiratory volume, respiratory equivalent, heart rate, oxygen pulse, systolic blood pressure in the third minute of work at 3 kgm·s–1
-
CA
chronological age
Partially supported by grants from the Kuratorium für die Sportmedizinische Forschung, Federal Republic of Germany and Laval University, Quebec, Canada 相似文献
6.
K. Chamari S. Ahmaidi C. Fabre M. Ramonatxo C. Préfaut 《European journal of applied physiology》1995,70(5):442-450
To investigate pulmonary gas exchange and ventilatory responses to brief intense intermittent exercise and to study the effects of physical fitness on thes responses, nine trained and nine untrained healthy male subjects aged 18–33 years performed the force-velocity (F-) exercise test. This test consisted of 6-s sprints against increasing braking forces (F) separated by 5-min recovery periods. Oxygen uptake (
), carbon dioxide output (
CO2), and ventilation
E) were continuously measured during the test and the magnitudes of their responses to the sprints were then calculated.For all subjects
CO2 increased rapidly after beginning the sprints, and the peaks of the responses (F = 13.4;P < 0.001), end of recovery values (F = 6.5;P < 0.01), and
O2 magnitudes of response (F = 12.4;P < 0.001) rose significantly with the repetition of the sprints. The
O2 magnitudes of response correlated with the corresponding sprint power outputs (r = 0.55;P < 0.001) and with the sprint repetitions (r = 0.51,P < 0.001). The
CO2 (F = 7.1;P < 0.01) and {ie442-8} (F = 5.0;P < 0.01) peaks of response increased with the initial load incrementation, then stabilized when the subjects attained peak power output. End of recovery
CO2 (F = 18.0;P < 0.001) and
E (F = 14.1;P < 0.001) values rose with increasingF. TheF- peak
O2,
CO2,
E, tidal volume and respiratory frequency responses attained 53%, 40%, 44%, 66%, and 82% of the peak values measured at exhaustion of maximal graded exercise, respectively.Trained and untrained subjects had the same first sprint power output and braking, force. Nevertheless, the trained subjects had higher
O2 peaks (F = 35.2;P < 0.001) and
CO2 magnitudes of response (F = 30.0;P < 0.001) than the untrained subjects for all sprints. The higher peak
O2 values represented similar percentages of maximal oxygen uptake in the trained and untrained subjects. In summary, the present study showed that in brief intense intermittent exercise, i.e. theF- test, the
O2,
CO2, and ventilatory responses in young subjects were submaximal with respect to the peak values attained at exhaustion of maximal graded exercise. The
CO2 magnitude of response increase was related to the power output rise in the corresponding sprints and to the repetition of sprints. Moreover, the trained subjects presented higher
CO2 peaks and magnitudes of response to the sprints than the untrained subjects. 相似文献
7.
Maria T. E. Hopman Menno Pistorius Ingrid C. E. Kamerbeek Rob A. Binkhorst 《European journal of applied physiology》1993,66(6):531-535
Summary The purpose of this investigation was to compare cardiac output (
c
) in paraplegic subjects (P) with wheelchair-confined control subjects (C) at high intensities of arm exercise. At low and moderate exercise intensity
c
was the same at a given oxygen uptake (
O2) in P and C. A group of 11 athletic male P with complete spinal-cord lesions between T6 and T12 and a group of 5 well-matched athletic male C performed maximal arm-cranking exercise and submaximal exercise at 50%, 70% and 80% of each individual's maximal power output (Wmax) . Maximal
O2 (
O2max) was significantly lower,
O2max per kilogram body mass was equal and maximal heart rate (f
c) was significantly higher in P compared to C. At
O2 of 1.3, 1.5 and 1.7 1-min–1, and for P 65%–90% of the
O2max,
c
was not significantly different between the groups, although,
c
in P was achieved with a significantly lower stroke volume (SV) and a significantly higherf
c. Although the SV was lower in P, it followed the same pattern as SV in C during incremental exercise, i.e. an increase in SV until about 45%W
max and thereafter a stable SV. The similar
c
at a given
O2 in both groups indicated that, even at high exercise intensities, circulation in P can be considered isokinetic with a complete compensation byf
c for a lower SV. 相似文献
8.
A. Lucas A. Therminarias M. Tanche 《Pflügers Archiv : European journal of physiology》1980,388(1):83-87
Maximum oxygen consumption for a short exhaustive work (Ex
max) and for a severe cold stress (Ex
max) were investigated in 8 dogs. Heart rate, plasma catecholamines and substrate concentrations were measured under both conditions. Mean C
was lower than mean Ex
max. Heart rate and plasma lactate were also lower during cold exposure than during exercise. Average plasma epinephrine concentrations were not significantly different and average plasma norepinephrine concentrations were similar under C
and Ex
max conditions. A positive correlation was found between plasma lactate and epinephrine concentrations measured under both conditions.It may be assumed that maximum oxygen consumption during muscular exercise is higher than during shivering thermogenesis. This difference does not seem to be due to differences in the involvement of the sympathico-adreno-medullary system. 相似文献
9.
Dr. C. A. Williams J. S. Petrofsky A. R. Lind 《European journal of applied physiology》1982,50(1):133-144
Summary Physiological responses were measured in 7 women subjects who lifted boxes weighing 6.8, 15.9 or 22.7 kg from the floor to a height of 60 cm. After training and establishing the
O2 max, the boxes were lifted for 1 h at 30, 50, and 60%
O2 max. The changes in heart rate,
O2, the integrated EMG during lifting and the loss of isometric hand-grip endurance after lifting were used to assess the development of fatigue. There was no evidence of fatigue at 30%
O2 max but fatigue did exist in some conditions at 50% and in all conditions at 60%
O2 max. It is suggested that fatigue is unlikely to occur while lifting boxes up to 15.9 kg weight at 35–40%
O2 max, i.e., at rates of lifting varying from 5 to 7 times per min. 相似文献
10.
Summary The method described by Wasserman for anaerobic threshold (AT) determination, based on the recording of ventilatory parameters, was supported by the simultaneous appearance of hyperlactacidemia and hyperventilation during a standardized incremental work test. Our study aimed at testing the AT in another profile of exercise, viz., during exercises at constant workloads.A homogenous population of 66 healthy subjects performed on a treadmill a total of 100 exercises of 20 min duration at constant workloads (43, 48, 52, 57, 63, and 71%
O2max). The
O2,
, and venous plasma lactic acid (LA) were determined every minute.LA showed an initial transient increase at 43%
O2 max and a steady-state elevated level above 48%
O2 max. In contrast, the hyperventilation threshold (HVT) was only observed above 57%
O2 max, simultaneously with a delayed steady-state
O2 and with a sustained increase of lactate until the end of exercise.The meaning of the simultaneity of these three events must still be studied. However, the dissociation between both early and steady-state lactate thresholds and HVT is not in keeping with the concept of AT. In these conditions, there is no evidence that HVT necessarily represents an AT, viz., a critical intensity of exercise inducing an insufficient oxygen delivery to the muscles. This conclusion does not imply that the measurement of HVT should be rejected as an empirical test of physical fitness. 相似文献
11.
Toshifumi Watanabe Terence F. McDonald 《Pflügers Archiv : European journal of physiology》1986,406(6):645-647
The action potential configuration in guinea pig ventricular myocytes was unaffected by low concentrations (0.3–1 M) of tetrodotoxin (TTX); high concentrations (10–30 M) depressed both the overshoot (5–10 mV) and duration (5–10%). Although the control
was unaffected by stimulation rate (0.1–5 Hz), the depression of
by TTX was greatly potentiated at rates above 1 Hz: on dose-response curves, 50% control
occurred at 4.3 M (5 Hz) versus 22 M ( 1 Hz). The frequency dependent component of the
depression reported here is much larger than the extra block of Na channels observed by others in voltage clamp studies on Purkinje strands. This is not a discrepancy; rather it is a consequence of a non-linear relation between
and available Na conductance. 相似文献
12.
Noninvasive measurement of human forearm oxygen consumption by near infrared spectroscopy 总被引:5,自引:0,他引:5
Roberto A. De Blasi Mark Cope Clare Elwell Fauzia Safoue Marco Ferrari 《European journal of applied physiology》1993,67(1):20-25
Summary This study reported on the application of near infrared spectroscopy (NIRS) to noninvasive measurements of forearm brachio-radial muscle oxygen consumption (
O2) and recovery time (t
r) in untrained volunteers. Seven healthy subjects were submitted to four consecutive protocols involving measurements made at rest, the induction of an ischaemia, and during a maximal increase of metabolic demand achieved with and without vascular occlusion. Two isometric maximal voluntary contractions (MVC) of 30-s duration were executed with and without vascular occlusion and a 50% MVC lasting 125 s was also performed. The protocols were repeated on 2 different days. The results showed that, during vascular occlusion at rest, the time to 95% of the final haemoglobin (Hb) + myoglobin (Mb) desaturation value was independent of
O2. The MVC, performed during vascular occlusion, caused complete Hb + Mb desaturation in 15–20 s, which was not followed by any further desaturation when the second contraction was performed. No difference was found between
O2during MVC with and without vascular occlusion. A consistent difference was seen between
O2measured during occlusion at rest and
O2measured during MVC with and without occlusion. During prolonged exercise (125 s) Hb + Mb desaturation was maintained for the whole contraction period. The results of this study show that
O2can be measured noninvasively by NIRS. The
O2during MVC was very similar both in the presence and absence of blood flow limitation in most of the subjects tested. This would suggest that muscle
O2might be accurately evaluated dynamically without cuff occlusion. 相似文献
13.
Yoshiyuki Honda Namiyo Hata Yoshikazu Sakakibara Takashi Nishino Yoichi Satomura 《Pflügers Archiv : European journal of physiology》1981,391(4):289-295
Hypoxic-hypercapnic interaction in mild hypoxia was studied in 12 healthy males. Steady state ventilatory responses to hypercapnic-hypoxia
were obtained as the difference in ventilation between hypoxia (mean values ± S.D. of
=7.36±0.20 kPa or of
7.10 ±0.41 kPa) and hyperoxia (
>26.7 kPa) with the same degree of hypercapnia (
6.12±0.22 kPa). On the other band, withdrawal responses
were obtained as the magnitude of depression in ventilation caused by two bicaths of O2 from the above mentioned hypoxic hypercapnia. Averaged
and
were 9.57±5.45 and 6.45 ±4.90l/min, respectively, the difference being statistically significant (P<0.01). Furthermore, if we assume the presence of ventilatory depression to be due to tissue
fall resulting from an increase in cerebral blood flow caused by hypoxia, the magnitude of central hypoxic-hypercapnic interaction was estimated to be as great as the value of
. 相似文献
14.
Takayoshi Yoshida Koji Yamamoto Masao Udo 《European journal of applied physiology》1993,66(2):155-160
Summary The purpose of the present study was to assess the relationship between the rapidity of increased gas exchange (i.e. oxygen uptake
) and increased cardiac output (
) during the transient phase following the onset of exercise. Five healthy male subjects performed multiple rest-exercise or light exercise (25 W)-exercise transitions on an electrically braked ergometer at exercise intensities of 50, 75, or 100 W for 6 min, respectively. Each transition was performed at least eight times for each load in random order. The
was obtained by a breath-by-breath method, and
was measured by an impedance method during normal breathing, using an ensemble average. On transitions from rest to exercise,
rapidly increased during phase I with time constants of 6.8–7.3 s. The
also showed a similar rapid increment with time constants of 6.0–6.8 s with an apparent increase in stroke volume (SV). In this phase I,
increased to about 29.7%–34.1% of the steady-state value and
increased to about 58.3%–87.0%. Thereafter, some 20 s after the onset of exercise a mono-exponential increase to steady-state occurred both in
and
with time constants of 26.7–32.3 and 23.7–34.4 s, respectively. The insignificant difference between
and
time constants in phase I and the abrupt increase in both
and SV at the onset of exercise from rest provided further evidence for a cardiodynamic contribution to
following the onset of exercise from rest. 相似文献
15.
A. C. M. Schrikker H. Wesenhagen S. C. M. Luijendijk 《Pflügers Archiv : European journal of physiology》1993,425(1-2):16-21
To investigate the effect of incomplete gas mixing between tidal air and residual gas on pulmonary gas exchange, anaesthetized dogs were ventilated artificially with breathing patterns with different durations of the post-inspiratory apnoea (t
a=0,0.5,1.0 and 2.0 s), where tidal volume, breathing frequency, inspiratory and expiratory flow patterns were kept constant. We determined the alveolar ventilations (V
) of He and SF6 from the product of end-expiratory lung volume (V
L,E) and specific ventilation (V
/VL,E). VL,E was determined by the dilution technique and the specific ventilations of the two gases were obtained from their multiple-breath washout. Further, tracer amounts of acetone, ether and enflurane were infused continuously into a peripheral vein and a bolus of a gas mixture of krypton, Freon12 and SF6 was introduced into the peritoneal cavity. We determined the Excretion (E) and Retention (R) of these six gases according to the multiple-inert-gas-elimination technique (MIGET). V
A increased with increasing t
a, where V
A,He was about 14% larger than V
A,SF6 For both gases, however, the increase in V
A relative to control (V
A for t
a=0) was virtually the same: 9, 11 and 19% (mean values) for t
a=0.5, 1.0 and 2.0 s respectively. For all dogs the E/R curve shifted to larger E values with increasing ta. E for the most soluble tracer gas (acetone) increased by 11, 21 and 25% for ta=0.5, 1.0 and 2.0 s respectively. V
A, determined with MIGET from the ventilation/perfusion distribution, increased by almost the same percentages. These results are interpreted to indicate that pulmonary gas exchange is substantially impaired by incomplete intra-acinar gas mixing. 相似文献
16.
F. M. Faraci J. P. Kiley M. R. Fedde 《Pflügers Archiv : European journal of physiology》1984,402(2):162-165
To determine if arterial chemoreceptors contribute to the ventilatory response during exercise, we measured minute ventilation (
1) in spontaneously breathing Pekin ducks (Anas platyrhynchos) during rest and running exercise when the inspired gas was switched from either 21% or 12% O2 to 100% O2 for 45 s (O2-test). In normoxia at rest (PaO2=99 Torr), inhaling 100% O2 reduced
1 by 30%, while during resting hypoxic conditions, (PaO2=56 Torr), 100% O2 inhalation reduced
1 by 66%. During exercise, abruptly inhaling 100% O2 decreased
1 by only 14% and 33% in normoxic and hypoxic conditions, respectively. Thus, only a small fraction of the ventilatory response during exercise under normoxic conditions is due to an arterial chemoreceptor input. However, during exercise in hypoxic conditions, arterial chemoreceptors provide a substantial portion of the total drive to ventilation. 相似文献
17.
The effect of power output increment, based on an increase in pedal rate, on blood lactate accumulation during graded exercise is unknown. Therefore, in the present study, we examined the effect of two different rates of power output increments employing two pedal rates on pulmonary ventilation and blood lactate responses during graded cycle ergometry in young men. Males (n=8) with an mean (SD) peak oxygen uptake of 4.2 (0.1) 1·min–1 served as subjects. Each subject performed two graded cycle ergometer tests. The first test, conducted at 60 rev· min–1, employed 4 min of unloaded pedaling followed by a standard power output step increment (SI) of 60 W every 3rd min. The second test, conducted at 90 rev·min–1, employed 4 min of unloaded pedaling followed by a high power output step increment (HI) of 90 W every 3rd min. Venous blood was sampled from a forearm vein after 5 min of seated rest, 4 min of unloaded pedaling, and every 3rd min of graded exercise. Peak exercise values for heart rate, oxygen uptake (
O2), and ventilation (
E) were similar (P > 0.05) for SI and HI exercise, as was the relationship between
E and
O2, and between
E and carbon dioxide production (
CO2). However, the relationship between blood lactate concentration and
O2 was dissimilar between SI and HI exercise with blood lactate accumulation beyond the lowest ventilatory equivalent of oxygen, and peak exercise blood lactate concentration values significantly higher (P < 0.05) for SI [12.8 (2.6) mmol·l–1] compared to HI [8.0(1.9) mmol·l–1] exercise. Our findings demonstrate that blood lactate accumulation and
E during graded exercise are dissociated. Blood lactate accumulation is influenced by the rate of external power output increment, while
E is related to
O2 and
CO2. 相似文献
18.
Syuzo Kumagai Kiyoji Tanaka Yoshiyuki Matsuura Akira Matsuzaka Kohji Hirakoba Katsumi Asano 《European journal of applied physiology》1982,49(1):13-23
Summary The purpose of present study was to assess the relationship between anaerobic threshold (AT) and performances in three different distance races (i.e., 5 km, 10 km, and 10 mile). AT,
O2 max, and related parameters for 17 young endurance runners aged 16–18 years tested on a treadmill with a discontinuous method. The determination of AT was based upon both gas exchange and blood lactate methods. Performances in the distance races were measured within nearly the same month as the time of experiment. Mean AT-
O2 was 51.0 ml·kg–1·min–1 (2.837 l·min–1), while
O2 max averaged 64.1 ml·kg–1·min–1 (3.568 l·min–1). AT-HR and %AT (AT-
O2/
O2 max) were 174.7 beats·min–1 and 79.6%, respectively. The correlations between
O2 max (ml·kg–1·min–1) and performances in the three distance races were not high (r=–0.645, r=–0.674, r=–0.574), while those between AT-
O2 and performances was r=–0.945, r=–0.839, and r=–0.835, respectively. The latter results indicate that AT-
O2 alone would account for 83.9%, 70.4%, and 69.7% of the variance in the 5 km, 10 km, and 10 mile performances, respectively. Since r=–0.945 (5 km versus AT-
O2) is significantly different from r=–0.645 (5 km versus
O2 max), the 5 km performance appears to be more related to AT-
O2 than VO2 max. It is concluded that individual variance in the middle and long distance races (particularly the 5 km race) is better accounted for by the variance in AT-
O2 expressed as milliliters of oxygen per kilogram of body weight than by differences in
O2 max. 相似文献
19.
Dr. J. Böswart I. Kuta Z. Lisý P. Kostiuk 《European journal of applied physiology》1980,43(3):193-199
Summary The effect of physical exercise on erythrocyte 2,3-diphosphoglycerate (2,3-DPG) content was studied in eight trained speed canoeists aged 15–25 years. One-stage 4-min load on a paddling ergometer corresponding to a 1 km race was observed. During the test, the following cardiorespiratory parameters were recorded:
. Blood lactate level and haematocrit were also determined. The average resting values of 2,3-DPG and haematocrit were statistically significant increased.After 6 month intense training there was a significant increase in 2,3-DPG, and the other parameters were also increased.Abbreviations 2,3-DPG
2,3-diphosphoglycerate
- Hc
haematocrite
-
pulmonary ventilation
-
oxygen uptake
-
oxygen uptake per one kg of body weight
- HR
heart rate
-
pulse oxygen
- R
respiratory quotient
- La
lactate
- ¯x
arithmetical mean
- SD
standard deviation
-
t
value of t-test for paired comparisons 相似文献
20.
Nariko Takano Akemi Sakai Yasuko Iida 《Pflügers Archiv : European journal of physiology》1981,390(1):56-62
We attempted to analyze how
is regulated during progesterone-induced hyperventilation in the luteal phase. A model for the CO2 control loop was constructed, in which the function of the CO2 exchange system was described as
and that of the CO2 sensing system as
. Using this model, we estimated (1) the primary increase in
produced by progesterone stimulation and (2) the effectiveness (E) of the loop to regulateP
A
CO
2, defined as P
A
CO
2 (op)/P
A
CO
2 (cl) in which op signifies open-loop and cl, closed-loop. These respiratory variables were investigated throughout the menstrual cycle in 8 healthy women. During the luteal phase, on average,
increased by 9.4% andP
A
CO
2,B andH decreased by 0.33 kPa (2.5 mm Hg), 0.47 kPa (3.5 mm Hg) and 13.6%, respectively, whileS and
did not change significantly.
(op) increased progressively on successive days of the luteal phase whileE remained unchanged at a value of 7.9, thus there was a progressive decrease inP
A
CO
2. The decrease inH was considered to lessen P
A
CO
2 (op) and so reduce the final deviation ofP
A
CO
2 (P
A
CO
2 (cl)) during the luteal phase. The decrease inB was found to be dependent on
(op). 相似文献