Oxygen uptake, acid-base status, and performance with varied inspired oxygen fractions

1980 ◽  
Vol 49 (5) ◽  
pp. 863-868 ◽  
Author(s):  
R. P. Adams ◽  
H. G. Welch
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Bicycle Ergometer ◽  
Carbon Dioxide Tension ◽  
Limiting Factor ◽  
Vo2 Max ◽  
And Performance ◽  
Lactate Levels ◽  
Performance Times ◽  
Inspired Oxygen

Six subjects rode a bicycle ergometer on three occasions breathing 17, 21, or 60% oxygen. In addition to rest and recovery periods, each subject worked for 10 min at 55% of maximal oxygen uptake (VO2 max) and then to exhaustion at approximately 90% VO2 max. Performance time, inspired and expired gas fractions, ventilation, and arterialized venous oxygen tension (PO2), carbon dioxide tension (PCO2), lactate, and pH were measured. VO2, carbon dioxide output, [H+]a, and [HCO3-]a were calculated. Performance times were longer in hyperoxia than in normoxia or hypoxia. However, VO2 was not different at exhaustion in normoxia compared with hypoxia or hyperoxia. During exercise, hypoxia was associated with increased lactate levels and decreased [H+]a, PCO2, and [HCO3-]a. The opposite trends were generally associated with hyperoxia. At exhaustion, [H+]a was not different under any inspired oxygen fraction. These results support the contention that oxygen is not limiting for exercise of this intensity and duration. The results also suggest that [H+] is a possible limiting factor and that the effect of oxygen on performance is perhaps related to control of [H+].

Breathing in brief exercise

1960 ◽  
Vol 15 (4) ◽  
pp. 583-588 ◽  
Author(s):  
F. N. Craig ◽  
E. G. Cummings
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Metabolic Cost ◽  
Carbon Dioxide Tension ◽  
Minute Volume ◽  
Carbon Dioxide Output ◽  
Respiratory Minute Volume ◽  
Before And After

Two men ran for 20 or 60 seconds while inhaling air, oxygen or 4% carbon dioxide. Inspired respiratory minute volume was determined for each breath. Ventilation increased suddenly in the first breath with minimal changes in end-expiratory carbon dioxide tension and respiratory exchange ratio to a rate that remained constant for 20 seconds before increasing further. The rate of carbon dioxide output was uniform during the first 20 seconds. A 12% grade did not increase ventilation or oxygen uptake during runs of 20 seconds, but in the first minute of recovery, ventilation was 64% greater than after level runs. Inhalation of oxygen inhibited ventilation by 24% in the 20-second periods before and after the end of a 60-second run. Inhalation of carbon dioxide begun at rest produced increments in ventilation and end-expiratory carbon dioxide tension that varied little during running and recovery. In the 20-second runs ventilation varied with speed but appeared independent of ultimate metabolic cost. Submitted on January 21, 1960

Use of respiratory quotients in assessment of aerobic work capacity

1962 ◽  
Vol 17 (1) ◽  
pp. 47-50 ◽  
Author(s):  
B. Issekutz ◽  
N. C. Birkhead ◽  
K. Rodahl
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Work Load ◽  
Work Capacity ◽  
Bicycle Ergometer ◽  
Carbon Dioxide Output ◽  
Ergometer Test ◽  
Aerobic Work Capacity ◽  
Bicycle Ergometer Test ◽  
Better Than

Oxygen uptake and carbon dioxide output were measured in 32 untrained subjects during exercise on the bicycle ergometer. It was shown that the work respiratory quotient (RQ) under standardized conditions can be used as a measure of physical fitness. ΔRQ (work RQ minus 0.75) increases logarithmically with the work load and maximal O2 uptake is reached at a ΔRQ value of 0.40. This observation offered the possibility of predicting the maximal O2 uptake of a person, based on the measurement of RQ during a single bicycle ergometer test at a submaximal load. For each work RQ between 0.95 and 1.15 a factor was presented, together with the aid of a simple equation, which gave a good approximation (generally better than ±10%) of the maximal O2 uptake.

Tissue carbon dioxide stores: magnitude of acute change in the dog

1964 ◽  
Vol 206 (4) ◽  
pp. 887-890 ◽  
Author(s):  
S. F. Sullivan ◽  
R. W. Patterson ◽  
E. M. Papper
Keyword(s):  
Carbon Dioxide ◽  
Steady State ◽  
Dissociation Constant ◽  
Average Rate ◽  
Carbon Dioxide Tension ◽  
Whole Body ◽  
Limiting Factor ◽  
Acute Change ◽  
Washout Curves ◽  
Mixed Venous

Carbon dioxide washout curves were determined in hyperventilated dogs. Direct measurement of mixed venous carbon dioxide tension allowed calculation of changes in whole-body CO2 stores. The average whole-body CO2 dissociation constant in ten studies was 3.73 ml/kg mm. The limiting factor in reaching a new steady-state value was represented by a slow compartment in the washout curve. The average rate constant for this compartment was 0.062 min–1. The slowest compartment in this analysis has a 98% change in 1 hr, therefore the experimentally determined whole-body dissociation constant should closely approximate actual changes in tissue CO2 stores, excluding bone and fat.

Mean myoglobin oxygen tension during exercise at maximal oxygen uptake

1975 ◽  
Vol 39 (1) ◽  
pp. 135-144 ◽  
Author(s):  
B. J. Clark ◽  
R. F. Coburn
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Uptake ◽  
Aerobic Capacity ◽  
Maximal Oxygen Uptake ◽  
Bicycle Ergometer ◽  
Limiting Factors ◽  
Considerable Variability ◽  
Vo2 Max ◽  
The Subject ◽  
Total Body

Changes in intracellular Po2 in myoglobin containing skeletal muscle during exercise were estimated in normal nonathlete subjects from measurements of shifts of CO between blood and muscle under conditions where the total body CO stores remained constant. Exercise was performed on a bicycle ergometer. In 1.5–2 and 6–7 min runs at Vo2 max with the subject breathing 21% O2, mean MbCO/HbCO increased 146 +/- 7 and 163 +/- 11% of resting values, respectively (P less than 0.05). With the subjects breathing 13–14% O2, in 1.5–2 and 6–7 min runs, Vo2 max fell an average of 4.3 +/- 5.1% and 12.0 +/- 5.2%, respectively, and mean MbCO/HbCO increased to 233 +/- 18% and 210 +/- 52% of resting value, respectively (P less than 0.05). These findings suggest that mean myoglobin Po2 fell during exercise at Vo2 max, with the subjects breathing 21% O2 and the decrease in mean myoglobin Po2 was greater with the subject breathing 13–14% O2. There was considerable variability in different subjects and in some, the data were not consistent with intracellular O2 availability limiting aerobic metabolism. The data support a postulate that there are several limiting factors for the aerobic capacity, including intracellular O2 availability.

scholarly journals PO-136 Cycling Incremental test using Breath-by-breath Metabolic Cart to Predict VO2 max

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Fei Wang ◽  
Haixia Fu
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Functional Data ◽  
Maximum Oxygen Consumption ◽  
Maximum Heart Rate ◽  
Vo2 Max ◽  
Incremental Test ◽  
Metabolic Cart

Objective Maximal oxygen uptake (VO2 max) is a key indicator to assess health as well as sports performance. In heterogeneous, athletic populations, VO2 max is one of the most frequently measured variables in exercise physiology laboratories. The purpose of this study was to investigate the relationship between Maximal oxygen uptake with other metabolism parameters during one high-intensity activity, and provide simple solution for VO2 max prediction. Methods A total of 27 young athletes were selected. The incremental test was performed on a cycle ergometer (Monark 874 E, Sweden). Participants warmed up for 5 min at 50 watts (W); thereafter, the power output was increased 125 W every 3 min until exhaustion, which was defined as the incapacity to maintain a pedal cadence above 60 revolution per minute (rpm). Oxygen uptake (V̇O2), carbon dioxide production (V̇CO2) and other metabolism indexes were obtained breath-by-breath throughout the test using a metabolic cart (Quark b2, COSMED, Italy). Heart rate (HR) was measured throughout the test using a HR monitor (Polar Vantage NV, Finland). The main method in the VO2 prediction is the use of a mixed effects regression model. The potential explanatory variables include VO2kg (functional data with information on oxygen consumption per kg weight during the test), HR (functional data with heart rate information during the test), MHR (maximum heart rate of the athlete), VO2kgmean (average oxygen consumption during the test), VO2kgmax (maximum oxygen consumption value during the test), VCO2 (carbon dioxide emissions per minute during the test), HRmean (heart rate average), HRmax (maximum heart rate value during the test), age, height, weight. The model statistical analyses were implemented in R platform (version 3.3.3). Results (1) regression model results revealed MHR did not have stronger effects on VO2 max prediction. (2) Parameters of VO2kg, HR, HRmean, height, weight showed relative higher r2 values and lower RMSE values indicating the possible indexes for VO2 max prediction. (3) the interaction effects occurred between indicators which increase the complexity of the model. Conclusions In this study, a simple methodology for the prediction of maximum oxygen consumption has been presented. It combines a relatively simple level of base metabolism parameters. Despite the easy test and low level of exercise required the test provides an rational prediction of VO2 max, which could provide necessary information when it applied as a simple way. 

The effect of prior heavy exercise on the parameters of the power-duration curve for cycle ergometry

2009 ◽  
Vol 34 (6) ◽  
pp. 1001-1007 ◽  
Author(s):  
Akira Miura ◽  
Chiaki Shiragiku ◽  
Yuiko Hirotoshi ◽  
Asami Kitano ◽  
Masako Yamaoka Endo ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
High Intensity ◽  
Peak Oxygen Uptake ◽  
Bicycle Ergometer ◽  
Cycle Ergometry ◽  
Work Rate ◽  
Hyperbolic Function ◽  
Heavy Exercise ◽  
Improved Performance ◽  
Lactate Levels

The tolerable duration (t) of high-intensity cycle ergometry is well characterized by a hyperbolic function of power output (P) with an asymptote (termed the critical power (CP)) and a curvature constant (denoted W′). The purpose of this study was to investigate the effect of prior heavy exercise (W-up) that specifically engenders an acidosis on CP and W′. Eight healthy subjects performed 2 sets of 4 high-intensity square-wave exercise bouts on a bicycle ergometer to estimate CP and W′, with (W-up) and without (control) prior exercise, respectively. Exercise intensities of the 4 main bouts were selected in the range of 90% to 135% peak oxygen uptake so as to reach the limit of tolerance between approximately 1.5 and 10 min. The W-up bout was preceded by 6 min cycling at a work rate halfway between the lactate threshold and peak oxygen uptake (mean ± SD of 153.8 ± 29.8 W) starting 12 min before the main bout. Blood lactate levels ([La]b) just before the main exercise bouts in W-up conditions were significantly higher than those of the control (4.7 ± 1.1 and 1.4 ± 0.4 mEq·L–1, respectively; p < 0.05). However, there were no significant differences in end-exercise [La]b. W-up increased significantly the tolerable duration at every work rate compared with the control, which was attributable exclusively to increased CP (176.5 ± 34.3 and 168.7 ± 31.3 W, respectively; p < 0.05), without any significant change in W′ (11.0 ± 3.2 and 11.0 ± 3.1 kJ, respectively). It is concluded that the prior heavy exercise improved performance mainly because of an enhanced aerobic component of exercise energetics, as indicated by a higher CP and lower increment in the [La]b.

scholarly journals CORRELATION BETWEEN DURATION SPENT IN FITNESS CENTER AND VO2 MAX LEVEL AMONG ADULTS

2021 ◽  
Vol 1 (2) ◽  
pp. 47
Author(s):  
Mohammad Sabiq ◽  
Putri HA Rahman ◽  
Kurnia Wahyudi
Keyword(s):  
The United States ◽  
Step Test ◽  
Vo2 Max ◽  
Exercise Frequency ◽  
Cross Sectional ◽  
Fitness Center ◽  
Maximum Value ◽  
And Performance ◽  
Performance Times ◽  
Spearman’S Correlation

VO2 max or oxygen consumption maximum value is a gold standard indicator towards cardiovascular and aerobic endurance because it refers to the maximum amount of oxygen used by an individual in one minute during maximum physical activity. The study's purpose was to see the correlation between duration spent in the fitness center and VO2 max value among adults. This study used the analytical study method, cross-sectional type. We chose the participant from members of Gold’s Gym fitness center at Cihampelas, aged 18-45 years old, with 3 months minimum of activity, and exercise frequency around three times per week. Theparticipants who had cardiovascular and pulmonary disease, serious physical injury, had already exercised during the time of observation, or professionally trained athletes were excluded. We used the Queen College step test for the instrument. There were 47 participants in this study. Spearman’s correlation coefficient was calculated to measure the correlation between duration spent and VO2 max, and the result was 0.77(95% CI 0.64; 0.85), p<0.001 which is categorized as a strong correlation. From this study, we found that with the increase of duration spent in the fitness center, the VO2 max level is also increasing, and vice versa. This result is supported by a study from the United States which finds a correlation between VO2max and performance times of recreational triathletes. In conclusion, there is a positive correlation between duration spent in the fitness center and VO2 max level among adults.

Recommendations for Mechanical Ventilation during Donor Care

2000 ◽  
Vol 10 (1) ◽  
pp. 33-40 ◽  
Author(s):  
David J. Powner ◽  
Joseph M. Darby ◽  
Susan A. Stuart
Keyword(s):  
Carbon Dioxide ◽  
Mechanical Ventilation ◽  
Cardiac Output ◽  
Oxygen Uptake ◽  
Tidal Volume ◽  
Organ Procurement ◽  
Mechanical Ventilator ◽  
Positive End Expiratory Pressure ◽  
Fraction Of Inspired Oxygen ◽  
Inspired Oxygen

The organ procurement coordinator usually directs adjustments to the mechanical ventilator during donor care. It is often difficult to achieve optimal oxygen uptake and carbon dioxide removal while avoiding barotrauma or undesirable effects on the cardiac output. Interrelationships among a variety of ventilator parameters must be understood in order to achieve the desired goal of providing the best organs possible. These recommendations review the key ventilator parameters of tidal volume; positive end-expiratory pressure; auto–positive end-expiratory pressure; fraction of inspired oxygen; and flowrate and frequency and their interactions in controlling peak, plateau, and mean and end-expiratory airway pressures.

CORRELATION BETWEEN DURATION SPENT IN FITNESS CENTER AND VO2 MAX LEVEL AMONG ADULTS

2017 ◽  
Vol 1 (2) ◽  
pp. 7
Author(s):  
Mohammad Sabiq Bin Mohammad Tapsir ◽  
Putri Halleyana Adrikni Rahman ◽  
Kurnia Wahyudi
Keyword(s):  
Analytical Study ◽  
The United States ◽  
Step Test ◽  
Vo2 Max ◽  
Exercise Frequency ◽  
Cross Sectional ◽  
Fitness Center ◽  
Maximum Value ◽  
And Performance ◽  
Performance Times

VO2 max or oxygen consumption maximum value is a gold standard indicator towardscardiovascular and aerobic endurance because it refers to the maximum amount of oxygenused by an individual in one minute during maximum physical activity. The study purpose wasto see the correlation between duration spent in the fitness center and VO2 max value amongadults. This study used analytical study method, cross-sectional type. We chose the participantfrom members of Golds Gym fitness center at Cihampelas, aged 18-45 years old, with 3months minimum of activity, and exercise frequency around three times per week. Theparticipants who had the cardiovascular and pulmonary disease, serious physical injury, hadalready exercised during the time of observation, or professionally trained athletes wereexcluded. We used Queen College step test for the instrument. There were 47 participants inthis study. Spearmans correlation coefficient was calculated to measure the correlationbetween duration spent and VO2 max, and the result was 0.77(95% CI 0.64; 0.85), p<0.001which is categorized as strong correlation. From this study, we found that with the increase ofduration spent in the fitness center, the VO2 max level is also increasing, and vice versa. Thisresult is supported by a study from the United States which finds a correlation between VO2max and performance times of recreational triathletes. In conclusion, there is a positivecorrelation between duration spent in the fitness center and VO2 max level among adults.

The time Course During 36 Weeks’ Endurance Training of Changes in o2 max. and Anaerobic Threshold as Determined with a new Computerized Method

1984 ◽  
Vol 67 (2) ◽  
pp. 229-236 ◽  
Author(s):  
D. A. Smith ◽  
T. V. O'Donnell
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Endurance Training ◽  
Anaerobic Threshold ◽  
Time Course ◽  
Minute Ventilation ◽  
Vo2 Max ◽  
Cardiac Frequency ◽  
Ventilatory Equivalent ◽  
End Tidal

1. Six healthy male subjects followed a programme of endurance training for 36 weeks. At 12 week intervals each underwent an incremental exercise test to maximum on a treadmill. Minute ventilation, cardiac frequency, expired and end-tidal concentrations of oxygen and carbon dioxide, oxygen uptake and carbon dioxide output were measured continuously during each test. 2. Anaerobic threshold (AT) was determined non-invasively as the onset of sustained increases in each of the ventilatory equivalent for oxygen, expired and end-tidal concentrations of oxygen followed by an increase in ventilatory equivalent for carbon dioxide after a brief delay due to isocapnic buffering. A new computerized cumulative-sum method was employed. 3. Significant increases in maximum oxygen uptake (Vo2 max.) of 13.6%, AT (32.3%) and % AT/Vo2 max. (17.0%) and a significant decrease (10.2%) in cardiac frequency at an oxygen uptake of 1.0 litres/min (fc1.0) were observed at the completion of the training programme. 4. The time courses of the changes for each of AT, Vo2 max. and fc1.0 were not identical during the training. Compared with Vo2 max. the disproportionate increases in AT occurred earlier and were usually completed within 12 weeks. Vo2 max. increased for the first 24 weeks of training, but showed no further increase over the final 12 weeks. fc1.0 decreased through the whole training period. 5. The improved AT after training is more likely to be related to improved peripheral utilization of oxygen than to an improved oxygen delivery to muscles.

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