High-altitude adaptation and maximum work performance

1984 ◽  
Vol 246 (4) ◽  
pp. R619-R623
Author(s):  
E. S. Johnson ◽  
C. A. Finch
Keyword(s):  
Beneficial Effect ◽  
High Altitude ◽  
Sea Level ◽  
Carrying Capacity ◽  
Work Performance ◽  
Work Capacity ◽  
Hypobaric Chamber ◽  
Altitude Adaptation ◽  
Maximum Work ◽  
Positive Effect

The treadmill work performance of rats at sea level with normal or elevated hematocrits was compared with that of rats conditioned in a hypobaric chamber at 450 Torr for 3 wk with similar hematocrit adjustments. A mean increase in hematocrit to 62 significantly improved the work performance of rats at sea level and at ambient O2 tensions of 100, 75, and 35 Torr. By contrast, rats conditioned in a hypobaric chamber with mean hematocrits of 40 and 58 performed similarly at all O2 tensions compared with sea-level rats with hematocrits of 43. Thus, although an increase in O2-carrying capacity of the blood of sea-level animals increased work capacity, altitude adaptation did not appear to result in any positive effect on work capacity, and indeed, seemed to interfere with the beneficial effect of polycythemia on maximum work performance.

Myoglobin content and enzymatic activity of muscle and altitude adaptation

1962 ◽  
Vol 17 (2) ◽  
pp. 301-305 ◽  
Author(s):  
Baltazar Reynafarje
Keyword(s):  
Cytochrome C ◽  
Enzymatic Activity ◽  
High Altitude ◽  
Sea Level ◽  
Human Subjects ◽  
Reduced Form ◽  
Sartorius Muscle ◽  
Healthy Human ◽  
Altitude Adaptation ◽  
Made In

Quantitative determinations of myoglobin were made in the sartorius muscle of healthy human subjects native to sea level and high altitude. The specific activities of the reduced form of diphosphopyridine nucleotide oxidase (DPNH-oxidase), DPNH- and the reduced form of triphosphopyridine nucleotide (TPNH)-cytochrome c reductases, transhydrogenase, and isocitric and lactic dehydrogenases were also examined. There was found a significantly higher myoglobin concentration in the muscle of the high-altitude native as compared with the sea-level resident. The enzyme systems DPNH-oxidase, TPNH-cytochrome c reductase, and transhydrogenase similarly showed a significantly higher activity in the altitude resident. It was concluded that the respiratory capacity of the muscle was apparently higher in the altitude native than in the sea-level one. The enhanced enzymatic activity was probably related to the higher pigment content of the skeletal muscle. Results on myoglobin determinations in several other muscles from certain sea-level patients are discussed. Submitted on July 24, 1961

Effects of erythrocyte infusion on VO2max at high altitude

1996 ◽  
Vol 81 (1) ◽  
pp. 252-259 ◽  
Author(s):  
A. J. Young ◽  
M. N. Sawka ◽  
S. R. Muza ◽  
R. Boushel ◽  
T. Lyons ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Carrying Capacity ◽  
Hemoglobin Concentration ◽  
Treadmill Running ◽  
Control Group ◽  
O2 Uptake ◽  
Control Subjects ◽  
And Control ◽  
Experimental Group

This study investigated whether autologous erythrocyte infusion would ameliorate the decrement in maximal O2 uptake (VO2max) experienced by lowlanders when they ascend to high altitude. VO2max was measured in 16 men (treadmill running) at sea level (SL) and on the 1st (HA1) and 9th (HA9) days of high-altitude (4,300 m) residence. After VO2max was measured at SL, subjects were divided into two matched groups (n = 8). Twenty-four hours before ascent to high altitude, the experimental group received a 700-ml infusion of autologous erythrocytes and saline (42% hematocrit), whereas the control group received only saline. The VO2max of erythrocyte-infused [54 +/- 1 (SE) ml.kg-1.min-1] and control subjects (52 +/- 2 ml.kg-1.min-1) did not differ at SL before infusion. The decrement in VO2max on HA1 did not differ between groups, averaging 26% overall, despite higher (P < 0.01) arterial hematocrit, hemoglobin concentration, and arterial O2 content in the erythrocyte-infused subjects. By HA9, there were no longer any differences in hematocrit, hemoglobin concentration, or arterial O2 content between groups. No change in VO2max occurred between HA1 and HA9 for either group. Thus, despite increasing arterial O2-carrying capacity, autologous erythrocyte infusion did not ameliorate the decrement in VO2max at 4,300-m altitude.

High-altitude training does not increase maximal oxygen uptake or work capacity at sea level in rowers

2007 ◽  
Vol 3 (4) ◽  
pp. 256-262 ◽  
Author(s):  
K. Jensen ◽  
T. S. Nielsen ◽  
A. Fiskestrand ◽  
J. O. Lund ◽  
N. J. Christensen ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
High Altitude ◽  
Sea Level ◽  
Maximal Oxygen Uptake ◽  
Work Capacity ◽  
Altitude Training

scholarly journals High-altitude exposure of three weeks duration increases lung diffusing capacity in humans

2011 ◽  
Vol 110 (6) ◽  
pp. 1564-1571 ◽  
Author(s):  
Piergiuseppe Agostoni ◽  
Erik R. Swenson ◽  
Maurizio Bussotti ◽  
Miriam Revera ◽  
Paolo Meriggi ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Diffusing Capacity ◽  
Membrane Diffusion ◽  
Alveolar Volume ◽  
Pulmonary Capillary ◽  
Capillary Blood Volume ◽  
Pulmonary Capillary Blood ◽  
Altitude Adaptation ◽  
Alveolar Capillary

Background: high-altitude adaptation leads to progressive increase in arterial PaO2. In addition to increased ventilation, better arterial oxygenation may reflect improvements in lung gas exchange. Previous investigations reveal alterations at the alveolar-capillary barrier indicative of decreased resistance to gas exchange with prolonged hypoxia adaptation, but how quickly this occurs is unknown. Carbon monoxide lung diffusing capacity and its major determinants, hemoglobin, alveolar volume, pulmonary capillary blood volume, and alveolar-capillary membrane diffusion, have never been examined with early high-altitude adaptation. Methods and Results: lung diffusion was measured in 33 healthy lowlanders at sea level (Milan, Italy) and at Mount Everest South Base Camp (5,400 m) after a 9-day trek and 2-wk residence at 5,400 m. Measurements were adjusted for hemoglobin and inspired oxygen. Subjects with mountain sickness were excluded. After 2 wk at 5,400 m, hemoglobin oxygen saturation increased from 77.2 ± 6.0 to 85.3 ± 3.6%. Compared with sea level, there were increases in hemoglobin, lung diffusing capacity, membrane diffusion, and alveolar volume from 14.2 ± 1.2 to 17.2 ± 1.8 g/dl ( P < 0.01), from 23.6 ± 4.4 to 25.1 ± 5.3 ml·min−1·mmHg−1 ( P < 0.0303), 63 ± 34 to 102 ± 65 ml·min−1·mmHg−1 ( P < 0.01), and 5.6 ± 1.0 to 6.3 ± 1.1 liters ( P < 0.01), respectively. Pulmonary capillary blood volume was unchanged. Membrane diffusion normalized for alveolar volume was 10.9 ± 5.2 at sea level rising to 16.0 ± 9.2 ml·min−1·mmHg−1·l−1 ( P < 0.01) at 5,400 m. Conclusions: at high altitude, lung diffusing capacity improves with acclimatization due to increases of hemoglobin, alveolar volume, and membrane diffusion. Reduction in alveolar-capillary barrier resistance is possibly mediated by an increase of sympathetic tone and can develop in 3 wk.

scholarly journals Work tolerance: age and altitude

1964 ◽  
Vol 19 (3) ◽  
pp. 483-488 ◽  
Author(s):  
D. B. Dill ◽  
S. Robinson ◽  
B. Balke ◽  
J. L. Newton
Keyword(s):  
Heart Rate ◽  
High Altitude ◽  
Sea Level ◽  
Barometric Pressure ◽  
Work Capacity ◽  
Bicycle Ergometer ◽  
Oxygen Intake ◽  
High Altitudes ◽  
Maximum Capacity ◽  
Adaptation To Altitude

The work capacity at sea level and high altitude has been measured on nine men, five of whom had taken part in similar studies at high altitudes from 18 to 33 years earlier. Except for a few measurements on the treadmill at sea level each subject rode the bicycle ergometer; the brakeload was increased minute-by-minute until his limit was reached. The maximum capacity for oxygen intake declined with age both at high altitude and at sea level. Individual responses varied greatly: the most fit individual, age 54, had about as great an oxygen intake on the ergometer at Pb 455 mm Hg as had a man one-half his age at sea level. After 5 or 6 weeks of acclimatization a man of 71 attained at Pb 485 a greater oxygen intake per minute and per kilogram than that of a man of 27. At that barometric pressure the limiting oxygen intake on the bicycle ergometer may be only one-half of the sea-level value 2 or 3 days after arrival; after 4–6 weeks it may range from two-thirds to five-sixths of the sea-level value. adaptation to altitude; altitude and heart rate; altitude and maximum O2 intake; altitude and respiratory volume Submitted on November 4, 1963

Effects of High Altitude on Performance of Three Different Types of Work

1967 ◽  
Vol 25 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Wayne O. Evans ◽  
C. Frank Consolazio
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Work Performance ◽  
Dynamic Strength ◽  
Bicycle Ergometer ◽  
Gradual Transition ◽  
Physical Conditioning ◽  
Explosive Strength ◽  
Daily Exercise ◽  
Low Altitude

To determine the effects of transition from a low altitude to a high altitude on three types of work performance, the rate at which S proceeded from low to high altitude, and the effects of a physical conditioning program. 24 young soldiers were studied at sea level. Their maximum performance on medicine ball putting (an explosive strength task), the bicycle ergometer (a stamina task), and chin-ups (a dynamic strength task) were measured. Half of the Ss participated in a physical conditioning program; Ss daily exercise was based upon exercise at 90% of his own maximum capacity. Eight Ss remained at sea level, 8 Ss ascended to an altitude of 14,110 ft. gradually (1 wk. each at an altitude of 5,200 ft. and 11,400 ft.), 8 Ss went directly to 14,110 ft. within 1 day. It was not possible to predict the amount of depression of performance capacity found at high altitude. Dynamic strength was not affected by high altitude, but explosive strength and stamina were. Explosive strength readapted within 2 wk.; stamina had not readapted after 1 mo. Gradual transition to high altitude was beneficial for the explosive strength but did not effect stamina. Physical conditioning proved efficacious in reducing performance decrement in explosive strength and stamina.

PENGARUH PELATIHAN DAN KOMPETENSI TERHADAP KINERJA KARYAWAN MELALUI MOTIVASI PADA PT. CIPTA KRIDA BAHARI JAKARTA DAN SUMATERA AREA

2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Freddrick Tiagita Putra Baeha Waruwu, SE., MM.
Keyword(s):  
Empirical Evidence ◽  
Indirect Effects ◽  
Work Performance ◽  
Training Programs ◽  
Employee Performance ◽  
Descriptive Analysis ◽  
Employee Motivation ◽  
Direct And Indirect Effects ◽  
Dependent Variables ◽  
Positive Effect

The purpose of this study was to test and obtain empirical evidence about the direct and indirect effects of training and competence together to employees performance in PT. Cipta Krida Bahari. This study uses an explanatory approach Analysis and Descriptive Analysis, which aims to determine the effect of independent and dependent variables. Furthermore, the present invention will be described, by observation and research and describe the nature or the events ongoing at the time of the study and examine the causes of the symptoms. In this study examines the influence of variables of training, competence and motivation, simultaneously or partially on employee performance. The benefits of this research is that companies in improving the performance of employees through training programs, attention to improving the competence of employees, increase employee motivation, and in turn can help in improving the work (performance) of each individual employee. The results showed simultaneously and partially variable training and competency positive effect on employee motivation and improve employee performance

DO REALLY EMOTIONAL QUOTIENT AND SPIRITUAL QUOTIENT AFFECT ON EMPLOYEE PERFORMANCE?

2017 ◽  
Vol 1 (1) ◽  
pp. 33-37
Author(s):  
Shofia Amin ◽  
Nany Mawaddah
Keyword(s):  
Emotional Intelligence ◽  
Statistical Analysis ◽  
Least Squares ◽  
Work Performance ◽  
Employee Performance ◽  
Spiritual Intelligence ◽  
Path Modeling ◽  
Emotional Quotient ◽  
High Level ◽  
Positive Effect

The main purpose of this study is to examine the effect of emotional quotient on work performance, and the effect of spiritual quotient on work performance at BPMPPT of Jambi City. Using 68 employees as respondent, the data were collected by distributing questionnaire and analyzed by using partial least squares path modeling (PLS-SEM). The results of the analysis show that overall emotional intelligence and spiritual intelligence employee BPMPPT Jambi city is at a high level of quotient. While employee performance BPMPPT Jambi city is at a level of performance was enough. The statistical analysis shows that partially and simultantly emotional quotient and spiritual quotient has significant and positive effect on employee performance. Keywords: Emotional Quotient, Spiritual Quotient, Performance

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