scholarly journals Prolonged Sojourn at Very High Altitude Decreases Sea-Level Anaerobic Performance, Anaerobic Threshold, and Fat Mass

2021 ◽  
Vol 12 ◽  
Author(s):  
Robert K. Szymczak ◽  
Tomasz Grzywacz ◽  
Ewa Ziemann ◽  
Magdalena Sawicka ◽  
Radosław Laskowski
Keyword(s):  
Body Weight ◽  
High Altitude ◽  
Sea Level ◽  
Fat Mass ◽  
Anaerobic Threshold ◽  
Aerobic Power ◽  
Hematological Parameters ◽  
Maximal Aerobic Power ◽  
Anaerobic Performance ◽  
Very High

Background: The influence of high altitude on an organism’s physiology depends on the length and the level of hypoxic exposure it experiences. This study aimed to determine the effect of a prolonged sojourn at very high altitudes (above 3,500m) on subsequent sea-level physical performance, body weight, body composition, and hematological parameters.Materials and Methods: Ten alpinists, nine males and one female, with a mean age of 27±4years, participated in the study. All had been on mountaineering expeditions to 7,000m peaks, where they spent 30±1days above 3,500m with their average sojourn at 4,900±60m. Their aerobic and anaerobic performance, body weight, body composition, and hematological parameters were examined at an altitude of 100m within 7days before the expeditions and 7days after they descended below 3,500m.Results: We found a significant (p<0.01) decrease in maximal anaerobic power (MAPWAnT) from 9.9±1.3 to 9.2±1.3W·kg−1, total anaerobic work from 248.1±23.8 to 228.1±20.1J·kg−1, anaerobic threshold from 39.3±8.0 to 27.8±5.6 mlO2·kg−1·min−1, body fat mass from 14.0±3.1 to 11.5±3.3%, and a significant increase (p<0.05) in maximal tidal volume from 3.2 [3.0–3.2] to 3.5 [3.3–3.9] L after their sojourn at very high attitude. We found no significant changes in maximal aerobic power, maximal oxygen uptake, body weight, fat-free mass, total body water, hemoglobin, and hematocrit.Conclusion: A month-long exposure to very high altitude led to impaired sea-level anaerobic performance and anaerobic threshold, increased maximal tidal volume, and depleted body fat mass, but had no effect on maximal aerobic power, maximal oxygen uptake, or hemoglobin and hematocrit levels.

Fractional Utilization of Maximal Aerobic Capacity in Children 6 to 8 Years of Age

1989 ◽  
Vol 1 (3) ◽  
pp. 271-277 ◽  
Author(s):  
Gary S. Krahenbuhl ◽  
Robert P. Pangrazi ◽  
William J. Stone ◽  
Don W. Morgan ◽  
Tracy Williams
Keyword(s):  
Body Weight ◽  
Aerobic Power ◽  
Cross Sectional Study ◽  
Open Circuit ◽  
Maximal Aerobic Power ◽  
Percentage Increase ◽  
Sectional Study ◽  
Maximal Aerobic Capacity ◽  
Cross Sectional ◽  
The Absolute

Untrained 6- to 8-year-old children (N = 80) served as subjects in a cross sectional study of the fractional utilization of maximal aerobic power during submaximal running. Using the open-circuit method, the absolute oxygen demands of submaximal running were found to increase with age. When expressed relative to body weight, oxygen demands of submaximal running showed no statistically significant changes over the 3-year span. VO2max increased 36.2%, which was proportionally greater than the percentage increase for either body weight (28.4%) or the absolute oxygen demands of submaximal running (22.9%). Thus, during the span of years studied there was a significant reduction in the fractional utilization of maximal aerobic power required to run at a fixed submaximal speed.

Intestinal carbohydrate absorption and permeability at high altitude (5,730 m)

1994 ◽  
Vol 76 (5) ◽  
pp. 1903-1907 ◽  
Author(s):  
A. J. Dinmore ◽  
J. S. Edwards ◽  
I. S. Menzies ◽  
S. P. Travis
Keyword(s):  
Body Weight ◽  
High Altitude ◽  
Sea Level ◽  
Intestinal Permeability ◽  
Intestinal Function ◽  
Carbohydrate Absorption ◽  
Dietary Records ◽  
The Uk ◽  
Glucose Excretion ◽  
Paired T Test

To investigate the effects of high altitude on intestinal function, the absorption and permeation of nonmetabolizable carbohydrates were measured in 14 volunteers (median age 21 yr, range 19–37 yr) at sea level in Oxford, UK; at 1,050 m in Nepal; at 5,570 m after 5 days at > 5,500 m; and at 5,730 m after 11 days at > 5,500 m. Body weight decreased 5.7 +/- 1.19 kg from sea level to 5,570 m (P < 0.001 by paired t test) despite 72-h dietary records showing no change in energy intake. Absorption of carbohydrates by mediated transport was measured by urinary xylose and 3-O-methyl-D-glucose excretion. Xylose excretion (%oral dose) decreased from 31.4 +/- 4.5% to 20.7 +/- 4.5% (P < 0.001) and 3-O-methyl-D-glucose excretion decreased from 39.7 +/- 6.1 to 33.7 +/- 7.0% (P = 0.003) from sea level to 5,730 m. Monosaccharide permeation measured by L-rhamnose excretion decreased from 11.3 +/- 2.5 to 6.2 +/- 2.0% (P = 0.001). Intestinal permeability, a measure of barrier function (ratio of lactulose to L-rhamnose), increased from 0.036 +/- 0.014 at sea level to 0.084 +/- 0.042 at 1,050 m (P = 0.006), possibly due to infective enteropathy after arrival in Nepal, but reverted to normal (0.045 +/- 0.013; P = 0.062) at 5,730 m. Absorption of all carbohydrates returned to normal after return to the UK. This study showed that a decrease in mediated (D-xylose or 3-O-methyl-D-glucose) and diffusional (L-rhamnose) monosaccharide absorption occurs at high altitude but that intestinal permeability at 5,730 m is unchanged.

Skeletal muscle changes after endurance training at high altitude

1991 ◽  
Vol 71 (6) ◽  
pp. 2114-2121 ◽  
Author(s):  
A. X. Bigard ◽  
A. Brunet ◽  
C. Y. Guezennec ◽  
H. Monod
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Lactate Dehydrogenase ◽  
High Altitude ◽  
Endurance Training ◽  
Sea Level ◽  
Dehydrogenase Activity ◽  
Altitude Training ◽  
Lactate Dehydrogenase Activity ◽  
Simulated High Altitude

The effects of endurance training on the skeletal muscle of rats have been studied at sea level and simulated high altitude (4,000 m). Male Wistar rats were randomly assigned to one of four groups: exercise at sea level, exercise at simulated high altitude, sedentary at sea level, and sedentary at high altitude (n = 8 in each group). Training consisted of swimming for 1 h/day in water at 36 degrees C for 14 wk. Training and exposure to a high-altitude environment produced a decrease in body weight (P less than 0.001). There was a significant linear correlation between muscle mass and body weight in the animals of all groups (r = 0.89, P less than 0.001). High-altitude training enhanced the percentage of type IIa fibers in the extensor digitorum longus muscle (EDL, P less than 0.05) and deep portions of the plantaris muscle (dPLA, P less than 0.01). High-altitude training also increased the percentage of type IIab fibers in fast-twitch muscles. These muscles showed marked metabolic adaptations: training increased the activity levels of enzymes involved in the citric acid cycle (citrate synthase, CS) and the beta-oxidation of fatty acids (3 hydroxyacyl CoA dehydrogenase, HAD). This increase occurred mainly at high altitude (36 and 31% for HAD in EDL and PLA muscles; 24 and 31% for CS in EDL and PLA muscles). Training increased the activity of enzymes involved in glucose phosphorylation (hexokinase). High-altitude training decreased lactate dehydrogenase activity. Endurance training performed at high altitude and sea level increased the isozyme 1-to-total lactate dehydrogenase activity ratio to the same extent.(ABSTRACT TRUNCATED AT 250 WORDS)

Living at high altitude in combination with sea-level sprint training increases hematological parameters but does not improve performance in rats

2010 ◽  
Vol 111 (6) ◽  
pp. 1147-1156 ◽  
Author(s):  
Vladimir Essau Martinez-Bello ◽  
Fabian Sanchis-Gomar ◽  
Ana Lucia Nascimento ◽  
Federico V. Pallardo ◽  
Sandra Ibañez-Sania ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Hematological Parameters ◽  
Sprint Training ◽  
Improve Performance

Maximal aerobic power in high-altitude runners

1993 ◽  
Vol 20 (4) ◽  
pp. 395-400 ◽  
Author(s):  
L.P. Greksa ◽  
H. Spielvogel ◽  
L. Paredes-Fernandez
Keyword(s):  
High Altitude ◽  
Aerobic Power ◽  
Maximal Aerobic Power

Maximal aerobic power in trained youths at high altitude

1982 ◽  
Vol 9 (3) ◽  
pp. 201-209 ◽  
Author(s):  
L.P. Greksa ◽  
J.D. Haas ◽  
T.L. Leatherman ◽  
H. Spielvogel ◽  
M. Paz Zamora ◽  
...  
Keyword(s):  
High Altitude ◽  
Aerobic Power ◽  
Maximal Aerobic Power

Endocrine responses to acute and chronic high-altitude exposure (4,300 meters): modulating effects of caloric restriction

2006 ◽  
Vol 290 (6) ◽  
pp. E1078-E1088 ◽  
Author(s):  
Kimberly E. Barnholt ◽  
Andrew R. Hoffman ◽  
Paul B. Rock ◽  
Stephen R. Muza ◽  
Charles S. Fulco ◽  
...  
Keyword(s):  
Body Weight ◽  
High Altitude ◽  
Sea Level ◽  
Caloric Restriction ◽  
Thyroid Stimulating Hormone ◽  
Normal Weight ◽  
Morning Cortisol ◽  
Maintain Body Weight ◽  
Baseline Values ◽  
The Difference

High-altitude anorexia leads to a hormonal response pattern modulated by both hypoxia and caloric restriction (CR). The purpose of this study was to compare altitude-induced neuroendocrine changes with or without energy imbalance and to explore how energy sufficiency alters the endocrine acclimatization process. Twenty-six normal-weight, young men were studied for 3 wk. One group [hypocaloric group (HYPO), n = 9] stayed at sea level and consumed 40% fewer calories than required to maintain body weight. Two other groups were deployed to 4,300 meters (Pikes Peak, CO), where one group (ADQ, n = 7) was adequately fed to maintain body weight and the other [deficient group (DEF), n = 10] had calories restricted as above. HYPO experienced a typical CR-induced reduction in many hormones such as insulin, testosterone, and leptin. At altitude, fasting glucose, insulin, and epinephrine exhibited a muted rise in DEF compared with ADQ. Free thyroxine, thyroid-stimulating hormone, and norepinephrine showed similar patterns between the two altitude groups. Morning cortisol initially rose higher in DEF than ADQ at 4,300 meters, but the difference disappeared by day 5. Testosterone increased in both altitude groups acutely but declined over time in DEF only. Adiponectin and leptin did not change significantly from sea level baseline values in either altitude group regardless of energy intake. These data suggest that hypoxia tends to increase blood hormone concentrations, but anorexia suppresses elements of the endocrine response. Such suppression results in the preservation of energy stores but may sacrifice the facilitation of oxygen delivery and the use of oxygen-efficient fuels.

Ventilation in newborn rats after gestation at simulated high altitude

1991 ◽  
Vol 70 (3) ◽  
pp. 1146-1151 ◽  
Author(s):  
R. D. Gleed ◽  
J. P. Mortola
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
High Altitude ◽  
Sea Level ◽  
Body Weight Gain ◽  
Female Rats ◽  
Metabolic Adaptation ◽  
Newborn Rats ◽  
Pregnant Rats

Pregnant rats were kept at a simulated altitude of 4,500 m (PO2 91 Torr) for the whole of gestation and returned to sea level 1 day after giving birth. During pregnancy, body weight gain and food intake were approximately 30% less than in controls at sea level. Measurements were made on the 1-day-old (HYPO) pups after a few hours at sea level. In normoxia, ventilation (VE) measured by flow plethysmography was more (+17%) and O2 consumption (VO2) measured by a manometric method was less (-19%) than in control (CONT) pups; in HYPO pups VE/VO2 was 44% greater than in CONT pups. In acute hyperoxia, VE/VO2 of HYPO and CONT pups decreased by a similar amount (15-20%), indicating some limitation in O2 availability for both groups of pups in normoxia. However, VE/VO2 of HYPO pups, even in hyperoxia, remained above (+34%) that of CONT pups. HYPO pups weighed slightly less than CONT pups, their lungs were hypoplastic, and their hearts were a larger fraction of body weight. An additional group of female rats was acclimatized (8 days) to high altitude before insemination. During pregnancy, body weight gain and food intake of these females were similar to those of pregnant rats at sea level. Measurements on the 1-day-old pups of this group were similar to those of HYPO pups. We conclude that newborn rats born after hypoxic gestation present metabolic adaptation (low VO2) and acclimatization (high VE/VO2), possibly because of hypoxemia. Maternal acclimatization before insemination substantially alters maternal growth in hypoxia but does not affect neonatal outcome.

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