Restricted postexercise pulmonary diffusion capacity does not impair maximal transport for O2

Hanel, Birgitte; Clifford, Philip S.; Secher, Niels H.

doi:10.1152/jappl.1994.77.5.2408

Cited by 80 publications

(96 citation statements)

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“…The DM component of the lung diffusing capacity may be reduced during exercise by interstitial edema; however, this reduction does not seem to affect O 2 transport (Hanel et al, 1994 exercise in hypoxia, due to higher pulmonary artery pressures in hypoxia than in normoxia (Dehnert et al, 2006;Maggiorini, 2006). Pulmonary artery hypertension may be prevented during exercise in acute hypoxia with 5-phosphodiesterase inhibitors (sildenafil) (Ricart et al, 2005;Richalet et al, 2005).…”

Section: Oxygen Diffusing Capacity In the Lungsmentioning

confidence: 99%

Air to Muscle O₂Delivery during Exercise at Altitude

Calbet

Lundby

2009

High Altitude Medicine & Biology

102

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Calbet, José, and Carsten Lundby. High Alt. Med. & Biol. 10.123-134, 2009.-Hypoxia-induced hyperventilation is critical to improve blood oxygenation, particularly when the arterial Po 2 lies in the steep region of the O 2 dissociation curve of the hemoglobin (ODC). Hyperventilation increases alveolar Po 2 and, by increasing pH, left shifts the ODC, increasing arterial saturation (Sao 2 ) 6 to 12 percentage units. Pulmonary gas exchange (PGE) is efficient at rest and, hence, the alveolar-arterial Po 2 difference (Pao 2 ÀPao 2 ) remains close to 0 to 5 mm Hg. The (Pao 2 ÀPao 2 ) increases with exercise duration and intensity and the level of hypoxia. During exercise in hypoxia, diffusion limitation explains most of the additional Pao 2 ÀPao 2 . With altitude, acclimatization exercise (Pao 2 ÀPao 2 ) is reduced, but does not reach the low values observed in high altitude natives, who possess an exceptionally high DLo 2 . Convective O 2 transport depends on arterial O 2 content (Cao 2 ), cardiac output (Q), and muscle blood flow (LBF). During whole-body exercise in severe acute hypoxia and in chronic hypoxia, peak Q and LBF are blunted, contributing to the limitation of maximal oxygen uptake (Vo 2max ). During small-muscle exercise in hypoxia, PGE is less perturbed, Cao 2 is higher, and peak Q and LBF achieve values similar to normoxia. Although the Po 2 gradient driving O 2 diffusion into the muscles is reduced in hypoxia, similar levels of muscle O 2 diffusion are observed during small-mass exercise in chronic hypoxia and in normoxia, indicating that humans have a functional reserve in muscle O 2 diffusing capacity, which is likely utilized during exercise in hypoxia. In summary, hypoxia reduces Vo 2max because it limits O 2 diffusion in the lung.

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Section: Oxygen Diffusing Capacity In the Lungsmentioning

confidence: 99%

Air to Muscle O₂Delivery during Exercise at Altitude

Calbet

Lundby

2009

High Altitude Medicine & Biology

102

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“…As shown by Zeballos and Weisman 10 and the current study, prior intense exercise usually decreases PaCO2 9 resulting in a lower PaCO2 in the second bout of exercise in comparison with the first; 8,9 although this finding is not consistent. 11,12 As well, PaO2 may increase in the second bout of exercise. 9 Since gas exchange does not decline, and may even improve during the second exercise bout, any pulmonary edema triggered by intense exercise 21 would be too mild to affect diffusion.…”

Section: The Effects Of Prior Exercise On Paco2mentioning

confidence: 99%

“…The effects of prior exercise on ABG's have been studied in humans 8,9,11,12 to evaluate diffusion limitation as a mechanism of exercise-induced hypoxemia. Since this study uses two sequential exercise protocols, our study can be considered to have used prior exercise to examine ABG's.…”

Section: The Effects Of Prior Exercise On Paco2mentioning

confidence: 99%

“…To date, no such study has addressed the use of repeat exercise to improve breathing in subjects with extreme obesity. There are data to show that PaCO2 during the second bout of exercise in non-obese humans and horses is usually lower in the second bout in comparison with the first [8][9][10] although other studies have report conflicting results, 11,12 while mean arterial oxygen pressure (PaO2) may increase in the second bout of exercise. 9 If repeat exercise reduces PaCO2 in subjects with extreme obesity, this reduction in PaCO2 must be caused by something other than a reduction in mechanical constraint, as weight loss would not have occurred during one test session.…”

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confidence: 99%

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Prior intense exercise reduces arterial carbon dioxide pressure in extreme obesity

Zavorsky

Kim²,

Cass³

et al. 2010

CIM

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Clin Invest Med 2010; 33 (5): E321-E334. AbstractPurpose: Unlike normal weight individuals, individuals with extreme obesity do not show a decrease in arterial carbon dioxide pressure (PaCO2) from rest to peak exercise. This indicates that breathing is compromised. The objective of this study was to determine if prior high intensity exercise lowers PaCO2 in comparison with a first bout, normalized for the same metabolic rate. Methods: Oxygen consumption during incremental, ramped exercise was matched to constant workload exercise (75% of peak power). Both protocols were to volitional exhaustion 39 ± 8 min apart. Eleven obese subjects (BMI = 47 ± 8 kg/m 2 , aerobic capacity = 2.3 ± 0.6 L/min) were evaluated. Forty paired samples were obtained at the same metabolic rate between the two protocols. Results: The mean absolute difference and 95% CI were large for arterial oxygen pressure (PaO2) = 9 (6, 11) mmHg and alveolar to arterial oxygen pressure difference (Aa-DO2) = 7 (5, 8) mmHg. The mean absolute difference for arterial oxyhemoglobin saturation (%SaO2) = 0.5 (0.4, 0.7) %; PaCO2 = 4 (3, 4) mmHg; physiological dead space to tidal volume ratio (VD/VT) = 0.04 (0.03, 0.05); and alveolar ventilation (VA) = 3 (2, 4) L/min. The recovery period after the first bout of exercise reduced the PaCO2 by 3 mmHg when matched for similar metabolic rates. Constant workload exercise predicted VA, %SaO2, VD/VT, and PaCO2, but not PaO2 or AaDO2 during incremental exercise at similar metabolic rates. Conclusion: Given a sufficient chemical stimulus, obese subjects will attempt to breathe more, although this does not mean more VA, which removes CO2.In normal-weight individuals (Body mass index or BMI = 18.5 to 24.9 kg/m 2 ), arterial carbon dioxide pressure (PaCO2) usually decreases from rest to peak exercise. The drop in PaCO2 is about 5 to 6 mmHg (from a resting value of 38 -40 mmHg to a peak exercise value of 34 mmHg). [1][2][3] In contrast, evidence suggests that subjects with extreme obesity (BMI 40 kg/m 2 ) maintain PaCO2 from rest to peak exercise. 4,5 A PaCO2 35.0 mmHg during strenuous exercise suggests poor compensatory exercise hyperventilation, and PaCO2 38.0 mmHg suggests absence of a complete hyperventilatory response. 6 Of course, those definitions suggest that hyperventilation during exercise is only "compensatory" if it is necessary to prevent decreases in arterial oxygen pressure (PaO2). If PaCO2 does not decrease between rest and peak exer-ORIGINAL RESEARCH

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“…Sıçrama kuvveti olarak bilinen patlayıcı kuvvet, başlama kuvveti ve elastik kuvvet, çabuk kuvvetin alt dalları olup maksimal kuvvetten doğrudan etkilenmektedir. Sadece kasılabilir bileşenin etkisi ölçülmek isteniyorsa squat sıçrama (SS), hem kasılabilir hem de visko-elastik bileşenin etkisi ölçülmek isteniyorsa aktif sıçrama (AS) hareketi kullanılır (13). Aktif sıçrama yüksekliği ve squat sıçrama yüksek-liği arasındaki fark (AS-SS) elastik kuvvet hakkın-da bilgi verir.…”

Section: Introductionunclassified

Yüksek irtifanın farklı sıçrama performansları üzerine etkilerinin incelenmesi

Orhan¹,

Yarım²,

Bilgin³

et al. 2015

Ankara Üniversitesi Beden Eğitimi Ve Spor Yüksekokulu SPORMETRE Beden Eğitimi Ve Spor Bilimleri Dergisi

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THE EFFECT OF MODARATE ALTITUDE ON SQUAT AND COUNTER MOVEMENT JUMPING PERFORMANCEAbstract: The purpose of this study was to determine the effect of moderate altitude on Squat and Counter Movement Jump. The study included thirteen sedentary male volunteers in Gazi University School of Physical Education and Sport. The subjects had an age range 22.2±1.7 years, height of 175.0±4.3 cm and body weight 71.0±10.4 kg. Test data were obtained through Bosco Ergo Jump measurement equipment. Totally 2 measurements (counter movement and squat jumps) were done during study, the first one of which was in Ilgaz/Çankırı (1880m), the second in Ankara (856m) Laboratory of Gazi University. Statistical analysis was conducted using the SPSS 16.0 paired simple t-test matched pairs test between the 856m and 1880m. According to the results, a paired sample t-test was used in comparisons between the groups. A significance level of p < .05 was used in analysis. The results of this study, there was significant difference between the two different measurements. Squat and counter movement jumps performances are increase the moderate altitude.

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Restricted postexercise pulmonary diffusion capacity does not impair maximal transport for O2

Cited by 80 publications

References 0 publications

Air to Muscle O₂Delivery during Exercise at Altitude

Air to Muscle O₂Delivery during Exercise at Altitude

Prior intense exercise reduces arterial carbon dioxide pressure in extreme obesity

Yüksek irtifanın farklı sıçrama performansları üzerine etkilerinin incelenmesi

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Restricted postexercise pulmonary diffusion capacity does not impair maximal transport for O2

Cited by 80 publications

References 0 publications

Air to Muscle O2Delivery during Exercise at Altitude

Air to Muscle O2Delivery during Exercise at Altitude

Prior intense exercise reduces arterial carbon dioxide pressure in extreme obesity

Yüksek irtifanın farklı sıçrama performansları üzerine etkilerinin incelenmesi

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Air to Muscle O₂Delivery during Exercise at Altitude

Air to Muscle O₂Delivery during Exercise at Altitude