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The Effect of an Olympic Distance Triathlon on Pulmonary Diffusing Capacity and its Recovery 24 Hours Later. J Hum Kinet 2021; 80:83-92. [PMID: 34868419 PMCID: PMC8607763 DOI: 10.2478/hukin-2021-0108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Olympic distance triathlon includes maximal exercise bouts with transitions between the activities. This study investigated the effect of an Olympic distance triathlon (1.5-km swim, 40-km bike, 10-km run) on pulmonary diffusion capacity (DLCO). In nine male triathletes (age: 24 ± 4.7 years), we measured DLCO and calculated the DLCO to alveolar volume ratio (DLCO/VA) and performed spirometry testing before a triathlon (pre-T), 2 hours after the race (post-T), and the day following the race (post-T-24 h). DLCO was measured using the 9-s breath-holding method. We found that (1) DLCO decreased significantly between pre- and post-T values (38.52 ± 5.44 vs. 35.92 ± 6.63 ml∙min-1∙mmHg-1) (p < 0.01) and returned to baseline at post-T-24 h (38.52 ± 5.44 vs. 37.24 ± 6.76 ml∙min-1∙mmHg-1, p > 0.05); (2) DLCO/VA was similar at the pre-, post- and post-T-24 h DLCO comparisons; and (3) forced expiratory volume in the first second (FEV1) and mean forced expiratory flow during the middle half of vital capacity (FEF25-75%) significantly decreased between pre- and post-T and between pre- and post-T-24-h (p < 0.02). In conclusion, a significant reduction in DLCO and DLCO/VA 2 hours after the triathlon suggests the presence of pulmonary interstitial oedema. Both values returned to baseline 24 hours after the race, which reflects possible mild and transient pulmonary oedema with minimal physiological significance.
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García I, Drobnic F, Pons V, Viscor G. Swimming exercise transiently decrease lung diffusing capacity in elite swimmers. J Sports Med Phys Fitness 2020; 61:666-672. [PMID: 33146491 DOI: 10.23736/s0022-4707.20.11302-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Swimmers have larger lungs and a higher diffusion capacity than other athletes, but it remains unknown whether swimming exercise changes lung diffusing properties. This study aimed to evaluate modifications in pulmonary alveolar-capillary diffusion after swimming exercise. METHODS The participants were 21 elite level swimmers, including 7 females and 14 males, with a training volume of 45-70 kilometers of swimming per week. The single-breath method was used to measure the lung diffusing capacity for carbon monoxide (DLCO and the transfer coefficient of the lungs for carbon monoxide (K<inf>CO</inf>) before and after 10 training sessions over 4 weeks along 207 pre- to postevaluations. RESULTS Swimming training consistently decreased lung diffusion capacity during the follow-up period, both DL<inf>CO</inf> (44.4±8.1 to 43.3±8.9 mL·min-1·mmHg-1, P=0.047, ŋ2<inf>p</inf>=0.55) and K<inf>CO</inf> (5.92±0.79 to 5.70±0.81 mL·min-1·mmHg-1·L-1, P=0.003, ŋ2<inf>p</inf>=0.75). CONCLUSIONS Elite swimmers experience a subclinical impairment in lung diffusing capacity after swimming exercise, but the stress caused by swimming on the lungs and the acute reduction in DL<inf>CO</inf> does not lead to physiological dysfunction.
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Affiliation(s)
- Iker García
- Section of Physiology, Department of Cellular Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona, Spain - .,Department pf Physiology and Nutrition, Centre d'Alt Rendiment (CAR), Barcelona, Spain -
| | | | - Victoria Pons
- Department pf Physiology and Nutrition, Centre d'Alt Rendiment (CAR), Barcelona, Spain
| | - Ginés Viscor
- Section of Physiology, Department of Cellular Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona, Spain
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3
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García I, Drobnic F, Pons V, Viscor G. Changes in Lung Diffusing Capacity of Elite Artistic Swimmers During Training. Int J Sports Med 2020; 42:227-233. [PMID: 32851635 DOI: 10.1055/a-1212-1020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Artistic swimmers (AS) are exposed to repeated apnoeas in the aquatic environment during high intensity exercise provoking specific physiological responses to training, apnoea, and immersion. This study aimed to evaluate the changes in lung diffusing capacity in AS pre-, mid- and post-training in a combined session of apnoeic swimming, figures and choreography. Eleven elite female AS from the Spanish national team were the study's participants. The single-breath method was used to measure lung diffusing capacity for carbon monoxide (DLCO) and one-way repeated measures ANOVA was utilized to evaluate the statistical analysis. Basal values of DLCO were higher than normal for their age and height (33.6±4.9 mL·min-1·mmHg-1; 139±19%) and there were a significant interaction between DLCO and AS training (ŋ2 p=0.547). After the apnoeic swimming (mid-training) there was an increase in DLCO from basal to 36.7±7.3 mL·min-1·mmHg-1 (p=0.021), and after the figures and choreography (post-training) there was a decrease compared to mid-training (32.3±4.6 mL·min-1·mmHg-1, p=0.013). Lung diffusing capacity changes occur during AS training, including a large increase after apnoeic swimming. There were no differences in lung diffusing capacity from pre- to post-training, although large inter-individual variability was observed.
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Affiliation(s)
- Iker García
- Secció de Fisiologia, Departament de Biologia Cel lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.,Departament de Fisiologia i Nutricio, Centre d'Alt Rendiment, Sant Cugat Del Valles, Spain
| | | | - Victoria Pons
- Departament de Fisiologia i Nutricio, Centre d'Alt Rendiment, Sant Cugat Del Valles, Spain
| | - Ginés Viscor
- Secció de Fisiologia, Departament de Biologia Cel lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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4
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Nordlund B, James A, Ebersjö C, Hedlin G, Broström EB. Differences and similarities between bronchopulmonary dysplasia and asthma in schoolchildren. Pediatr Pulmonol 2017. [PMID: 28636794 DOI: 10.1002/ppul.23741] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND The long-term respiratory characteristics of ex-preterm children with bronchopulmonary dysplasia (BPD) are not established. The objective of this study was to describe hallmarks of BPD at school age in comparison to children with atopic asthma. METHODS This study was a cross-sectional descriptive comparative study in a hospital-based setting. Thirty schoolchildren diagnosed with BPD (10.4 years/born at 26.6 weeks' gestation) and 30 age- and sex-matched children with asthma and sensitized to airborne allergens (IgE >0.35 kUA /L) were analyzed. Measurements included fraction of exhaled nitric oxide (FENO, ppb), dynamic and static lung function, and bronchial provocation with methacholine (PD:20) and mannitol (PD:15), as well as an evaluation of respiratory symptoms using the asthma control test (C-ACT). RESULTS Lung function measures (FEV1% 77 vs 84, FEV1/FVC% 85 vs 91, FEF50% 61 vs 80) and carbon monoxide diffusion capacity (DLCO%, 81 vs 88) were all reduced in children with BPD compared to asthma (P values <0.042). FENO values were also significantly lower in children with BPD (12 vs 23, P = 0.019). The proportion of positive methacholine tests (74% vs 93%, P = 0.14) was comparable between BPD and asthma. However, less responsiveness towards mannitol (19% vs 61%, P = 0.007) and fewer self-reported symptoms (C-ACT, median 26 vs 24, P = 0.003) were found in the BPD group. CONCLUSION Respiratory hallmarks of BPD at school-age were reduced lung function, limited responsiveness towards indirectly acting mannitol but hyper-responsiveness towards direct acting methacholine and impairment in diffusion capacity. Children with BPD displayed less evidence of airway inflammation compared with atopic asthma.
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Affiliation(s)
- Björn Nordlund
- Astrid Lindgren Children's Hospital, Lung and Allergy Unit, Karolinska University Hospital, Stockholm, Sweden.,Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Anna James
- Experimental Asthma and Allergy Research, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Christina Ebersjö
- Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden.,Sach's Children and Youth Hospital, Södersjukhuset, Stockholm, Sweden
| | - Gunilla Hedlin
- Astrid Lindgren Children's Hospital, Lung and Allergy Unit, Karolinska University Hospital, Stockholm, Sweden.,Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Eva B Broström
- Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden.,Sach's Children and Youth Hospital, Södersjukhuset, Stockholm, Sweden
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Zavorsky GS, Hsia CCW, Hughes JMB, Borland CDR, Guénard H, van der Lee I, Steenbruggen I, Naeije R, Cao J, Dinh-Xuan AT. Standardisation and application of the single-breath determination of nitric oxide uptake in the lung. Eur Respir J 2017; 49:49/2/1600962. [PMID: 28179436 DOI: 10.1183/13993003.00962-2016] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 10/26/2016] [Indexed: 01/03/2023]
Abstract
Diffusing capacity of the lung for nitric oxide (DLNO), otherwise known as the transfer factor, was first measured in 1983. This document standardises the technique and application of single-breath DLNO This panel agrees that 1) pulmonary function systems should allow for mixing and measurement of both nitric oxide (NO) and carbon monoxide (CO) gases directly from an inspiratory reservoir just before use, with expired concentrations measured from an alveolar "collection" or continuously sampled via rapid gas analysers; 2) breath-hold time should be 10 s with chemiluminescence NO analysers, or 4-6 s to accommodate the smaller detection range of the NO electrochemical cell; 3) inspired NO and oxygen concentrations should be 40-60 ppm and close to 21%, respectively; 4) the alveolar oxygen tension (PAO2 ) should be measured by sampling the expired gas; 5) a finite specific conductance in the blood for NO (θNO) should be assumed as 4.5 mL·min-1·mmHg-1·mL-1 of blood; 6) the equation for 1/θCO should be (0.0062·PAO2 +1.16)·(ideal haemoglobin/measured haemoglobin) based on breath-holding PAO2 and adjusted to an average haemoglobin concentration (male 14.6 g·dL-1, female 13.4 g·dL-1); 7) a membrane diffusing capacity ratio (DMNO/DMCO) should be 1.97, based on tissue diffusivity.
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Affiliation(s)
- Gerald S Zavorsky
- Dept of Respiratory Therapy, Georgia State University, Atlanta, GA, USA
| | - Connie C W Hsia
- Dept of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Colin D R Borland
- Dept of Medicine, University of Cambridge, Hinchingbrooke Hospital, Huntingdon, UK
| | - Hervé Guénard
- Dept of Physiology and Pulmonary Laboratory, University of Bordeaux and CHU, Bordeaux, France
| | - Ivo van der Lee
- Dept of Pulmonary Diseases, Spaarne Hospital, Hoofddorp, The Netherlands
| | | | - Robert Naeije
- Dept of Cardiology, Erasme University Hospital, Brussels, Belgium
| | - Jiguo Cao
- Dept of Statistics and Actuarial Science, Simon Fraser University, Burnaby, BC, Canada
| | - Anh Tuan Dinh-Xuan
- Dept of Physiology, Cochin Hospital, Paris Descartes University, Paris, France
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6
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Galy’s Response to Zavorsky. Int J Sports Physiol Perform 2014; 9:743. [DOI: 10.1123/ijspp.2014-0308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Comment on Olivier Galy et al, "aggravation of pulmonary diffusing capacity in highly trained athletes by 6 weeks of low-volume, low-intensity training". Int J Sports Physiol Perform 2014; 9:742. [PMID: 25171539 DOI: 10.1123/ijspp.2014-0086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Fitzgerald NM, Kennedy B, Fitzgerald DA, Selvadurai H. Diffusion capacity of carbon monoxide (DLCO) pre- and post-exercise in children in health and disease. Pediatr Pulmonol 2014; 49:782-9. [PMID: 24395764 DOI: 10.1002/ppul.22925] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 07/30/2013] [Indexed: 11/10/2022]
Abstract
RATIONALE A decrease in diffusion capacity for carbon monoxide (DLCO) after exercise has been reported in healthy adults. There is limited information for post-exercise DLCO available in children either in health or in disease. OBJECTIVES To evaluate (1) reproducibility of DLCO measures in children, (2) differences in DLCO between elite athletic swimmers (AS), stable cystic fibrosis patients (CF), and healthy controls (Con) at rest; and (3) after a maximal treadmill exercise test. METHODS Participants performed spirometry and DLCO at baseline, a maximal treadmill exercise test and repeated DLCO measures for 2 hr after cessation of exercise. RESULTS The mean (SD) co-efficient of variation between baseline DLCO tests was 2.49% (1.86%). In girls, the mean baseline DLCO (ml/min/mmHg) was 18.61 (4.15) in CF, 22.32 (4.79) in controls and 27.18 (5.33) in AS. In boys: 23.68 (5.31) in CF, 28.09 (9.95) in controls and 37.75 (9.46) in AS. Baseline DLCO was significantly higher in AS than in CF patients (P < 0.01). In girls post-exercise, the greatest mean decrease in DLCO from baseline was -7.50% to -12.83% and in boys -6.92% to -17.71%. The decline in DLCO was less important in the athletes than the other groups (P < 0.05). CONCLUSIONS DLCO is highly repeatable in children. AS have an increased DLCO at rest compared to both children with CF and controls. There is a decline from baseline to post-exercise DLCO and while there are disease-specific differences, the general pattern of change in DLCO measures after exercise is similar in children to adults.
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Affiliation(s)
- Nicholas M Fitzgerald
- University of New South Wales, Sydney, Australia; Department of Respiratory Medicine, The Children's Hospital at Westmead, Sydney, Australia
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9
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Abstract
There is comparatively little data on diffusion capacity in children during exercise. With the advent of improved technology, there is an increasing interest in exercise testing of children in order to predict the evolution of lung disease. In addition to the standard measure of exercise capacity, the VO(2max), interest is evolving in the consequences of alterations in diffusion capacity which may be unmasked with exercise. This review will consider what is known about diffusion capacity with exercise in children with well documented lung disease in the form of cystic fibrosis, healthy controls and swimmers as elite athletes with the largest lung volumes.
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10
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Stickland MK, Lindinger MI, Olfert IM, Heigenhauser GJF, Hopkins SR. Pulmonary gas exchange and acid-base balance during exercise. Compr Physiol 2013; 3:693-739. [PMID: 23720327 PMCID: PMC8315793 DOI: 10.1002/cphy.c110048] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
As the first step in the oxygen-transport chain, the lung has a critical task: optimizing the exchange of respiratory gases to maintain delivery of oxygen and the elimination of carbon dioxide. In healthy subjects, gas exchange, as evaluated by the alveolar-to-arterial PO2 difference (A-aDO2), worsens with incremental exercise, and typically reaches an A-aDO2 of approximately 25 mmHg at peak exercise. While there is great individual variability, A-aDO2 is generally largest at peak exercise in subjects with the highest peak oxygen consumption. Inert gas data has shown that the increase in A-aDO2 is explained by decreased ventilation-perfusion matching, and the development of a diffusion limitation for oxygen. Gas exchange data does not indicate the presence of right-to-left intrapulmonary shunt developing with exercise, despite recent data suggesting that large-diameter arteriovenous shunt vessels may be recruited with exercise. At the same time, multisystem mechanisms regulate systemic acid-base balance in integrative processes that involve gas exchange between tissues and the environment and simultaneous net changes in the concentrations of strong and weak ions within, and transfer between, extracellular and intracellular fluids. The physicochemical approach to acid-base balance is used to understand the contributions from independent acid-base variables to measured acid-base disturbances within contracting skeletal muscle, erythrocytes and noncontracting tissues. In muscle, the magnitude of the disturbance is proportional to the concentrations of dissociated weak acids, the rate at which acid equivalents (strong acid) accumulate and the rate at which strong base cations are added to or removed from muscle.
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Affiliation(s)
- Michael K. Stickland
- Division of Pulmonary Medicine, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Michael I. Lindinger
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - I. Mark Olfert
- Robert C. Byrd Health Sciences Center, Center for Cardiovascular and Respiratory Sciences, Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, West Virginia
| | | | - Susan R. Hopkins
- Departments of Medicine and Radiology, University of California, San Diego, San Diego, California
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11
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de Bisschop C, Martinot JB, Leurquin-Sterk G, Faoro V, Guénard H, Naeije R. Improvement in lung diffusion by endothelin A receptor blockade at high altitude. J Appl Physiol (1985) 2011; 112:20-5. [PMID: 21979801 DOI: 10.1152/japplphysiol.00670.2011] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Lung diffusing capacity has been reported variably in high-altitude newcomers and may be in relation to different pulmonary vascular resistance (PVR). Twenty-two healthy volunteers were investigated at sea level and at 5,050 m before and after random double-blind intake of the endothelin A receptor blocker sitaxsentan (100 mg/day) vs. a placebo during 1 wk. PVR was estimated by Doppler echocardiography, and exercise capacity by maximal oxygen uptake (Vo(2 max)). The diffusing capacities for nitric oxide (DL(NO)) and carbon monoxide (DL(CO)) were measured using a single-breath method before and 30 min after maximal exercise. The membrane component of DL(CO) (Dm) and capillary volume (Vc) was calculated with corrections for hemoglobin, alveolar volume, and barometric pressure. Altitude exposure was associated with unchanged DL(CO), DL(NO), and Dm but a slight decrease in Vc. Exercise at altitude decreased DL(NO) and Dm. Sitaxsentan intake improved Vo(2 max) together with an increase in resting and postexercise DL(NO) and Dm. Sitaxsentan-induced decrease in PVR was inversely correlated to DL(NO). Both DL(CO) and DL(NO) were correlated to Vo(2 max) at sea level (r = 0.41-0.42, P < 0.1) and more so at altitude (r = 0.56-0.59, P < 0.05). Pharmacological pulmonary vasodilation improves the membrane component of lung diffusion in high-altitude newcomers, which may contribute to exercise capacity.
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Affiliation(s)
- Claire de Bisschop
- Laboratory of Physiologic Adaptations to Physical Activities, UPRES EA 3813, Poitiers University, Poitiers, France
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12
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Storebø ML, Hope A, Vaagbø G, Thorsen E. Postexercise reduction in lung diffusion capacity is not attenuated by skin cooling. Clin Physiol Funct Imaging 2008; 28:403-8. [PMID: 18700837 DOI: 10.1111/j.1475-097x.2008.00821.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pulmonary diffusion capacity for carbon monoxide (DL(CO)) is reduced by approximately 10% 1-6 h after maximal exercise. The mechanisms may be interstitial alveolar oedema and reduced pulmonary capillary blood volume. It was hypothesized that thermal stress following exercise contributes to the reduction in DL(CO), and that skin cooling would attenuate the postexercise reduction in DL(CO). Cutaneous vascular conductance (CVC), mean surface temperature (MST), rectal temperature and DL(CO) were measured before and 90 min after maximal incremental cycle exercise. Thereafter, the subjects were exposed to cold air without eliciting shivering one day and another day served as control. The measurements were repeated 120 min after exercise. Twelve healthy subjects (six male) aged 20-27 years were studied. DL(CO) was reduced by 7.1% (SD = 6.3%, P = 0.003) and 7.6% (SD = 5.3%, P<0.001) 90 and 120 min after exercise in the control experiment. It was reduced by 5.6% (SD = 5.5%, P = 0.014) 90 min after exercise and remained reduced by 6.1% (SD = 6.1%, P = 0.012) after cooling despite a significant reduction in CVC and in MST from 31.9 (SD = 0.6) degrees C to 27.4 (SD = 1.9) degrees C. We conclude that the postexercise reduction in DL(CO) is present when thermal status is restored after exercise, and that it is not influenced by further skin surface cooling.
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Calbet JA, Robach P, Lundby C, Boushel R. Is pulmonary gas exchange during exercise in hypoxia impaired with the increase of cardiac output? Appl Physiol Nutr Metab 2008; 33:593-600. [DOI: 10.1139/h08-010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During exercise in humans, the alveolar–arterial O2 tension difference ((A–a)DO2) increases with exercise intensity and is an important factor determining the absolute level of oxygen binding to hemoglobin and therefore the level of systemic oxygen transport. During exercise in hypoxia, the (A–a)DO2 is accentuated. Using the multiple inert gas elimination technique it has been shown that during exercise in acute hypoxia the contribution of ventilation–perfusion inequality to (A–a)DO2 is rather small and in the absence of pulmonary edema intrapulmonary shunts can be ruled out. This implies that the main mechanism limiting pulmonary gas exchange is diffusion limitation. It is presumed that an elevation of cardiac output during exercise in acute hypoxia should increase the (A–a)DO2. However, no studies have examined how variations in cardiac output independently affect pulmonary diffusion with increases in exercise intensity. We have consistently observed that during steady-state, submaximal (100–120 W) exercise on the cycle ergometer in hypoxia the lung can accommodate an increase in cardiac output of ~2 L·min–1 without any significant effect on pulmonary gas exchange. This result contrasts with the predicted effect of cardiac output on (A–a)DO2 using the model of Piiper and Scheid, and thus indicates that an elevation of cardiac output is not necessarily accompanied by a reduction of mean transit time and (or) diffusion limitation during submaximal exercise in acute hypoxia. It remains to be determined what is the influence of changes in cardiac output per se on pulmonary gas exchange during high-intensity exercise.
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Affiliation(s)
- José A.L. Calbet
- Department of Physical Education, University of Las Palmas de Gran Canaria, 35017, Spain
- The Copenhagen Muscle Research Centre, Rigshospitalet, Denmark
- École Nationale de Ski et d’Alpinisme, Chamonix, France
- Laboratoire “Réponses cellulaires et fonctionnelles à l’hypoxie”, EA 2363, Université Paris 13, Bobigny, France
- Department of Sport Science, Århus Universitet, Katrinebjergvej 89C, Denmark
| | - Paul Robach
- Department of Physical Education, University of Las Palmas de Gran Canaria, 35017, Spain
- The Copenhagen Muscle Research Centre, Rigshospitalet, Denmark
- École Nationale de Ski et d’Alpinisme, Chamonix, France
- Laboratoire “Réponses cellulaires et fonctionnelles à l’hypoxie”, EA 2363, Université Paris 13, Bobigny, France
- Department of Sport Science, Århus Universitet, Katrinebjergvej 89C, Denmark
| | - Carsten Lundby
- Department of Physical Education, University of Las Palmas de Gran Canaria, 35017, Spain
- The Copenhagen Muscle Research Centre, Rigshospitalet, Denmark
- École Nationale de Ski et d’Alpinisme, Chamonix, France
- Laboratoire “Réponses cellulaires et fonctionnelles à l’hypoxie”, EA 2363, Université Paris 13, Bobigny, France
- Department of Sport Science, Århus Universitet, Katrinebjergvej 89C, Denmark
| | - Robert Boushel
- Department of Physical Education, University of Las Palmas de Gran Canaria, 35017, Spain
- The Copenhagen Muscle Research Centre, Rigshospitalet, Denmark
- École Nationale de Ski et d’Alpinisme, Chamonix, France
- Laboratoire “Réponses cellulaires et fonctionnelles à l’hypoxie”, EA 2363, Université Paris 13, Bobigny, France
- Department of Sport Science, Århus Universitet, Katrinebjergvej 89C, Denmark
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Guenette JA, Sheel AW. Exercise-induced arterial hypoxaemia in active young women. Appl Physiol Nutr Metab 2007; 32:1263-73. [DOI: 10.1139/h07-122] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Studies examining pulmonary gas exchange during exercise have primarily focused on young healthy men, whereas the female response to exercise has received limited attention. Evidence is accumulating that the response of the lungs, airways, and (or) respiratory muscles to exercise is less than ideal and this may significantly compromise oxygen transport in certain groups of otherwise healthy, fit, active, male subjects. Women may be even more susceptible to exercise-induced pulmonary limitations than height-matched men, by virtue of their smaller lung volumes, lower maximal expiratory flow rates, and smaller diffusion surface areas. We have recently shown that exercise-induced arterial hypoxaemia (EIAH) is more prevalent and occurs at relatively lower fitness levels in females than in males. Despite this finding, few physiologically based mechanisms have been identified to explain why women may be more susceptible to EIAH than men. Potential mechanisms of EIAH include relative alveolar hypoventilation, ventilation–perfusion inequality, and diffusion limitation. Whether these mechanisms are different between sexes remains controversial. The primary purpose of this review is to summarize the available data on EIAH in women and to discuss potential sex-based mechanisms for gas exchange impairment. Furthermore, we discuss unresolved questions dealing with pulmonary system limitations during exercise in women.
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Affiliation(s)
- Jordan A. Guenette
- Health and Integrative Physiology Laboratory, School of Human Kinetics, The University of British Columbia, 6108 Thunderbird Blvd., Vancouver, BC V6T 1Z3
| | - A. William Sheel
- Health and Integrative Physiology Laboratory, School of Human Kinetics, The University of British Columbia, 6108 Thunderbird Blvd., Vancouver, BC V6T 1Z3
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MacNutt MJ, Guenette JA, Witt JD, Yuan R, Mayo JR, McKenzie DC. Intense hypoxic cycle exercise does not alter lung density in competitive male cyclists. Eur J Appl Physiol 2007; 99:623-31. [PMID: 17219166 DOI: 10.1007/s00421-006-0388-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2006] [Indexed: 10/23/2022]
Abstract
We tested the hypothesis that intense short duration hypoxic exercise would result in an increase in extravascular lung water (EVLW), as evidenced by an increase in lung density. Using computed tomography (CT), baseline lung density was obtained in eight highly trained male cyclists (mean +/- SD: age = 28 +/- 8 years; height = 180 +/- 9 cm; mass = 71.6 +/- 8.2 kg; VO2max= 65.0 +/- 5.2 ml kg min(-1)). Subjects then completed an intense hypoxic exercise challenge on a cycle ergometer and metabolic data, HR and %S(p)O2 were recorded throughout. While breathing 15% O2, subjects performed five 3 km cycling intervals (mean power, 286 +/- 20 W; HR = 91 +/- 4% HRmax) separated by 5 min of recovery. From a resting hypoxic S(p)O2 of 92 +/- 4%, subjects further desaturated during exercise to 76 +/- 3%. CT scans were repeated 76 +/- 10 min (range 63-88 min) following the completion of exercise. There was no change in lung density from pre (0.18 +/- 0.02 g ml(-1)) to post-exercise (0.18 +/- 0.04 g ml(-1)). The substantial reduction in S(p)O2 may be explained by a number of potential mechanisms, including decreased pulmonary diffusion capacity, alveolar hypoventilation, reduced red cell transit time, ventilation/perfusion inequality or a temperature and pH induced rightward-shift in the oxyhaemoglobin dissociation curve. Alternatively, the integrity of the blood gas barrier may have been disrupted without any measurable increase in lung density.
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Affiliation(s)
- M J MacNutt
- School of Human Kinetics, University of British Columbia, Vancouver, Canada.
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Sheel AW, Koehle MS, Guenette JA, Foster GE, Sporer BC, Diep TT, McKenzie DC. Human ventilatory responsiveness to hypoxia is unrelated to maximal aerobic capacity. J Appl Physiol (1985) 2006; 100:1204-9. [PMID: 16410378 DOI: 10.1152/japplphysiol.01127.2005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ventilatory responsiveness to hypoxia (HVR) has been reported to be different between highly trained endurance athletes and healthy sedentary controls. However, a linkage between aerobic capacity and HVR has not been a universal finding. The purpose of this study was to examine the relationship between HVR and maximal oxygen consumption (V̇o2 max) in healthy men with a wide range of aerobic capacities. Subjects performed a HVR test followed by an incremental cycle test to exhaustion. Participants were classified according to their maximal aerobic capacity. Those with a V̇o2 max of ≥60 ml·kg−1·min−1 were considered highly trained ( n = 13); those with a V̇o2 max of 50–60 ml·kg−1·min−1 were considered moderately-trained ( n = 18); and those with a V̇o2 max of <50 ml·kg−1·min−1 were considered untrained ( n = 24). No statistical differences were detected between the three groups for HVR ( P > 0.05), and the HVR values were variable within each group (range: untrained = 0.28–1.61, moderately trained = 0.23–2.39, and highly trained = 0.08–1.73 l·min·%arterial O2 saturation−1). The relationship between HVR and V̇o2 max was not statistically significant ( r = −0.1723; P > 0.05). HVR was also unrelated to maximal minute ventilation and ventilatory equivalents for O2 and CO2. We found that a spectrum of hypoxic ventilatory control is present in well-trained endurance athletes and moderately and untrained men. We interpret these observations to mean that other factors are more important in determining hypoxic ventilatory control than physical conditioning per se.
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Affiliation(s)
- A William Sheel
- School of Human Kinetics, The University of British Columbia, 210-6081 Univ. Blvd., Vancouver, BC, Canada V6T 1Z1.
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Zavorsky GS, Saul L, Decker A, Ruiz P. Radiographic evidence of pulmonary edema during high-intensity interval training in women. Respir Physiol Neurobiol 2006; 153:181-90. [PMID: 16516564 DOI: 10.1016/j.resp.2005.10.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2005] [Revised: 11/03/2005] [Accepted: 10/22/2005] [Indexed: 11/26/2022]
Abstract
The purpose was to determine if an intense interval training session could produce transient pulmonary edema in women. Fourteen females [(27+/-4 years; body mass index of 21.6+/-1.5 kg/m(2)); maximal oxygen consumption = 3.12+/-0.42 L/min] performed three sets of 5 min sea-level cycling exercise with 10-min recovery between each set. Average oxygen consumption at minute 5 of each set was 96+/-5% of maximum and arterial plasma lactate concentration at minute 5 of each set was 16.0+/-3.3 mmol/L. Chest radiographs were obtained before and 33.2+/-6.1 min after exercise. Four different chest radiologists independently reviewed the radiographs for edema, and scored seven validated radiographic characteristics on a three-point scale (0-2). The overall edema score increased from 1.3+/-1.6 before exercise to 1.9+/-2.0 after exercise [P<0.05; Delta = +0.7+/-1.8, 95% CI, 0.2 to +1.1]. This study shows that an intense interval training session can cause mild, detectable pulmonary edema in some women.
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Affiliation(s)
- Gerald S Zavorsky
- Department of Anesthesia, McGill University Health Center, 1650 Cedar Avenue, Room D10-144, Montreal, Que., Canada H3G 1A4.
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McKenzie DC, O'Hare TJ, Mayo J. The effect of sustained heavy exercise on the development of pulmonary edema in trained male cyclists. Respir Physiol Neurobiol 2005; 145:209-18. [PMID: 15705536 DOI: 10.1016/j.resp.2004.06.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2004] [Indexed: 11/22/2022]
Abstract
To determine whether intense, prolonged activity can induce transient pulmonary edema, eight highly trained male cyclists (mean +/- S.D.: age, 26.9 +/- 3.0 years; height, 179.9 +/- 5.7 cm; weight, 76.1 +/- 6.5 kg) performed a 45-min endurance cycle test (ECT). V(O2,max) was determined (4.84 +/- 0.4 L min(-1), 63.7 +/- 2.6 ml min(-1) g(-1)) and the intensity of exercise for the ECT was set at 10% below ventilatory threshold (approximately 76% V(O2, max) 300 +/- 25 W). Pre- and post-exercise pulmonary diffusion (DL(CO)) measurements and magnetic resonance imaging of the lung were made. DL(CO) and pulmonary capillary blood volume (VC) decreased 1h post-exercise by 12% (P = 0.004) and 21% (P = 0.017), respectively, but no significant change in membrane diffusing capacity (DM) was found. The magnetic resonance scans demonstrated a 9.4% increase (P = 0.043) in pulmonary extravascular water 90 min post-exercise. These data support the theory that high intensity, sustained exercise in well-trained athletes can result in transient pulmonary edema.
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Affiliation(s)
- D C McKenzie
- Allan McGavin Sports Medicine Centre and School of Human Kinetics, The University of British Columbia, 3055 Wesbrook Mall, Vancouver, BC, Canada V6T 1Z3.
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Zavorsky GS, Lands LC. Lung diffusion capacity for nitric oxide and carbon monoxide is impaired similarly following short-term graded exercise. Nitric Oxide 2005; 12:31-8. [PMID: 15631945 DOI: 10.1016/j.niox.2004.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2004] [Revised: 09/28/2004] [Accepted: 11/11/2004] [Indexed: 11/25/2022]
Abstract
Study aimed to determine whether short-term graded exercise affects single-breath lung diffusion capacity for nitric oxide (DLNO) and carbon monoxide (DLCO) similarly, and whether the DLNO/DLCO ratios during rest are altered post-exercise compared to pre-exercise. Eleven healthy subjects (age=29+/-6 years; weight=76.6+/-13.2 kg; height=177.9+/-13.2 cm; and maximal oxygen uptake or V(.-)(O(2max) = 52.7 +/- 9.3 ml kg(-1) min(-1))performed simultaneous single-breath DLNO and DLCO measurements at rest (inspired NO concentration=43.2+/-4.1 ppm, inspired CO concentration=0.30%) 15 min before and 2h after a graded exercise test to exhaustion (exercise duration=593+/-135 s). Resting DLNO and DLCO was similarly reduced 2h post-exercise (DLNO=-7.8+/-3.5%, DLCO=-10.3+/-6.9%, and P<0.05) due to reductions in pulmonary capillary blood volume (-11.3+/-9.0%, P<0.05) and membrane diffusing capacity for CO (-7.8+/-3.5%; P<0.05). The change in DLCO was reflected by the change in DLNO post-exercise such that 68% of the variance in the change in DLCO was accounted for by the variance in the change in DLNO (P<0.05). The DLNO/DLCO ratio was not altered post-exercise (5.87+/-0.37) compared to pre-exercise (5.70+/-0.34). We conclude that the decrease in single-breath DLNO and DLCO from pre- to post-exercise is similar, the magnitude of the change in DLCO closely reflects that of the change in DLNO, and single-breath DLNO/DLCO ratios are independent of the timing of measurement suggesting that using NO and CO transfer gases are valid in looking at short-term changes in lung diffusional conductance.
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Affiliation(s)
- Gerald S Zavorsky
- Department of Anesthesia, McGill University Health Center, 1650 Cedar Avenue, Room D10-144, Montreal, Que., Canada H3G 1A4.
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Abstract
Exercise affects lymphocytes as reflected in total blood counts and the lymphocyte proliferative response. In addition, the production of immunoglobulins is impaired and during exercise the natural killer cell activity increases followed by suppression in the recovery period. Cardiopulmonary adjustments play a major role in lymphocyte response to physical activity. During intense exercise, the activated sympathetic nervous system increases blood flow to muscle as blood flow to splanchnic organs decreases. After exercise, sympathetic tone and blood pressure becomes reduced. The spleen contains lymphocytes and blood resides in gut vessels. A change in blood flow to these organs could affect the number of circulating lymphocytes. Reduced production of immunoglobulins results from suppressed B-cell function and, in response to exercise, mucosal immunity appears to decrease. Pulmonary hyperventilation and enhanced pressure in pulmonary vessels induce increased permeability of airway epithelium and stress failure of the alveolar-capillary membrane during intense exercise. A physiological perspective is of importance for evaluation of the exercise-induced change in lymphocyte function and, in turn, to post-exercise increased susceptibility to infections.
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Affiliation(s)
- Henning Bay Nielsen
- Department of Anaesthesia, The Copenhagen Muscle Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
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Nielsen HB. Arterial desaturation during exercise in man: implication for O2 uptake and work capacity. Scand J Med Sci Sports 2003; 13:339-58. [PMID: 14617055 DOI: 10.1046/j.1600-0838.2003.00325.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Exercise-induced arterial hypoxaemia is defined as a reduction in the arterial O2 pressure (PaO2) by more than 1 kPa and/or a haemoglobin O2 saturation (SaO2) below 95%. With blood gas analyses ideally reported at the actual body temperature, desaturation is a consistent finding during maximal ergometer rowing. Arterial desaturation is most pronounced at the end of a maximal exercise bout, whereas the reduction in PaO2 is established from the onset of exercise. Exercise-induced arterial hypoxaemia is multifactorial. The ability to maintain a high alveolar O2 pressure (PAO2) is critical for blood oxygenation and this appears to be difficult in large individuals. A large lung capacity and, in turn, diffusion capacity seem to protect PaO2. A widening of the PAO2-PaO2 difference does indicate that a diffusion limitation, a ventilation-perfusion mismatch and/or a shunt influence the transport of O2 from alveoli to the pulmonary capillaries. An inspired O2 fraction of 0.30 reduces the widened PAO2-PaO2 difference by 75% and prevents a reduction of PaO2 and SaO2. With a marked increase in cardiac output, diffusion limitation combined with a fast transit time dominates the O2 transport problem. Furthermore, a postexercise reduction in pulmonary diffusion capacity suggests that the alveolo-capillary membrane is affected. An antioxidant attenuates oxidative burst by neutrophilic granulocytes, but it does not affect PaO2, SaO2 or O2 uptake (VO2), and the ventilatory response to maximal exercise also remains the same. It is proposed, though, that increased concentration of certain cytokines correlates to exercise-induced hypoxaemia as cytokines stimulate mast cells and basophilic granulocytes to degranulate histamine. The basophil count increases during maximal rowing. Equally, histamine release is associated with hypoxaemia and when the release of histamine is prevented, the reduction in PaO2 is attenuated. During maximal exercise, an extreme lactate spill-over to blood allows pH decrease to below 7.1 and according to the O2 dissociation curve this is critical for SaO2. When infusion of sodium bicarbonate maintains a stable blood buffer capacity, acidosis is attenuated and SaO2 increases from 89% to 95%. This enables exercise capacity to increase, an effect also seen when O2 supplementation to inspired air restores arterial oxygenation. In that case, exercise capacity increases less than can be explained by VO2 and CaO2. Furthermore, the change in muscle oxygenation during maximal exercise is not affected when hyperoxia and sodium bicarbonate attenuate desaturation. It is proposed that other organs benefit from enhanced O2 availability, and especially the brain appears to increase its oxygenation during maximal exercise with hyperoxia.
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Affiliation(s)
- Henning Bay Nielsen
- The Copenhagen Muscle Research Centre Department of Anaesthesia, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
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Stickland MK, Petersen SR, Haykowsky MJ, Taylor DA, Jones RL. The effects of cycle racing on pulmonary diffusion capacity and left ventricular systolic function. Respir Physiol Neurobiol 2003; 138:291-9. [PMID: 14609517 DOI: 10.1016/s1569-9048(03)00198-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The purpose of this study was to examine the effects of a 20 km cycle race (TT) on left ventricular (LV) systolic and pulmonary function in 12 endurance cyclists. Spirometry, single-breath diffusion capacity (DLCO) with partitioning of membrane (DM) and capillary blood volume (Vc) components and 2-D echocardiograms were performed before and after the TT. During the TT mean oxygen consumption was 3.79 +/- 0.5 L x min(-1) (83 +/- 5.5% of VO2max) and mean blood lactate was 8.4 +/- 2.4 mM. Following the TT, spirometry values were unchanged, however, DLCO and DM were significantly (P<0.05) reduced. LV systolic function was increased (P<0.05) immediately after exercise, while end-diastolic area was decreased (P<0.05) at all points during recovery. The reduction in DM was correlated with LV systolic function following the TT. This relationship suggests a cardiovascular contribution to pulmonary diffusion impairment following exercise.
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Affiliation(s)
- Michael K Stickland
- Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alta., Canada T6G 2H9
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Abstract
The respiratory system rarely limits exercise in the normal subject. In patients with chronic pulmonary processes or in the elite athlete, however, the respiratory system may indeed be the limiting factor. Common respiratory disorders include chest pain syndromes, cough, exercise-induced asthma, and vocal cord dysfunction. Chronic lung diseases such as asthma, COPD, and interstitial lung disease impact exercise capacity and endurance. Exercise testing can be useful to distinguish acute and chronic pulmonary causes of dyspnea during exercise, as well as to differentiate between cardiac and pulmonary causes.
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Affiliation(s)
- Jonathon Truwit
- University of Virginia Health System, P.O. Box 800546, Charlottesville, VA 22908, USA.
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Abstract
Measurement of DL(CO) remains a clinically useful way to assess transfer of gases across the lung. It is important, however, to be vigilant in controlling the sources of variation and to be aware of those that remain when interpreting the measured values.
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Affiliation(s)
- R O Crapo
- University of Utah School of Medicine, Pulmonary Division, LDS Hospital, Salt Lake City, USA.
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Stewart IB, Potts JE, McKenzie DC, Coutts KD. Effect of body position on measurements of diffusion capacity after exercise. Br J Sports Med 2000; 34:440-4. [PMID: 11131232 PMCID: PMC1724252 DOI: 10.1136/bjsm.34.6.440] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Pulmonary diffusing capacity for carbon monoxide (D1co), alveolar capillary membrane diffusing capacity (Dm), and pulmonary capillary blood volume (Vc) are all significantly reduced after exercise. OBJECTIVE To investigate whether measurement position affects this impaired gas transfer. METHODS Before and one, two, and four hours after incremental cycle ergometer exercise to fatigue, single breath D1co, Dm, and Vc measurements were obtained in 10 healthy men in a randomly assigned supine and upright seated position. RESULTS After exercise, D1co, Dm, and Vc were significantly depressed compared with baseline in both positions. The supine position produced significantly higher values over time for D1co (5.22 (0.13) v. 4.66 (0.15) ml/min/mm Hg/l, p = 0.022) and Dm (6.78 (0.19) v. 6.03 (0.19) ml/min/mm Hg/l, p = 0.016), but there was no significant position effect for Vc. There was a similar pattern of change over time for D1co, Dm, and Vc in the two positions. CONCLUSIONS The change in D1co after exercise appears to be primarily due to a decrease in Vc. Although the mechanism for the reduction in Vc cannot be determined from these data, passive relocation of blood to the periphery as the result of gravity can be discounted, suggesting that active vasoconstriction of the pulmonary vasculature and/or peripheral vasodilatation is occurring after exercise.
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Affiliation(s)
- I B Stewart
- University of British Columbia, Allan McGavin Sports Medicine Center, Vancouver, Columbia, Canada.
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Abstract
During exercise, healthy individuals are able to maintain arterial oxygenation, whereas highly-trained endurance athletes may exhibit an exercise-induced arterial hypoxaemia (EIAH) that seems to reflect a gas exchange abnormality. The effects of EIAH are currently debated, and different hypotheses have been proposed to explain its pathophysiology. For moderate exercise, it appears that a relative hypoventilation induced by endurance training is involved. For high-intensity exercise, ventilation/perfusion (V(A)/Q) mismatching and/or diffusion limitation are thought to occur. The causes of this diffusion limitation are still under debate, with hypotheses being capillary blood volume changes and interstitial pulmonary oedema. Moreover, histamine is released during exercise in individuals exhibiting EIAH, and questions persist as to its relationship with EIAH and its contribution to interstitial pulmonary oedema. Further investigations are needed to better understand the mechanisms involved and to determine the long term consequences of repetitive hypoxaemia in highly trained endurance athletes.
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Affiliation(s)
- C Prefaut
- Clinical Physiology Department, Hôpital Arnaud de Villeneuve, Montpellier, France.
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McKenzie DC, Lama IL, Potts JE, Sheel AW, Coutts KD. The effect of repeat exercise on pulmonary diffusing capacity and EIH in trained athletes. Med Sci Sports Exerc 1999; 31:99-104. [PMID: 9927016 DOI: 10.1097/00005768-199901000-00016] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The purpose of this study was to determine the effects of repeated heavy exercise on postexercise pulmonary diffusing capacity (DL) and the development of exercise induced arterial hypoxemia (EIH). METHODS 13 endurance-trained, male athletes (age = 27+/-3 yr, height = 179.6+/-5.0 cm, weight = 71.8+/-6.9 kg, VO2max = 67.0+/-3.6 mL x kg(-1) x min(-1) performed two consecutive, continuous exercise tests on a cycle ergometer to VO2max, separated by 60 min of recovery. Arterial oxygen saturation (%SaO2) was measured via ear oximetry, and resting DL was measured and partitioned by the single-breath method, before exercise and 60 min after each exercise bout. RESULTS No significant differences resulted in VO2max, VE, peak heart rate (HR), or breathing frequency between exercise bouts (P > 0.05). There was a small but significant decrease (454-446 W; P < 0.05) in peak power output in the second test. %SaO2 decreased from resting values during both exercise tasks, but there was no difference between the minimum saturation achieved in test 1 (91.4) or test 2 (91.6; P > 0.05). After the initial exercise bout, significant decreases (P < 0.05) occurred in DL (11%), membrane diffusing capacity (DM) (11%) and pulmonary capillary volume (VC) (10%). Further decreases occurred in DL (6%; P < 0.05), DM (2%; P > 0.05), and VC (10%; P < 0.05) after the second exercise bout. CONCLUSIONS These observations question the meaning of post exercise measurements of pulmonary diffusion capacity, and its components, relative to pulmonary gas exchange and pulmonary fluid accumulation during exercise. The fact that there was no further change in %SaO2 after the second test suggests that if any interstitial edema developed, it was of no clinical significance; alternatively, the changes in DL(CO) may be related more to redistribution of blood than the development of pulmonary edema.
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Affiliation(s)
- D C McKenzie
- Allan McGavin Sports Medicine Centre and the School of Human Kinetics, The University of British Columbia, Vancouver, Canada.
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