Influence of Performance Level on Exercise-Induced Arterial Hypoxemia During Prolonged and Successive Exercise in Triathletes

2008 ◽  
Vol 3 (4) ◽  
pp. 482-500 ◽  
Author(s):  
Olivier Galy ◽  
Olivier Hue ◽  
Karim Chamari ◽  
Alain Boussana ◽  
Anis Chaouachi ◽  
...  
Keyword(s):  
Short Distance ◽  
Alveolar Ventilation ◽  
Diffusing Capacity ◽  
Diffusion Limitation ◽  
Arterial Hypoxemia ◽  
Ventilatory Parameters ◽  
Before And After ◽  
Exercise Induced ◽  
And Control ◽  
The Relationship

Purpose:To study the relationship between performance and exercise-induced arterial hypoxemia (EIAH), 5 internationally ranked (INT) and 8 regionally ranked (REG) triathletes performed cycle-run successions (CR) and control runs (R) in competitionlike conditions: at ≍75% VO2max.Methods:Ventilatory parameters and oxyhemoglo-bin saturation (SpO2) data were collected continuously. Arteriolized partial pressure in O2 (PaO2) and alveolar ventilation (VA) were measured before and after cycling (CRcycle), the successive run (CRrun), and R. Pulmonary diffusing capacity (DLco) was measured at rest and 10 minutes post-CR. Training and short-distance triathlon data were collected.Results:INT showed signifcantly greater experience than REG in competition years (P > .05), training regimen (P > .05), and swimming (P > .05), and cycling (P > .05) volumes; running showed a trend (P < .06). Cycling, running, and total triathlon performances were significantly higher in INT than REG (P > .01). SpO2 during CR dropped significantly more in INT than in REG. Both groups showed significant inverse correlations between the magnitude of the SpO2 change from CRcy-cle to CRrun and the triathlon running time (r = −0.784; P < .05 and r = −0.699; P < .05; respectively). When compared with CRcycle, PaO2 significantly decreased and VA significantly increased after CRrun and R in both groups (P < .01). DLco significantly dropped between pre- and postexercise in CR and R with no between-group difference (P < .05).Conclusions:EIAH was aggravated in higher performers during simulated cycle-run segments, related to longer experience and heavier training regimens. Possibly, relative hypoventilation caused this aggravated EIAH in INT, although pulmonary diffusion limitation was observed in both groups. Beyond EIAH severity, the magnitude of SpO2 variations during the cycle-run transition may affect triathlon running performance.

scholarly journals Pulmonary gas exchange during exercise in highly trained cyclists with arterial hypoxemia

1999 ◽  
Vol 87 (5) ◽  
pp. 1802-1812 ◽  
Author(s):  
Anthony J. Rice ◽  
Andrew T. Thornton ◽  
Christopher J. Gore ◽  
Garry C. Scroop ◽  
Hugh W. Greville ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Maximal Exercise ◽  
Inert Gas ◽  
Diffusing Capacity ◽  
Stepwise Multiple Linear Regression ◽  
Diffusion Limitation ◽  
Arterial Hypoxemia ◽  
Exercise Induced

The causes of exercise-induced hypoxemia (EIH) remain unclear. We studied the mechanisms of EIH in highly trained cyclists. Five subjects had no significant change from resting arterial[Formula: see text]([Formula: see text]; 92.1 ± 2.6 Torr) during maximal exercise (C), and seven subjects (E) had a >10-Torr reduction in [Formula: see text] (81.7 ± 4.5 Torr). Later, they were studied at rest and during various exercise intensities by using the multiple inert gas elimination technique in normoxia and hypoxia (13.2% O2). During normoxia at 90% peak O2 consumption,[Formula: see text] was lower in E compared with C (87 ± 4 vs. 97 ± 6 Torr, P < 0.001) and alveolar-to-arterial O2tension difference (a-[Formula: see text]) was greater (33 ± 4 vs. 23 ± 1 Torr, P < 0.001). Diffusion limitation accounted for 23 (E) and 13 Torr (C) of thea-[Formula: see text]( P < 0.01). There were no significant differences between groups in arterial[Formula: see text]([Formula: see text]) or ventilation-perfusion (V˙a/Q˙) inequality as measured by the log SD of the perfusion distribution (logSDQ˙). Stepwise multiple linear regression revealed that lung O2 diffusing capacity ([Formula: see text]), logSDQ˙, and[Formula: see text] each accounted for ∼30% of the variance in [Formula: see text]( r = 0.95, P < 0.001). These data suggest that EIH has a multifactorial etiology related to[Formula: see text],V˙a/Q˙inequality, and ventilation.

scholarly journals Contribution of BKCa channels to local metabolic coronary vasodilation: effects of metabolic syndrome

2010 ◽  
Vol 298 (3) ◽  
pp. H966-H973 ◽  
Author(s):  
Léna Borbouse ◽  
Gregory M. Dick ◽  
Gregory A. Payne ◽  
Brittany D. Payne ◽  
Mark C. Svendsen ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Metabolic Syndrome ◽  
Heart Rate ◽  
Atherogenic Diet ◽  
Bkca Channels ◽  
Selective Blockade ◽  
Before And After ◽  
Lactate Uptake ◽  
Exercise Induced ◽  
The Relationship

This investigation was designed to examine the hypothesis that impaired function of coronary microvascular large-conductance Ca2+-activated K+ (BKCa) channels in metabolic syndrome (MetS) significantly attenuates the balance between myocardial oxygen delivery and metabolism at rest and during exercise-induced increases in myocardial oxygen consumption (MV̇o2). Studies were conducted in conscious, chronically instrumented Ossabaw swine fed a normal maintenance diet (11% kcal from fat) or an excess calorie atherogenic diet (43% kcal from fat, 2% cholesterol, 20% kcal from fructose) that induces many common features of MetS. Data were collected under baseline/resting conditions and during graded treadmill exercise before and after selective blockade of BKCa channels with penitrem A (10 μg/kg iv). We found that the exercise-induced increases in blood pressure were significantly elevated in MetS swine. No differences in baseline cardiac function or heart rate were noted. Induction of MetS produced a parallel downward shift in the relationship between coronary venous Po2 and MV̇o2 ( P < 0.001) that was accompanied by a marked release of lactate (negative lactate uptake) as MV̇o2 was increased with exercise ( P < 0.005). Inhibition of BKCa channels with penitrem A did not significantly affect blood pressure, heart rate, or the relationship between coronary venous Po2 and MV̇o2 in lean or MetS swine. These data indicate that BKCa channels are not required for local metabolic control of coronary blood flow under physiological (lean) or pathophysiological (MetS) conditions. Therefore, diminished function of BKCa channels does not contribute to the impairment of myocardial oxygen-supply demand balance in MetS.

Splenectomy impairs diffusive oxygen transport in the lung of dogs

2006 ◽  
Vol 101 (1) ◽  
pp. 289-297 ◽  
Author(s):  
D. Merrill Dane ◽  
Connie C. W. Hsia ◽  
Eugene Y. Wu ◽  
Richard T. Hogg ◽  
Deborah C. Hogg ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Volume ◽  
Pulmonary Blood Flow ◽  
Compensatory Mechanism ◽  
Diffusing Capacity ◽  
Restrictive Lung Disease ◽  
Before And After ◽  
Capillary Blood Volume ◽  
Exercise Induced ◽  
Experimental Findings

The spleen acts as an erythrocyte reservoir in highly aerobic species such as the dog and horse. Sympathetic-mediated splenic contraction during exercise reversibly enhances convective O2 transport by increasing hematocrit, blood volume, and O2-carrying capacity. Based on theoretical interactions between erythrocytes and capillary membrane (Hsia CCW, Johnson RL Jr, and Shah D. J Appl Physiol 86: 1460–1467, 1999) and experimental findings in horses of a postsplenectomy reduction in peripheral O2-diffusing capacity (Wagner PD, Erickson BK, Kubo K, Hiraga A, Kai M, Yamaya Y, Richardson R, and Seaman J. Equine Vet J 18, Suppl: 82–89, 1995), we hypothesized that splenic contraction also augments diffusive O2 transport in the lung. Therefore, we have measured lung diffusing capacity (DlCO) and its components during exercise by a rebreathing technique in six adult foxhounds before and after splenectomy. Splenectomy eliminated exercise-induced polycythemia, associated with a 30% reduction in maximal O2 uptake. At any given pulmonary blood flow, DlCO was significantly lower after splenectomy owing to a lower membrane diffusing capacity, whereas pulmonary capillary blood volume changed variably; microvascular recruitment, indicated by the slope of the increase in DlCO with respect to pulmonary blood flow, was also reduced. We conclude that splenic contraction enhances both convective and diffusive O2 transport and provides another compensatory mechanism for maintaining alveolar O2 transport in the presence of restrictive lung disease or ambient hypoxia.

Effect of sex on perception of rectosigmoid stimuli in irritable bowel syndrome

2006 ◽  
Vol 291 (2) ◽  
pp. R277-R284 ◽  
Author(s):  
Lin Chang ◽  
Emeran A. Mayer ◽  
Jennifer S. Labus ◽  
Max Schmulson ◽  
Oh Young Lee ◽  
...  
Keyword(s):  
Irritable Bowel Syndrome ◽  
Sigmoid Colon ◽  
Healthy Controls ◽  
Perceptual Sensitivity ◽  
Control Groups ◽  
Healthy Men ◽  
Before And After ◽  
Irritable Bowel ◽  
And Control ◽  
The Relationship

In irritable bowel syndrome (IBS) patients, the relationship between sex and sensitivity to visceral stimuli is incompletely understood. Our aim was to evaluate the effect of sex on perceptual responses to visceral stimulation in IBS. Fifty-eight IBS patients (mean age 42 ± 1 yr; 34 men, 24 women) and 26 healthy controls (mean age 38 ± 3 yr; 9 men, 17 women) underwent barostat-assisted distensions of the rectum and sigmoid colon. Rectal discomfort thresholds were measured using a randomized, phasic distension paradigm before and after repeated noxious sigmoid stimulation (SIG, 60-mmHg pulses). Sex had a significant effect on rectal discomfort thresholds. Women with IBS were the most sensitive (lower thresholds [27 ± 2.7 mmHg] and higher ratings), with significantly lower rectal discomfort thresholds compared with men with IBS (38 ± 2.3 mmHg) and healthy women who were the least sensitive (41.9 ± 3.2 mmHg; both P < 0.01). There were no significant differences in rectal discomfort thresholds between healthy men (34 ± 4.3 mmHg) and men with IBS. Across both IBS and control groups, women demonstrated a significant lowering of discomfort thresholds after noxious sigmoid stimulation ( P < 0.01), while men did not. Sex significantly influences perceptual sensitivity to rectosigmoid distension. Women show greater perceptual responses to this paradigm.

Intramuscular substrate depletion and fatigability of soleus grafts in rats

1988 ◽  
Vol 66 (6) ◽  
pp. 829-832 ◽  
Author(s):  
Claude Côté ◽  
Timothy P. White ◽  
John A. Faulkner
Keyword(s):  
Oxidative Capacity ◽  
Contractile Properties ◽  
Fatigue Protocol ◽  
Triglyceride Concentration ◽  
Before And After ◽  
And Control ◽  
The Relationship

We investigated the relationship between oxidative capacity, substrate depletion, and fatigability of muscle grafts in situ. Isometric contractile properties and fatigability were measured in stabilized grafts and control muscles from age-matched rats. Intramuscular glycogen and triglyceride concentrations were measured before and after the fatigue protocol. Even though stabilized soleus grafts have a reduced oxidative capacity compared with control soleus muscles, no difference was observed between groups in terms of resistance to fatigue. Glycogen concentrations did not decrease significantly during the fatigue protocol in either group. Compared with control muscles, the triglyceride concentration in the grafts was significantly higher before the fatigue protocol and it decreased significantly more following the fatigue protocol.

scholarly journals Saúde on-line: impacto na prevalência de obesidade e satisfação corporal de adolescentes

2018 ◽  
Vol 12 (2) ◽  
pp. 312
Author(s):  
Régis Jhonatan Morais Gonçalves ◽  
Ramon Azevedo Silva Castro ◽  
Vinícius Silva Belo ◽  
Luana Santos Vital Alves Coelho ◽  
Erika Barbosa Lagares ◽  
...  
Keyword(s):  
Body Image ◽  
Health Education ◽  
Body Dissatisfaction ◽  
Body Satisfaction ◽  
Obese Female ◽  
Health Education Intervention ◽  
Before And After ◽  
On Line ◽  
And Control ◽  
The Relationship

RESUMOObjetivo: avaliar o efeito de ação de educação em saúde, conduzida pelo Facebook, na prevalência de sobrepeso/obesidade e na satisfação corporal de adolescentes, bem como a relação de concordância entre estas medidas e as diferenças em adolescentes. Método: estudo quantitativo, ensaio não controlado, em que 69 adolescentes de ambos os sexos, dos 13 aos 19 anos, foram avaliados em 4 meses quanto ao estado nutricional e percepção corporal, antes e depois de intervenção de educação em saúde sobre nutrição. Resultados: 20,8% estavam com excesso de peso, 20,3% se percebiam com excesso de peso e 36,2% apresentavam insatisfação corporal. Houve maior prevalência de insatisfação corporal entre adolescentes do sexo feminino com sobrepeso/obesidade. Conclusão: não se evidenciou impacto estatisticamente significativo da estratégia de educação em saúde executada na prevalência de sobrepeso/obesidade e na satisfação com a imagem corporal. Discutem-se os fatores associados com o baixo impacto da intervenção e a importância de estudos dessa natureza, visto que a obesidade é multideterminada, o que implica a necessidade de que abordagens utilizadas para a prevenção e o controle desse agravo sejam avaliadas quanto a seus sucessos e insucessos para que sejam aprimoradas em estudos futuros. Descritores: Adolescente; Antropometria; Imagem corporal; Rede social; Educação em saúde; Obesidade.ABSTRACT Objective: to evaluate the effect of a health education action, conducted by Facebook, on the prevalence of overweight/obesity and adolescent body satisfaction, as well as the relationship between these measures and differences among adolescents. Method: quantitative study, uncontrolled trial, in which 69 adolescents of both sexes, from 13 to 19 years old, were evaluated in four months regarding nutritional status and body perception, before and after health education intervention on nutrition. Results: 20.8% were overweight, 20.3% perceived as overweight and 36.2% presented body dissatisfaction. There was a higher prevalence of body dissatisfaction among overweight / obese female adolescents. Conclusion: there was no statistically significant impact of the health education strategy, implemented in the prevalence of overweight/obesity and satisfaction with body image. The factors associated with the low impact of the intervention and the importance of studies of this nature were discussed, since obesity is multidetermined, which implies that the approaches used for the prevention and control of this condition should be evaluated for their successes and failures to be improved in future studies. Descriptors: Adolescent; Anthropometry; Body Image; Social Networking; Health Education; Obesity.RESUMEN Objetivo: evaluar el efecto de acción de educación en salud conducida por el Facebook en la prevalencia de sobrepeso / obesidad y en la satisfacción corporal de adolescentes, así como la relación de concordancia entre estas medidas y las diferencias en adolescentes. Método: el estudio cuantitativo, ensayo no controlado, en el que 69 adolescentes de ambos sexos, de 13 a 19 años, fueron evaluados en 4 meses en cuanto al estado nutricional y percepción corporal, antes y después de intervención de educación en salud sobre nutrición. Resultados: 20,8% estaban con exceso de peso, el 20,3% se percibía con exceso de peso y el 36,2% presentaba insatisfacción corporal. Hubo mayor prevalencia de insatisfacción corporal entre adolescentes con sobrepeso / obesidad. Conclusión: no se evidenció impacto estadísticamente significativo de la estrategia de educación en salud ejecutada en la prevalencia de sobrepeso / obesidad y en la satisfacción con la imagen corporal. Se discuten los factores asociados con el bajo impacto de la intervención y la importancia de estudios de esa naturaleza, ya que la obesidad es multideterminada, lo que implica la necesidad de que enfoques utilizados para la prevención y control de ese agravamiento sean evaluados en cuanto a sus éxitos y fracasos para que se perfeccionen en estudios futuros. Descriptores: Adolescente; Antropometría; Imagem Corporal; Red Social; Educación em Salud; Obesidad.

scholarly journals Effect of training on the development of exercise-induced arterial hypoxemia in volleyball players

2020 ◽  
Vol 24 (6) ◽  
pp. 312-318
Author(s):  
Selcen Korkmaz Eryılmaz ◽  
Kerimhan Kaynak
Keyword(s):  
Minute Ventilation ◽  
Training Period ◽  
Oxyhemoglobin Saturation ◽  
Arterial Hypoxemia ◽  
Ventilatory Equivalent ◽  
Significant Difference ◽  
Volleyball Players ◽  
Before And After ◽  
History Of ◽  
Exercise Induced

Background and Study Aim. The purpose of this study was to examine the effect of volleyball training on the development of exercise-induced arterial hypoxemia during incremental exercise in male competitive volleyball players. Material and Methods.  Eight male amateur volleyball players (age 21±1.3 years) participated in a 6-week volleyball training program three times a week in the pre-season preparatory period. Before and after the training period, all players performed an incremental treadmill test to determine maximal oxygen uptake (VO2max), and oxyhemoglobin saturation (SaO2) was continuously measured using a pulse oximeter during the test. Maximal values of minute ventilation (VEmax), respiratory exchange ratio (RERmax), ventilatory equivalent for oxygen (VE/VO2) and carbon dioxide (VE/VCO2) were determined. Exercise-induced arterial hypoxemia (EIAH) was defined as a SaO2 decreased by at least 4% (ΔSaO2≤ −4%) from resting level. Results. All the players exhibited exercise-induced arterial hypoxemia before (ΔSaO2= –8.8±3.3%) and after (ΔSaO2= –8.31.5%) the training period. SaO2 was significantly decreased from 97.6±1% at rest to 88.7±2.7% at exhaustion before the training period, and from 97.2±1.1% at rest to 88.8±2.1% at exhaustion after training period (p < 0.001). There was no significant difference in resting and lowest SaO2 values by comparison between the before and after training (p > 0.05). There were no significant changes in VO2max, VEmax, RERmax, VE/VO2 and VE/VCO2 after training period (p > 0.05). Conclusions. The results of this study showed that volleyball players with a history of anaerobic training may exhibit EIAH, but that 6-week volleyball training has no effect on the degree of exercise-induced arterial hypoxemia.

scholarly journals Exercise-induced modulation of gut microbiota in rats with metabolic syndromes

2015 ◽  
Author(s):  
Alinne Castro ◽  
Bernardo A Petriz
Keyword(s):  
Exercise Training ◽  
Gut Microbiota ◽  
Rrna Gene ◽  
Spontaneously Hypertensive ◽  
Obesity And Diabetes ◽  
Central Hypothesis ◽  
Before And After ◽  
Exercise Induced ◽  
The Relationship

Obesity and diabetes mellitus are multifactor diseases associated to cardiovascular disorders that affect huge proportion of our society. Growing evidence suggests that gut microbes contribute to several pathological conditions as well as the exercise is a well-known agent used for numerous pathologies treatments, such as obesity and hypertension. As only a small fraction of the bacterial communities present in the gut can be in vitro cultured, barcode 16S rRNA gene pyrosequencing from fecal samples collected before and after exercise training was used for to access the relationship between controlled exercise training and gut microbiota composition in the obese (OB), non-obese rats (WISTAR) and spontaneously hypertensive rats (SHR). The central hypothesis of this study was that controlled exercise would lead to significant changes in the composition of gut microbial communities.

CO2 diffusing capacity in isolated dog lung lobes and the role of carbonic anhydrase

1983 ◽  
Vol 54 (2) ◽  
pp. 483-490 ◽  
Author(s):  
T. Enns ◽  
E. P. Hill
Keyword(s):  
Carbonic Anhydrase ◽  
Lung Tissue ◽  
Co2 Flux ◽  
Diffusing Capacity ◽  
Diffusion Limitation ◽  
Molecular Weights ◽  
Before And After ◽  
Alveolar Capillary ◽  
Lung Lobes

CO2 diffusing capacities (DmCO2) were measured at 22 degrees C on 12 isolated perfused dog lung lobes before and after inhibition of lung tissue carbonic anhydrase (CA) by acetazolamide (Diamox). The hypothesis is that CA in the alveolar-capillary tissue enhances overall transport of CO2 by converting CO2 to HCO-3 within aqueous portions of the tissue. HCO-3 diffuses simultaneously with molecular CO2, increasing the overall CO2 flux, and then converts back to molecular CO2 at the end of the aqueous pathway. To ensure at least partial diffusion limitation, lobes were perfused with phosphate buffer at high pH (7.7) and high flow rates. Plant CA (which is not inhibited significantly by Diamox) was added to the perfusate to provide rapid uptake of CO2 via conversion to HCO-3. After Diamox, DCO2 decreased 39.6%, indicating that CA does increase CO2 transport through lung tissue. Surprisingly, DCO2 exceeds CO diffusing capacity by only 9.3 +/- 2.1 times (without Diamox inhibition) rather than by the factor of 24 predicted by Graham's law on the basis of solubilities and molecular weights of the gases.

scholarly journals Microdialysis for chronic exertional compartment syndrome: a pilot study

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Heinz Lohrer ◽  
Jochen Klein ◽  
Tanja Nauck ◽  
Tobias Schönberg
Keyword(s):  
Pilot Study ◽  
Compartment Syndrome ◽  
Level Of Evidence ◽  
Chronic Exertional Compartment Syndrome ◽  
Control Subjects ◽  
Exertional Compartment Syndrome ◽  
Before And After ◽  
Healthy Control ◽  
Exercise Induced ◽  
And Control

Abstract Background Diagnosing chronic exertional compartment syndrome (CECS) is still a challenge. An increase in intramuscular pressure during and following exercise is accepted as the diagnostic standard. However, neither the methods used nor the interpretation of the obtained results are sufficiently standardized. Methods In the present pilot study, the metabolic state of CECS patients was investigated using microdialysis. We hypothesized that there was no difference in intramuscular concentrations of glucose, lactate, glutamate, and glycerol before and after exercise (H10) or between patients suffering from CECS and healthy control subjects (H20). This study was designed as an explorative case-control study (level of evidence III). Twelve patients suffering from CECS of the lower leg and six matched asymptomatic control subjects underwent microdialysis in the anterior (n = 7) or deep posterior compartment (n = 11) of the leg. Following ultrasound-guided insertion of the microdialysis catheters, 10-minute fractions of the dialysates were collected first during rest and then following fatigue- or pain-induced discontinuation of exercise. Dialysates were analysed for lactate, glucose, glutamate, and glycerol concentrations 6 × 10 min before and 6 × 10 min after exercise. Results Exercise-induced increases in lactate, glutamate, and glycerol concentrations were detected in both CECS patients and control subjects (all p < 0.001). No differences between CECS patients and control subjects were found by comparing the intramuscular glucose, lactate, glutamate, and glycerol concentrations at rest and following exercise (all p > 0.05). Conclusions We found exercise-induced increases in the lactate, glutamate, and glycerol levels in skeletal muscle. However, the metabolic changes did not differentiate CECS patients from healthy subjects. Trial registration The registration trial number is DRKS00021589 on DRKS. ‘Retrospectively registered’. Date of registration: April 4, 2020.

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