Estudio de la difusión pulmonar durante el ejercicio en condiciones extremas

[spa] La siguiente tesis doctoral tiene como objetivo principal estudiar la respuesta de la difusión pulmonar en la barrera alveolocapilar durante diferentes condiciones extremas relacionados con el entrenamiento de natación y el ejercicio en altitud. De esta forma, se describirán los siguientes objetivos específicos: 1. Evaluar posibles cambios en la difusión pulmonar (DLCO y KCO) y otros parámetros respiratorios (VA, TLC, VCIN y RV) durante el entrenamiento (pre- vs. post-) en natación y natación artística, además de valorar su posible relevancia clínica. o Describir los parámetros de capacidad pulmonar y de difusión en deportistas acuáticos. 2. Valorar el impacto de una concentración de entrenamiento en altitud a 1.850 m en los parámetros de capacidad pulmonar y difusión de un grupo de nadadores de elite. o Evaluar posibles cambios en la difusión pulmonar después de una sesión de ciclismo a intensidad moderada a 3.000 m de hipoxia normobárica. 3. Comparar la respuesta de difusión pulmonar en un grupo de nadadores de elite vs. un grupo de sujetos sanos durante una exposición aguda a 4.000 m simulados de hipoxia hipobárica y después de un ejercicio de intensidad moderada a dicha altitud.[eng] Lung diffusing capacity describes the alveolar-capillary diffusion in the lungs, which increase linearly in relation to cardiac output, and decrease in the presence of lung interstitial disease. This thesis aimed to study whether aquatic exercise (swimming and artistic swimming) provoke a decrease in lung diffusing capacity for carbon monoxide (DLCO) during training; and whether altitude training camp or exercise in a short-term exposure to high-altitude modify lung diffusing capacity in elite swimmers. The first article describes the initial justification of this research. In this report case, we describe the circumstance faced by a female elite swimmers who had repeated dyspnoea associated to the intensity of the swimming exercise. She experimented a post-exercise reduction in spirometric values and the presence of ultrasound lung comets (ULCs), suggesting a swimming-induced pulmonary oedema (SIPO). The report case conclude that the administration of an inhibitor of the carbonic anhydrase (Acetazolamide) solved this condition. The second and third article form two parts of the same research. We conducted a follow-up during 10 swimming training session in 21 elite junior swimmers evaluating the DLCO pre- and post-training. We show a slight decrease in lung diffusing capacity (−2.5%) after training, showing that swimmers experience subclinical decrease in lung diffusing capacity. Also, there were a large inter-individual variability in the response of DLCO to swim training along the follow-up including 6 subjects showing a considerable average decrease (−5.6–11.2%), suggesting that, doctors and coaches should pay attention to the individual changes in alveolar-capillary diffusing capacity among elite swimmers. The fourth article describes the changes in DLCO during an artistic swimming session in 11 artistic swimmers. After the first part of the training (apnoeic swimming) there were an increase in lung diffusing capacity (+9.2%) and later, after the second part (choreography and figures) there were a decrease in lung diffusing capacity regarding to basal condition (−4.0%). Therefore, it could be interesting to monitor carefully individual response to exercise since there occur decreases in DLCO up to 20% after training. The fifth article studies the possible modifications in lung diffusing capacity during a 14-day swimming altitude training camp at 1,850 m. There were no changes in DLCO after the training camp, but a decrease in alveolar volume (VA) and an increase in transfer coefficient of the lung for carbon monoxide (KCO) occur. In contrast to the results found at sea level in the second and third article, a swimming training session in moderate altitude did not change lung diffusing capacity acutely in elite swimmers, but a posterior cycling session at normobaric-simulated 3,000 m reduced DLCO significantly (−10%). The sixth article reports the lung diffusing response to 30-min moderate intensity interval exercise in a short-term exposure to high-altitude (4,000 m) in elite swimmers. There were no changes in DLCO although elite swimmers showed large decrease in SpO2 (72 ± 5 %) and a large increase in HR (139 ± 9 beats·min-1) at the end of the exercise. The seventh article evaluates whether there are changes in alveolar-capillary diffusion after different modalities of exercise, both at sea level (SL) and high-altitude (HA) in 11 healthy subjects. At SL, lung diffusing capacity largely increased after 30-s maximal exercise in a cycle ergometer, although the O2-dependence was small during anaerobic exercise. In contrast, DLCO did not change after 15-min moderate intensity continuous exercise at SL. Later, at HA, and similar to the previous study, an acute protocol of exercise at HA did not modify lung diffusing capacity in healthy subjects, suggesting that short-term exercise modalities at high-altitude are well covered by the functional properties of healthy individuals’ lungs. Lastly, the eighth article describes the pulmonary functional capabilities in elite swimmers, artistic swimmers and water polo players, showing higher lung volumes and diffusing capacity than the reference values by height and age. In this article, we discuss that swimming-based sports could be beneficial to improve the pulmonary function in many different segments of the population (from subjects with chronic pathologies to elite athletes) due to the physical properties of the water and physiological implications of the practice of swimming

Changes in lung diffusing capacity of elite artistic swimmers during training

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·mmHg; 139 ± 19%) and there were a significant interaction between DLCO and AS training (ŋ2p = 0.547). After the apnoeic swimming (mid-training) there was an increase in DLCO from basal to 36.7 ± 7.3 mL/min·mmHg (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·mmHg, 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

Lung diffusion in a 14-day swimming altitude training camp at 1850 meters

Swimming exercise at sea level causes a transient decrease in lung diffusing capacity for carbon monoxide (DLCO). The exposure to hypobaric hypoxia can affect lung gas exchange, and hypoxic pulmonary vasoconstriction may elicit pulmonary oedema. The purpose of this study is to evaluate whether there are changes in DLCO during a 14-day altitude training camp (1850 m) in elite swimmers and the acute effects of a combined training session of swimming in moderate hypoxia and 44-min cycling in acute normobaric severe hypoxia (3000 m). Participants were eight international level swimmers (5 females and 3 males; 17-24 years old; 173.5 ± 5.5 cm; 64.4 ± 5.3 kg) with a training volume of 80 km per week. The single-breath method was used to measure the changes in DLCO and functional gas exchange parameters. No changes in DLCO after a 14-day altitude training camp at 1850 m were detected but a decrease in alveolar volume (VA; 7.13 ± 1.61 vs. 6.50 ± 1.59 L; p = 0.005; d = 0.396) and an increase in the transfer coefficient of the lung for carbon monoxide (KCO; 6.23 ± 1.03 vs. 6.83 ± 1.31 mL·min−1·mmHg−1·L−1; p = 0.038; d = 0.509) after the altitude camp were observed. During the acute hypoxia combined session, there were no changes in DLCO after swimming training at 1850 m, but there was a decrease in DLCO after cycling at a simulated altitude of 3000 m (40.6 ± 10.8 vs. 36.8 ± 11.2 mL·min−1·mmHg−1; p = 0.044; d = 0.341). A training camp at moderate altitude did not alter pulmonary diffusing capacity in elite swimmers, although a cycling session at a higher simulated altitude caused a certain degree of impairment of the alveolar-capillary gas exchange

Severe hypoxic exercise does not impair lung diffusion in elite swimmers

Background: Exercise performed at high-altitude may cause a sub-clinical pulmonary interstitial edema which can worsen gas exchange function. This study aimed to evaluate whether there are changes in alveolar-capillary diffusion after exercise during a short-term exposure to hypobaric hypoxia in elite swimmers. Materials & Methods: Seven elite swimmers [age: 20.4 ± 1.4 years, height: 1.78 ± 10.8 m, body mass (BM): 69.7 ± 11.1 kg] participated in the study. Diffusing capacity of the lungs for carbon monoxide (DLCO), transfer coefficient of carbon monoxide (KCO), pulse oximeter oxygen saturation (SpO2) and heart rate (HR) were measured at sea level at rest (SL-R), and after a short-term hypobaric hypoxia exposure (4,000 m), both at rest (HA-R) and at the end of moderate interval exercise (HA-E). Results: The combined exposure to high-altitude and exercise did not change DLCO from SL-R to HA-R, or HA-E (43.8 ± 9.8 to 41.3 ± 10.5 to 42.4 ± 8.6 ml·min-1·mmHg-1, P = 0.391). As expected, elite swimmers showed large decrease in SpO2 (72 ± 5; P < 0.001) and increase in HR (139 ± 9 beats·min-1; P < 0.003) after HA-E. Conclusions: An acute high-altitude exposure combined with submaximal exercise does not change alveolar-capillary diffusion in elite swimmers

Lung capacity and alveolar gas diffusion in aquatic athletes: Implications for performance and health

Background: The diffusion capacity of carbon monoxide (DLCO) provides a measure of gas transfer in the lungs. Endurance training does not increase lung volumes and diffusion in land-based athletes. However swimmers have larger lungs and better diffusion capacity than other matched athletes and controls. Purpose: The aim of this study is to evaluate pulmonary alveoli-capillary diffusion and lung volumes in elite aquatic athletes, specifically: swimmers, artistic swimmers and water polo players. Methods: The participants were 64 international level aquatic athletes including 31 swimmers (11 female and 20 male), 12 artistic swimmers (only female), and 21 water polo players (10 female and 11 male). The single-breath method was used to measure DLCO and pulmonary parameters. Results: The main finding of this study is that DLCO is high, in aquatic athletes, clearly above their reference values, both in females (33.4 ± 9.4 mL·min-1·mmHg-1; 135%) and males (48.0 ± 5.83 mL·min-1·mmHg-1; 148%). There was no different DLCO between groups in female swimmers, artistic swimmers and water polo players (34.7 ± 8.3 to 33.4 ± 4.0 to 32.1 ± 5.6 mL·min-1·mmHg-1), but male swimmers had higher DLCO compared to water polo players (50.4 ± 5.3 to 43.4 ± 7.0, p = 0.014). Conclusions: Aquatic athletes have larger lungs and better diffusion capacity than the percentage predicted by age and height. Therefore, swimming-based sports could be beneficial to improve the pulmonary function in many different segments of the population

Swimming exercise for patients with long-term respiratory post COVID-19 complications: Further thinking on the pulmonary rehabilitation

Swimming is an aquatic sport in which the propulsion is coordinated with respiratory phases, consisting in underwater apnoeas interspersed with rapid and deep inhalations out of the water. This breathing pattern provokes those aquatic athletes have higher lung volumes and lung diffusing capacities than other athletes and general population