Altered tissue oxygenation in patients with post COVID-19 syndrome.

BACKGROUND: Post COVID-19 syndrome (PCS) is a complex condition with partly substantial impact on patients' social and professional life and overall life quality. Currently, the underlying cause(s) of PCS are unknown. Since PCS-specific symptoms could be associated with systemic alterations in tissue oxygen supply, we aimed to investigate changes in tissue oxygenation in patients with PCS. METHODS: A case-control study including 30 PCS patients (66.6 % males, 48.6 ± 11.2 years, mean time after (first) acute infection: 324 days), 16 cardiologic patients (CVD) (65.5 % males, 56.7 ± 6.3 years) and 11 young healthy controls (55 % males, 28.5 ± 7.4 years) was conducted. Near infrared spectroscopy (NIRS) was used to assess changes in tissue oxygenation during an arterial occlusion protocol on the non-dominant forearm (brachioradialis, 760/850 nm, 5 Hz). The protocol included 10-min rest, a 2-min baseline measurement followed by a 3-min ischemic period (upper-arm cuff, 50 mmHg above resting systolic blood pressure) and a 3-min reoxygenation period. PCS patients were grouped by presence of arterial hypertension and elevated BMI to assess the impact of risk factors. RESULTS: No differences in mean tissue oxygenation in the pre-occlusion phase existed between groups (p ≥ 0.566). During ischemia, comparisons of linear regressions slopes revealed slower oxygen desaturation for PCS patients (-0.064 %/s) compared to CVD patients (-0.08 %/s) and healthy subjects (-0.145 %/s) (p < 0.001). After cuff release, slowest speed for reoxygenation was detected in PCS patients at 0.84 %/s compared to CVD patients (1.04 %/s) and healthy controls (CG: 2.07 %/s) (p < 0.001). The differences between PCS patients and CVD patients during ischemia remained significant also after correction for risk factors. Analyses of complications during acute infection, persistence of PCS symptoms (time after acute infection), or PCS severity (number of lead symptoms) as confounding factors did not reveal a significant effect. CONCLUSIONS: This study provides evidence that the rate of tissue oxygen consumption is persistently altered in PCS and that PCS patients show an even slower decline in tissue oxygenation during occlusion than CVD patients. Our observations may at least partly explain PCS-specific symptoms such as physical impairment and fatigue.

Exercise intolerance associated with impaired oxygen extraction in patients with long COVID.

OBJECTIVE: Chronic mental and physical fatigue and post-exertional malaise are the more debilitating symptoms of long COVID-19. The study objective was to explore factors contributing to exercise intolerance in long COVID-19 to guide development of new therapies. Exercise capacity data of patients referred for a cardiopulmonary exercise test (CPET) and included in a COVID-19 Survivorship Registry at one urban health center were retrospectively analyzed. RESULTS: Most subjects did not meet normative criteria for a maximal test, consistent with suboptimal effort and early exercise termination. Mean O2 pulse peak % predicted (of 79 ± 12.9) was reduced, supporting impaired energy metabolism as a mechanism of exercise intolerance in long COVID, n = 59. We further identified blunted rise in heart rate peak during maximal CPET. Our preliminary analyses support therapies that optimize bioenergetics and improve oxygen utilization for treating long COVID-19.

Cardiopulmonary Exercise Testing in Post-COVID-19 Patients: Where Does Exercise Intolerance Come From? / Teste Cardiopulmonar em Pacientes Pós-COVID-19: De Onde vem a Intolerância ao Exercício?

BACKGROUND: Post-COVID-19 exercise intolerance is poorly understood. Cardiopulmonary exercise testing (CPET) can identify the underlying exercise limitations. OBJECTIVES: To evaluate the source and magnitude of exercise intolerance in post-COVID-19 subjects. METHODS: Cohort study assessing subjects with different COVID-19 illness severities and a control group selected by propensity score matching. In a selected sample with CPET prior to viral infection, before and after comparisons were performed. Level of significance was 5% in the entire analysis. RESULTS: One hundred forty-four subjects with COVID-19 were assessed (median age: 43.0 years, 57% male), with different illness severities (60% mild, 21% moderate, 19% severe). CPET was performed 11.5 (7.0, 21.2) weeks after disease onset, with exercise limitations being attributed to the peripheral muscle (92%), and the pulmonary (6%), and cardiovascular (2%) systems. Lower median percent-predicted peak oxygen uptake was observed in the severe subgroup (72.2%) as compared to the controls (91.6%). Oxygen uptake differed among illness severities and controls at peak and ventilatory thresholds. Conversely, ventilatory equivalents, oxygen uptake efficiency slope, and peak oxygen pulse were similar. Subgroup analysis of 42 subjects with prior CPET revealed significant reduction in only peak treadmill speed in the mild subgroup and in oxygen uptake at peak and ventilatory thresholds in the moderate/severe subgroup. By contrast, ventilatory equivalents, oxygen uptake efficiency slope, and peak oxygen pulse did not change significantly. CONCLUSIONS: Peripheral muscle fatigue was the most common exercise limitation etiology in post-COVID-19 patients regardless of the illness severity. Data suggest that treatment should emphasize comprehensive rehabilitation programs, including aerobic and muscle strengthening components.

FUNDAMENTO: A intolerância ao exercício pós-COVID-19 não é bem entendida. O teste de esforço cardiopulmonar (TECP) pode identificar as limitações ao exercício subjacentes. OBJETIVOS: Avaliar a etiologia e a magnitude da intolerância ao exercício em sujeitos pós-COVID-19. MÉTODOS: Estudo de coorte que avaliou sujeitos com níveis de gravidades diferentes da doença COVID-19 e um grupo de controle selecionado por pareamento por escores de propensão. Em uma amostra seleta com TECP anterior à infecção viral disponível, foram realizadas comparações antes e depois. O nível de significância foi de 5% em toda a análise. RESULTADOS: Foram avaliados cento e quarenta e dois sujeitos com COVID-19 (idade mediana: 43 anos, 57% do sexo masculino), com níveis de gravidade de doença diferentes (60% leve, 21% moderada, 19% grave). O TECP foi realizado 11,5 (7,0, 21,2) semanas após o aparecimento da doença, com as limitações ao exercício sendo atribuídas aos sistemas muscular periférico (92%), pulmonar (6%), e cardiovascular (2%). Menor valor mediano do consumo de oxigênio pico percentual foi observado no subgrupo com níveis graves de doença (72,2%) em comparação com os controles (91,6%). O consumo de oxigênio foi diferente entre os grupos com diferentes níveis de gravidade de doença e o controle no pico e nos limiares ventilatórios. Inversamente, os equivalentes ventilatórios, a inclinação da eficiência do consumo de oxigênio, e o pico do pulso de oxigênio foram semelhantes. A análise do subgrupo de 42 sujeitos com TECP prévio revelou uma redução significativa no pico de velocidade da esteira no subgrupo com nível leve de doença, e no consumo de oxigênio no pico e nos limiares ventilatórios nos subgrupos com níveis moderado/grave. Por outro lado, os equivalentes ventilatórios, a inclinação da eficiência do consumo de oxigênio e o pico do pulso de oxigênio não apresentaram alterações significativas. CONCLUSÕES: A fadiga do músculo periférico foi a etiologia de limitação de exercício mais comum em pacientes pós-COVID-19 independentemente da gravidade da doença. Os dados sugerem que o tratamento deve enfatizar programas de reabilitação abrangentes, incluindo componentes aeróbicos e de fortalecimento muscular.

Oxygen Consumption with High-Flow Nasal Oxygen versus Mechanical Ventilation- An International Multicenter Observational Study in COVID-19 Patients (PROXY-COVID).

The COVID-19 pandemic led to local oxygen shortages worldwide. To gain a better understanding of oxygen consumption with different respiratory supportive therapies, we conducted an international multicenter observational study to determine the precise amount of oxygen consumption with high-flow nasal oxygen (HFNO) and with mechanical ventilation. A retrospective observational study was conducted in three intensive care units (ICUs) in the Netherlands and Spain. Patients were classified as HFNO patients or ventilated patients, according to the mode of oxygen supplementation with which a patient started. The primary endpoint was actual oxygen consumption; secondary endpoints were hourly and total oxygen consumption during the first two full calendar days. Of 275 patients, 147 started with HFNO and 128 with mechanical ventilation. Actual oxygen use was 4.9-fold higher in patients who started with HFNO than in patients who started with ventilation (median 14.2 [8.4-18.4] versus 2.9 [1.8-4.1] L/minute; mean difference = 11.3 [95% CI 11.0-11.6] L/minute; P < 0.01). Hourly and total oxygen consumption were 4.8-fold (P < 0.01) and 4.8-fold (P < 0.01) higher. Actual oxygen consumption, hourly oxygen consumption, and total oxygen consumption are substantially higher in patients that start with HFNO compared with patients that start with mechanical ventilation. This information may help hospitals and ICUs predicting oxygen needs during high-demand periods and could guide decisions regarding the source of distribution of medical oxygen.

Effect of COVID-19 Lockdown on Cardiovascular Health in University Students.

BACKGROUND: A decrease in physical activity levels among university students during the COVID-19 pandemic is well-documented in the literature. However, the effect of lockdown restrictions on cardiovascular fitness has not been thoroughly investigated. METHODS: The aim of the study was to assess the possible changes in cardiovascular fitness among university students during a 14-week period of the COVID-19 pandemic. Thirteen female and seven male tourism and recreation students participated in the study. Examinations were conducted in November 2020 and in February/March 2021. Students performed the PWC170 test on a cycling ergometer. Maximal oxygen consumption was calculated based on the PWC170 test results. Blood pressure and heart rate were measured at rest, as well as in the 1st and 5th minute of post-exercise recovery. RESULTS: No substantial changes were observed in maximal oxygen consumption level when comparing autumn and winter indices. Male students presented elevated blood pressure whereas female students presented normal blood pressure. Heart-rate and blood-pressure indices did not show substantial alternations in examined students during analyzed period. CONCLUSIONS: Fourteen weeks of lockdown had little effect on the cardiovascular health of tourism and recreation students.

Cardiopulmonary Exercise Testing Distinguishes between Post-COVID-19 as a Dysfunctional Syndrome and Organ Pathologies.

(1) Background: Dyspnea is one of the most frequent symptoms among post-COVID-19 patients. Cardiopulmonary exercise testing (CPET) is key to a differential diagnosis of dyspnea. This study aimed to describe and classify patterns of cardiopulmonary dysfunction in post-COVID-19 patients, using CPET. (2) Methods: A total of 143 symptomatic post-COVID-19 patients were included in the study. All patients underwent CPET, including oxygen consumption, slope of minute ventilation to CO2 production, and capillary blood gas testing, and were evaluated for signs of limitation by two experienced examiners. In total, 120 patients reached a satisfactory level of exertion and were included in further analyses. (3) Results: Using CPET, cardiovascular diseases such as venous thromboembolism or ischemic and nonischemic heart disease were identified as either cardiac (4.2%) or pulmonary vascular (5.8%) limitations. Some patients also exhibited dysfunctional states, such as deconditioning (15.8%) or pulmonary mechanical limitation (9.2%), mostly resulting from dysfunctional breathing patterns. Most (65%) patients showed no signs of limitation. (4) Conclusions: CPET can identify patients with distinct limitation patterns, and potentially guide further therapy and rehabilitation. Dysfunctional breathing and deconditioning are crucial factors for the evaluation of post-COVID-19 patients, as they can differentiate these dysfunctional syndromes from organic diseases. This highlights the importance of dynamic (as opposed to static) investigations in the post-COVID-19 context.

Oxygen uptake kinetics and chronotropic responses to exercise are impaired in survivors of severe COVID-19.

The post-acute phase of coronavirus disease 2019 (COVID-19) is often marked by several persistent symptoms and exertional intolerance, which compromise survivors' exercise capacity. This was a cross-sectional study aiming to investigate the impact of COVID-19 on oxygen uptake (V̇o2) kinetics and cardiopulmonary function in survivors of severe COVID-19 about 3-6 mo after intensive care unit (ICU) hospitalization. Thirty-five COVID-19 survivors previously admitted to ICU (5 ± 1 mo after hospital discharge) and 18 controls matched for sex, age, comorbidities, and physical activity level with no prior history of SARS-CoV-2 infection were recruited. Subjects were submitted to a maximum-graded cardiopulmonary exercise test (CPX) with an initial 3-min period of a constant, moderate-intensity walk (i.e., below ventilatory threshold, VT). V̇o2 kinetics was remarkably impaired in COVID-19 survivors as evidenced at the on-transient by an 85% (P = 0.008) and 28% (P = 0.001) greater oxygen deficit and mean response time (MRT), respectively. Furthermore, COVID-19 survivors showed an 11% longer (P = 0.046) half-time of recovery of V̇o2 (T1/2V̇o2) at the off-transient. CPX also revealed cardiopulmonary impairments following COVID-19. Peak oxygen uptake (V̇o2peak), percent-predicted V̇o2peak, and V̇o2 at the ventilatory threshold (V̇o2VT) were reduced by 17%, 17%, and 12% in COVID-19 survivors, respectively (all P < 0.05). None of the ventilatory parameters differed between groups (all P > 0.05). In addition, COVID-19 survivors also presented with blunted chronotropic responses (i.e., chronotropic index, maximum heart rate, and heart rate recovery; all P < 0.05). These findings suggest that COVID-19 negatively affects central (chronotropic) and peripheral (metabolic) factors that impair the rate at which V̇o2 is adjusted to changes in energy demands.NEW & NOTEWORTHY Our findings provide novel data regarding the impact of COVID-19 on submaximal and maximal cardiopulmonary responses to exercise. We showed that V̇o2 kinetics is significantly impaired at both the onset (on-transient) and the recovery phase (off-transient) of exercise in these patients. Furthermore, our results suggest that survivors of severe COVID-19 may have a higher metabolic demand at a walking pace. These findings may partly explain the exertional intolerance frequently observed following COVID-19.

The Evaluation of Functional Abilities Using the Modified Fullerton Functional Fitness Test Is a Valuable Accessory in Diagnosing Men with Heart Failure.

The assessment of functional abilities reflects the ability to perform everyday life activities that require specific endurance and physical fitness. The Fullerton functional fitness test (FFFT) seems to be the most appropriate for assessing physical fitness in heart failure (HF) patients. The study group consisted of 30 consecutive patients hospitalized for the routine assessment of HF with a reduced ejection fraction (HFrEF). They formed the study group, and 24 healthy subjects formed the control group. Each patient underwent a cardiopulmonary exercise test (CPET), transthoracic echocardiography and FFFT modified by adding the measurement of the handgrip force of the dominant limb with the digital dynamometer. The HF patients had significantly lower peak oxygen uptake (peakVO2), maximal minute ventilation, and higher ventilatory equivalent (VE/VCO2). The concentrations of B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) were significantly higher in the study group. The results of all the FFFT items were significantly worse in the study group. FFFT parameters, together with the assessment of the strength of the handgrip, strongly correlated with the results of standard tests in HF. FFFT is an effective and safe tool for the functional evaluation of patients with HFrEF. Simple muscle strength measurement with a hand-held dynamometer can become a convenient and practical indicator of muscle strength in HF patients.

COVID-19 and physical activity in sedentary individuals: differences in metabolic, cardiovascular, and respiratory responses during aerobic exercise performed with and without a surgical face masks.

BACKGROUND: The Coronavirus-19 (COVID-19) impairs metabolic, cardiovascular, and pulmonary functions in human metabolism, and wearing face masks is recommended for the prevention of contracting or exposing others to cardio-respiratory infections. Since the effect of wearing a surgical face mask (SFM) on cardiopulmonary exercise capacity has not been systematically reported we aimed to determine the effects of wearing SFM during an incremental walking test on metabolic, cardiovascular, and pulmonary gas exchange responses in sedentary individuals. METHODS: The evaluations were performed using a repeated measures study design. Seven sedentary males (age: 40 years, height: 178 cm, weight: 88 kg, BMI: 28 kg/m2, VO2max: 32.7±3.9 mL/kg/min) and 7 sedentary female participants (age: 34 years, height: 169 cm, weight: 62 kg, BMI: 22 kg/m2, VO2max: 32.1±6.8 mL/kg/min) volunteered to participate in the current study. Anthropometric parameters were measured using a Bioelectrical impedance analysis prior to each testing session. The measures of lung function assessed by spirometry, breathing pattern, maximal exercise capacity with-and-without mask were measured with a breath-by-breath automated exercise metabolic system during incremental Bruce protocol on a treadmill with two consecutive sessions with 48-h intervals. Blood pressure values (systolic and diastolic pressure) of the individuals were taken and recorded within 1 minute at the end of every ten minutes, without speed changes. RESULTS: VO2, VCO2, and VE were significantly lower during exercise performed with SFM (P<0.001). Heart rate, systolic and diastolic blood pressure were also found significantly higher during exercise performed with SFM (P<0.01). CONCLUSIONS: Wearing a SFM during incremental walking predispose a decrease in oxygen delivery while increasing pulmonary ventilation in sedentary individuals. Thus, it could be speculated that surgical face masks have a negative impact on oxygen delivery during exercise which results in decreased exercise performance due to the restricted ventilatory conditions.

Longitudinal assessment of cardiorespiratory fitness and body mass of young healthy adults during COVID-19 pandemic.

Physical activity was reduced during the COVID-19 pandemic, especially when lockdowns were mandated; however, little is known about the impact of these lifestyle changes on objective measures of cardiorespiratory fitness. To address this knowledge gap, we evaluated the cardiorespiratory fitness of 14 young healthy adults (4 women, age: 27 ± 6 yr) just before the pandemic and after ∼1 yr of public health measures being in place. During fitness assessments, participants performed submaximal pseudorandom cycling exercise to assess cardiorespiratory kinetics, and a 25 W·min-1 ramp-incremental cycling test to determine peak oxygen uptake (V̇o2). Cluster analysis identified two subgroups of participants: those who had reduced peak V̇o2 at the 1-yr follow-up (-0.50 ± 0.17 L·min-1) and those whose peak V̇o2 was maintained (0.00 ± 0.10 L·min-1). Participants with reduced peak V̇o2 also exhibited slower heart rate kinetics (interaction: P = 0.01), reduced peak O2 pulse (interaction: P < 0.001), and lower peak work rate (interaction: P < 0.001) after 1 yr of the pandemic, whereas these variables were unchanged in the group of participants who maintained peak V̇o2. Regardless of changes in peak V̇o2, both subgroups of participants gained body mass (main effect: P = 0.002), which was negatively correlated with participants' level of self-reported physical activity level at the follow-up assessment (mass: ρ = -0.59, P = 0.03) These findings suggest that some young healthy individuals lost cardiorespiratory fitness during the pandemic, whereas others gained weight, but both changes could potentially increase the risk of adverse health outcomes and disease later in life if left unaddressed.NEW & NOTEWORTHY Some young healthy adults experienced cardiovascular deconditioning during the COVID-19 pandemic, with measurable reductions in cardiorespiratory fitness, whereas others experienced no change in fitness but gained body mass, which was related to self-reported physical activity during the pandemic.

Cardiopulmonary Exercise Testing in Patients with Post-COVID-19 Syndrome.

BACKGROUND AND AIM: Several reports have shown the persistence of long term symptoms after the initial COVID-19 infection (post-COVID-19 syndrome). The objective of this study was to analyze the characteristics of cardiopulmonary exercise testing (CPET) performed in patients with a history of COVID-19, comparing subjects according to the presence of post-COVID-19 syndrome. METHODS: A cross-sectional study was performed. Consecutive patients >18 years with history of SARS-CoV-2 infection confirmed by polymerase chain reaction test and a CPET performed between 45 and 120 days after the viral episode were included. The association between variables related to CPET and post-COVID-19 syndrome was assessed using univariate and multivariate analysis. RESULTS: A total of 200 patients (mean age 48.8±14.3 years, 51% men) were included. Patients with post-COVID-19 syndrome showed significantly lower main peak VO2 (25.8±8.1mL/min/kg vs. 28.8±9.6mL/min/kg, p=0.017) as compared to asymptomatic subjects. Moreover, patients with post-COVID-19 syndrome developed symptoms more frequently during CPET (52.7% vs. 13.7%, p<0.001) and were less likely to reach the anaerobic threshold (50.9% vs. 72.7%, p=0.002) when compared to asymptomatic subjects. These findings were not modified when adjusting for confounders. CONCLUSION: Our data suggest that post-COVID-19 syndrome was associated with less peak VO2, a lower probability of achieving the anaerobic threshold and a higher probability of presenting symptoms during the CPET. Future studies are needed to determine if these abnormalities during CPET would have prognostic value.

Mild-to-moderate COVID-19 impact on the cardiorespiratory fitness in young and middle-aged populations.

The goal of the present study was to compare pulmonary function test (PFT) and cardiopulmonary exercise test (CPET) performance in COVID-19 survivors with a control group (CG). This was a cross-sectional study. Patients diagnosed with COVID-19, without severe signs and symptoms, were evaluated one month after the infection. Healthy volunteers matched for sex and age constituted the control group. All volunteers underwent the following assessments: i) clinical evaluation, ii) PTF; and iii) CPET on a cycle ergometer. Metabolic variables were measured by the CareFusion Oxycon Mobile device. In addition, heart rate responses, peak systolic and diastolic blood pressure, and perceived exertion were recorded. Twenty-nine patients with COVID-19 and 18 healthy control subjects were evaluated. Surviving patients of COVID-19 had a mean age of 40 years and had higher body mass index and persistent symptoms compared to the CG (P<0.05), but patients with COVID-19 had more comorbidities, number of medications, and greater impairment of lung function (P<0.05). Regarding CPET, patients surviving COVID-19 had reduced peak workload, oxygen uptake (V̇O2), carbon dioxide output (V̇CO2), circulatory power (CP), and end-tidal pressure for carbon dioxide (PETCO2) (P<0.05). Additionally, survivors had depressed chronotropic and ventilatory responses, low peak oxygen saturation, and greater muscle fatigue (P<0.05) compared to CG. Despite not showing signs and symptoms of severe disease during infection, adult survivors had losses of lung function and cardiorespiratory capacity one month after recovery from COVID-19. In addition, cardiovascular, ventilatory, and lower limb fatigue responses were the main exercise limitations.

Aerobic capacity of professional soccer players before and after COVID-19 infection.

This investigation aimed to assess the aerobic capacity of professional soccer players pre-and post-COVID-19 infection. Twenty-one division-1 elite soccer players (age 24.24 ± 5.75 years, height 178.21 ± 5.44 cm, weight 74.12 ± 5.21 kg) participated in this study. This observational study compared the same players' aerobic capacity pre-, and 60-days post COVID-19 recovery. The statistical analysis demonstrated that the infected players had significantly lower VO2max values [t(20) = 5.17, p < 0.01, d = 0.613 (medium effect)], and significantly lower VO2 values at respiratory compensation point (RC) [t(20) = 2.97, p < 0.05, d = 0.39 (small effect)] after recovery. Furthermore, results indicated a significantly lower running time (RT) on the treadmill [t(20) = 4.84, p < 0.01, d = 0.46 (small effect)] when compared to the results that were obtained before they got infected. In addition, velocity at VO2max (VVO2max) was significantly lower [t(20) = 2.34, p < 0.05, d = 0.41 (small effect)] and the heart rate values at ventilatory threshold (VT) [t(20) = -2.79, p < 0.01, d = 0.55 (medium effect)] and RC [t(20) = -3.72, p < 0.01, d = 0.52 (medium effect)] were significantly higher post-recovery. The aforementioned findings indicate that post COVID-19 soccer players may not reach full recovery at two months. Therefore, our results highlight that further adaptations and improvements are needed with regard to aerobic capacity before soccer players return to professional games.

Estimated Oxygen Consumption with the Abbreviated Method and Its Association with Vaccination and PCR Tests for COVID-19 from Socio-Demographic, Anthropometric, Lifestyle, and Morbidity Outcomes in Chilean Adults.

COVID-19 causes cardiovascular and lung problems that can be aggravated by confinement, but the practice of physical activity (PA) could lessen these effects. The objective of this study was to evaluate the association of maximum oxygen consumption (V˙O2max) with vaccination and PCR tests in apparently healthy Chilean adults. An observational and cross-sectional study was performed, in which 557 people from south-central Chile participated, who answered an online questionnaire on the control of COVID-19, demographic data, lifestyles, and diagnosis of non-communicable diseases. V˙O2max was estimated with an abbreviated method. With respect to the unvaccinated, those who received the first (OR:0.52 [CI:0.29;0.95], p = 0.019) and second vaccine (OR:0.33 [CI:0.18;0.59], p = 0.0001) were less likely to have an increased V˙O2max. The first vaccine was inversely associated with V˙O2max (mL/kg/min) (ß:-1.68 [CI:-3.06; -0.3], p = 0.017), adjusted for BMI (ß:-1.37 [CI:-2.71; -0.03], p = 0.044) and by demographic variables (ß:-1.82 [CI:-3.18; -0.46], p = 0.009); similarly occur for the second vaccine (ß: between -2.54 and -3.44, p < 0.001) on models with and without adjustment. Having taken a PCR test was not significantly associated with V˙O2max (mL/kg/min). It is concluded that vaccination significantly decreased V˙O2max, although it did not indicate cause and effect. There is little evidence of this interaction, although the results suggest an association, since V˙ O2max could prevent and attenuate the contagion symptoms and effects.

Obese patients with long COVID-19 display abnormal hyperventilatory response and impaired gas exchange at peak exercise.

Aim: To analyze the impact of obesity on cardiopulmonary response to exercise in people with chronic post-COVID-19 syndrome. Patients & methods: Consecutive subjects with chronic post-COVID syndrome 6 months after nonsevere acute infection were included. All patients received a complete clinical evaluation, lung function tests and cardiopulmonary exercise testing. A total of 51 consecutive patients diagnosed with chronic post-COVID-19 were enrolled in this study. Results: More than half of patients with chronic post-COVID-19 had a significant alteration in aerobic exercise capacity (VO2peak) 6 months after hospital discharge. Obese long-COVID-19 patients also displayed a marked reduction of oxygen pulse (O2pulse). Conclusion: Obese patients were more prone to have pathological pulmonary limitation and pulmonary gas exchange impairment to exercise compared with nonobese COVID-19 patients.

In this study, the cardiopulmonary response to exercise in people with chronic post-COVID-19 syndrome was analyzed. More than half of patients diagnosed with chronic post-COVID-19 had reduced exercise capacity 6 months after hospital discharge. In addition, patients with chronic post-COVID-19 syndrome who were overweight or obese displayed exaggerated hyperventilation along with an impairment of oxygenation at peak exercise.

The effect of medium-term recovery status after COVID-19 illness on cardiopulmonary exercise capacity in a physically active adult population.

A failure to fully recover following coronavirus disease 2019 (COVID-19) may have a profound impact on high-functioning populations ranging from frontline emergency services to professional or amateur/recreational athletes. The aim of the study is to describe the medium-term cardiopulmonary exercise profiles of individuals with "persistent symptoms" and individuals who feel "recovered" after hospitalization or mild-moderate community infection following COVID-19 to an age, sex, and job-role matched control group. A total of 113 participants underwent cardiopulmonary functional tests at a mean of 159 ± 7 days (∼5 mo) following acute illness; 27 hospitalized with persistent symptoms (hospitalized-symptomatic), 8 hospitalized and now recovered (hospitalized-recovered); 34 community managed with persistent symptoms (community-symptomatic); 18 community managed and now recovered (community-recovered); and 26 controls. Hospitalized groups had the least favorable body composition (body mass, body mass index, and waist circumference) compared with controls. Hospitalized-symptomatic and community-symptomatic individuals had a lower oxygen uptake (V̇o2) at peak exercise (hospitalized-symptomatic, 29.9 ± 5.0 mL/kg/min; community-symptomatic, 34.4 ± 7.2 mL/kg/min; vs. control 43.9 ± 3.1 mL/kg/min, both P < 0.001). Hospitalized-symptomatic individuals had a steeper V̇e/V̇co2 slope (lower ventilatory efficiency) (30.5 ± 5.3 vs. 25.5 ± 2.6, P = 0.003) versus. controls. Hospitalized-recovered had a significantly lower oxygen uptake at peak (32.6 ± 6.6 mL/kg/min vs. 43.9 ± 13.1 mL/kg/min, P = 0.015) compared with controls. No significant differences were reported between community-recovered individuals and controls in any cardiopulmonary parameter. In conclusion, medium-term findings suggest that community-recovered individuals did not differ in cardiopulmonary fitness from physically active healthy controls. This suggests their readiness to return to higher levels of physical activity. However, the hospitalized-recovered group and both groups with persistent symptoms had enduring functional limitations, warranting further monitoring, rehabilitation, and recovery.NEW & NOTEWORTHY At 5 mo postinfection, community-treated individuals who feel recovered have comparable cardiopulmonary exercise profiles to the physically trained and active controls, suggesting a readiness to return to higher intensity/volumes of exercise. However, both symptomatic groups and the hospital-recovered group have persistent functional limitations when compared with active controls, supporting the requirement for ongoing monitoring, rehabilitation, and recovery.

Aging, VO2 max, entropy, and COVID-19.

The decline in human performance with age at 5000 m, an athletic event requiring high VO2 max, is remarkably precise, and unavoidable, and related to entropy, even at an individual level. Women and men show an identical age-related decline, up to ~100 years old. The precision of the decline shows the limitations for therapy of aging. Mortality incidence for COVID-19 shows a similar relationship. We propose that initial VO2 max has a critical role in COVID sensitivity because of the direct relationship of disease severity with oxygen use, and the parallel decline in aging.