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1.
Cochrane Database Syst Rev ; 10: CD013400, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33112424

RESUMO

BACKGROUND: Congenital heart disease (ConHD) affects approximately 1% of all live births. People with ConHD are living longer due to improved medical intervention and are at risk of developing non-communicable diseases. Cardiorespiratory fitness (CRF) is reduced in people with ConHD, who deteriorate faster compared to healthy people. CRF is known to be prognostic of future mortality and morbidity: it is therefore important to assess the evidence base on physical activity interventions in this population to inform decision making. OBJECTIVES: To assess the effectiveness and safety of all types of physical activity interventions versus standard care in individuals with congenital heart disease. SEARCH METHODS: We undertook a systematic search on 23 September 2019 of the following databases: CENTRAL, MEDLINE, Embase, CINAHL, AMED, BIOSIS Citation Index, Web of Science Core Collection, LILACS and DARE. We also searched ClinicalTrials.gov and we reviewed the reference lists of relevant systematic reviews. SELECTION CRITERIA: We included randomised controlled trials (RCT) that compared any type of physical activity intervention against a 'no physical activity' (usual care) control. We included all individuals with a diagnosis of congenital heart disease, regardless of age or previous medical interventions.  DATA COLLECTION AND ANALYSIS: Two review authors (CAW and CW) independently screened all the identified references for inclusion. We retrieved and read all full papers; and we contacted study authors if we needed any further information. The same two independent reviewers who extracted the data then processed the included papers, assessed their risk of bias using RoB 2 and assessed the certainty of the evidence using the GRADE approach. The primary outcomes were: maximal cardiorespiratory fitness (CRF) assessed by peak oxygen consumption; health-related quality of life (HRQoL) determined by a validated questionnaire; and device-worn 'objective' measures of physical activity. MAIN RESULTS: We included 15 RCTs with 924 participants in the review. The median intervention length/follow-up length was 12 weeks (12 to 26 interquartile range (IQR)). There were five RCTs of children and adolescents (n = 500) and 10 adult RCTs (n = 424). We identified three types of intervention: physical activity promotion; exercise training; and inspiratory muscle training. We assessed the risk of bias of results for CRF as either being of some concern (n = 12) or at a high risk of bias (n = 2), due to a failure to blind intervention staff. One study did not report this outcome. Using the GRADE method, we assessed the certainty of evidence as moderate to very low across measured outcomes. When we pooled all types of interventions (physical activity promotion, exercise training and inspiratory muscle training), compared to a 'no exercise' control CRF may slightly increase, with a mean difference (MD) of 1.89 mL/kg-1/min-1 (95% CI -0.22 to 3.99; n = 732; moderate-certainty evidence). The evidence is very uncertain about the effect of physical activity and exercise interventions on HRQoL. There was a standardised mean difference (SMD) of 0.76 (95% CI -0.13 to 1.65; n = 163; very low certainty evidence) in HRQoL. However, we could pool only three studies in a meta-analysis, due to different ways of reporting. Only one study out of eight showed a positive effect on HRQoL. There may be a small improvement in mean daily physical activity (PA) (SMD 0.38, 95% CI -0.15 to 0.92; n = 328; low-certainty evidence), which equates to approximately an additional 10 minutes of physical activity daily (95% CI -2.50 to 22.20). Physical activity and exercise interventions likely result in an increase in submaximal cardiorespiratory fitness (MD 2.05, 95% CI 0.05 to 4.05; n = 179; moderate-certainty evidence). Physical activity and exercise interventions likely increase muscular strength (MD 17.13, 95% CI 3.45 to 30.81; n = 18; moderate-certainty evidence). Eleven studies (n = 501) reported on the outcome of adverse events (73% of total studies). Of the 11 studies, six studies reported zero adverse events. Five studies reported a total of 11 adverse events; 36% of adverse events were cardiac related (n = 4); there were, however, no serious adverse events related to the interventions or reported fatalities (moderate-certainty evidence). No studies reported hospital admissions. AUTHORS' CONCLUSIONS: This review summarises the latest evidence on CRF, HRQoL and PA. Although there were only small improvements in CRF and PA, and small to no improvements in HRQoL, there were no reported serious adverse events related to the interventions. Although these data are promising, there is currently insufficient evidence to definitively determine the impact of physical activity interventions in ConHD. Further high-quality randomised controlled trials are therefore needed, utilising a longer duration of follow-up.


Assuntos
Exercícios Respiratórios , Aptidão Cardiorrespiratória/fisiologia , Exercício Físico/fisiologia , Cardiopatias Congênitas/reabilitação , Adolescente , Adulto , Viés , Criança , Feminino , Humanos , Masculino , Força Muscular , Consumo de Oxigênio/fisiologia , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
J Vis Exp ; (162)2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32894267

RESUMO

Near infrared spectroscopy (NIRS) calculates regional tissue oxygenation (rSO2) using the different absorption spectra of oxygenated and deoxygenated hemoglobin molecules. A probe placed on the skin emits light that is absorbed, scattered, and reflected by the underlying tissue. Detectors in the probe sense the amount of reflected light: this reflects the organ-specific ratio of oxygen supply and consumption - independent of pulsatile flow. Modern devices enable the simultaneous monitoring at different body sites. A rise or dip in the rSO2 curve visualizes changes in oxygen supply or demand before vital signs indicate them. The evolution of rSO2 values in relation to the starting point is more important for interpretation than are absolute values. A routine clinical application of NIRS is the surveillance of somatic and cerebral oxygenation during and after cardiac surgery. It is also administered in preterm infants at risk for necrotizing enterocolitis, newborns with hypoxic ischemic encephalopathy and a potential risk of impaired tissue oxygenation. In the future, NIRS could be increasingly used in multimodal neuromonitoring, or applied to monitor patients with other conditions (e.g., after resuscitation or traumatic brain injury).


Assuntos
Estado Terminal , Oximetria/métodos , Espectroscopia de Luz Próxima ao Infravermelho , Criança , Humanos , Lactente , Recém-Nascido , Masculino , Oximetria/instrumentação , Consumo de Oxigênio/fisiologia , Oxiemoglobinas/análise
3.
PLoS One ; 15(9): e0239463, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32960920

RESUMO

This study aimed to investigate the effects of different playing strategies on external and internal loads in female tennis players during match play. Also, the underlying effects on the technical-tactical actions and activity profiles were examined. Twelve well-trained female players (age: 25±5 years; maximum oxygen uptake: 40.9±4.3 ml/kg/min) played points against an opponent of similar ability outdoors on red-clay courts. The players played points over five playing conditions. Before each condition, the players were instructed to apply either a passive, an active, or their own playing strategy (free play) to succeed. The five conditions were played in a randomized order, whereas the condition with the own strategy was always played first and served as control. During play, the external and internal loads were investigated by 10 Hz global positioning system, 100 Hz inertial measurement unit, short-range telemetry, capillary blood, and visual analog scale procedures. A 25 Hz video camera was used to examine the technical-tactical actions and activity profiles. Compared to the control condition, the passive, active, and mixed playing strategy conditions induce up to large effects on the external loads (running distances with high acceleration and deceleration), up to moderate effects on the internal loads (energy expenditures spent with high metabolic power, lactate concentration, and rating of effort), and up to very large effects on the technical-tactical actions (number of ground strokes and errors) and activity profiles (strokes per rally, rally duration, work to rest ratio, and effective playing time). Our study shows that passive, active, and mixed playing strategies have an impact on the external and internal loads, technical-tactical actions, and activity profiles of female tennis players during match play. This finding should be considered for practical purposes like match analyses and training procedures in the tennis environment.


Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Tênis/fisiologia , Aceleração , Adulto , Feminino , Sistemas de Informação Geográfica , Humanos , Ácido Láctico/metabolismo , Oxigênio/metabolismo , Consumo de Oxigênio/fisiologia , Adulto Jovem
4.
J Sports Med Phys Fitness ; 60(8): 1110-1117, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32955837

RESUMO

BACKGROUND: Vinyasa yoga has been recently promoted as one of the most popular mindful exercises to improve overall health, including body weight management. The purpose of this study was to determine the metabolic response of 24 moderately trained individuals during a 90-min group Vinyasa yoga routine. METHODS: Heart rate (HR) time course of 12 males and 12 females (age: 39±7.33 years) was recorded during two group Vinyasa yoga sessions consisted of four sections (warm-up, high-intensity Surya Namaskar (HSN), no Surya Namaskar postures, and cool-down). Maximal oxygen uptake (V̇O2peak) and maximum HR had been estimated earlier after a maximal treadmill test. V̇O2 during Vinyasa yoga sessions was estimated from individual regression equations using the relationship of V̇O2 and HR values derived from V̇O2peak test, while the metabolic rate (kcal/min) was calculated from the relationship of HR and kcal/min. Total session energy consumption was the average value of the two yoga sessions. RESULTS: The 2 (gender) × 4 (sections) mixed ANOVA revealed no significant interaction between the two factors (P=0.101) for the mean metabolic rate (7.1±2.6 kcal/min). Mean metabolic rate thought was higher (P=0.015) in males compared to females at each section. Also, significant differences were found among the four Vinyasa yoga sections (P<0.001) in the rate of energy expenditure, with HSN presenting the highest mean values (P<0.05). CONCLUSIONS: It seems that systematic participation in Vinyasa yoga may effectively improve cardiorespiratory fitness and promote body weight loss, as an alternative method to traditional aerobic exercise.


Assuntos
Aptidão Cardiorrespiratória , Metabolismo Energético , Perda de Peso , Ioga , Adulto , Exercício de Arrefecimento/fisiologia , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Postura/fisiologia , Fatores Sexuais , Exercício de Aquecimento/fisiologia
5.
Lancet ; 396(10253): 759-769, 2020 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-32871100

RESUMO

BACKGROUND: Cardiac muscle hypercontractility is a key pathophysiological abnormality in hypertrophic cardiomyopathy, and a major determinant of dynamic left ventricular outflow tract (LVOT) obstruction. Available pharmacological options for hypertrophic cardiomyopathy are inadequate or poorly tolerated and are not disease-specific. We aimed to assess the efficacy and safety of mavacamten, a first-in-class cardiac myosin inhibitor, in symptomatic obstructive hypertrophic cardiomyopathy. METHODS: In this phase 3, randomised, double-blind, placebo-controlled trial (EXPLORER-HCM) in 68 clinical cardiovascular centres in 13 countries, patients with hypertrophic cardiomyopathy with an LVOT gradient of 50 mm Hg or greater and New York Heart Association (NYHA) class II-III symptoms were assigned (1:1) to receive mavacamten (starting at 5 mg) or placebo for 30 weeks. Visits for assessment of patient status occurred every 2-4 weeks. Serial evaluations included echocardiogram, electrocardiogram, and blood collection for laboratory tests and mavacamten plasma concentration. The primary endpoint was a 1·5 mL/kg per min or greater increase in peak oxygen consumption (pVO2) and at least one NYHA class reduction or a 3·0 mL/kg per min or greater pVO2 increase without NYHA class worsening. Secondary endpoints assessed changes in post-exercise LVOT gradient, pVO2, NYHA class, Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score (KCCQ-CSS), and Hypertrophic Cardiomyopathy Symptom Questionnaire Shortness-of-Breath subscore (HCMSQ-SoB). This study is registered with ClinicalTrials.gov, NCT03470545. FINDINGS: Between May 30, 2018, and July 12, 2019, 429 adults were assessed for eligibility, of whom 251 (59%) were enrolled and randomly assigned to mavacamten (n=123 [49%]) or placebo (n=128 [51%]). 45 (37%) of 123 patients on mavacamten versus 22 (17%) of 128 on placebo met the primary endpoint (difference +19·4%, 95% CI 8·7 to 30·1; p=0·0005). Patients on mavacamten had greater reductions than those on placebo in post-exercise LVOT gradient (-36 mm Hg, 95% CI -43·2 to -28·1; p<0·0001), greater increase in pVO2 (+1·4 mL/kg per min, 0·6 to 2·1; p=0·0006), and improved symptom scores (KCCQ-CSS +9·1, 5·5 to 12·7; HCMSQ-SoB -1·8, -2·4 to -1·2; p<0·0001). 34% more patients in the mavacamten group improved by at least one NYHA class (80 of 123 patients in the mavacamten group vs 40 of 128 patients in the placebo group; 95% CI 22·2 to 45·4; p<0·0001). Safety and tolerability were similar to placebo. Treatment-emergent adverse events were generally mild. One patient died by sudden death in the placebo group. INTERPRETATION: Treatment with mavacamten improved exercise capacity, LVOT obstruction, NYHA functional class, and health status in patients with obstructive hypertrophic cardiomyopathy. The results of this pivotal trial highlight the benefits of disease-specific treatment for this condition. FUNDING: MyoKardia.


Assuntos
Benzilaminas/uso terapêutico , Miosinas Cardíacas/antagonistas & inibidores , Cardiomiopatia Hipertrófica/tratamento farmacológico , Uracila/análogos & derivados , Antagonistas Adrenérgicos beta/uso terapêutico , Idoso , Benzilaminas/efeitos adversos , Bloqueadores dos Canais de Cálcio/uso terapêutico , Cardiomiopatia Hipertrófica/fisiopatologia , Fármacos Cardiovasculares/uso terapêutico , Método Duplo-Cego , Tolerância ao Exercício/fisiologia , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Avaliação de Resultados da Assistência ao Paciente , Uracila/efeitos adversos , Uracila/uso terapêutico
6.
Sports Biomech ; 19(6): 723-737, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32942954

RESUMO

The aim of this study was to understand if and how surface-induced vibrations and road bike damping affect short-term neuromuscular performance in cycling. Thirty cyclists (mass 75.9 ± 8.9 kg, height 1.82 ± 0.05 m, Vo2max 63.0 ± 6.8 ml/min/kg) performed steady-state and maximum effort tests with and without vibration exposure (front dropout: 44 Hz, 4.1 mm; rear dropout: 38 Hz, 3.5 mm) on a damped and a nondamped bike. Transmitted accelerations to the musculoskeletal system, activation of lower extremity muscles (gast. med., soleus, vast. med., rec. fem.) and upper body muscles (erec. spinae, deltoideus, tric. brachii), oxygen uptake, heart rate and crank power output were measured. The main findings indicate a transmission of vibration to the whole body, but since no major propulsive muscles increase their activation with vibration, the systemic energy demand increases only marginally with vibration. Damping reduces vibrations at the upper body, which indicates an increase in comfort, but has no effect on the vibration transfer to the lower extremities. Therefore, road bike damping does not affect neuromuscular response of the propulsive muscle groups and energy demand. Consequently, short-term power output does not increase with damping.


Assuntos
Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Meio Ambiente , Músculo Esquelético/fisiologia , Vibração , Aceleração , Fenômenos Biomecânicos , Estudos Transversais , Frequência Cardíaca/fisiologia , Humanos , Extremidade Inferior/fisiologia , Masculino , Músculo Esquelético/inervação , Consumo de Oxigênio/fisiologia , Tronco/fisiologia , Extremidade Superior/fisiologia
7.
PLoS One ; 15(8): e0237010, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32780739

RESUMO

This study analyzed the physiological adjustments caused by the use of the Elevation training mask® (2.0), an airflow restriction mask (ARM) during continuous exercise. Eighteen physically active participants (12 men and 6 women) were randomized to two protocols: continuous exercise with mask (CE-ARM) and continuous exercise without mask (CE). Exercise consisted of cycling for 20 minutes at 60% of maximum power. Metabolic variables, lactate, and gas concentration were obtained from arterialized blood samples at pre and post exercise. Continuous expired gases and myoelectric activity of the quadriceps were performed at rest and during the test. We observed no reduction in oxygen saturation in CE-ARM, leading to lower pH, higher carbon dioxide, and greater hematocrit (all p <0.05). The expired gas analysis shows that the CE-ARM condition presented higher oxygen uptake and expired carbon dioxide concentrations (p <0.05). The CE-ARM condition also presented lower ventilatory volume, ventilatory frequency, and expired oxygen pressure (p <0.05). No changes in electromyography activity and lactate concentrations were identified. We conclude that using ARM does not induce hypoxia and represents an additional challenge for the control of acid-base balance, and we suggest the use of ARM as being suitable for respiratory muscle training.


Assuntos
Exercício Físico/fisiologia , Consumo de Oxigênio/fisiologia , Ventilação Pulmonar/fisiologia , Adulto , Exercícios Respiratórios/métodos , Dióxido de Carbono/sangue , Teste de Esforço/métodos , Feminino , Voluntários Saudáveis , Humanos , Hipóxia/metabolismo , Pulmão/metabolismo , Masculino , Máscaras , Oxigênio/sangue , Respiração , Testes de Função Respiratória
8.
Pediatrics ; 146(3)2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32848028

RESUMO

BACKGROUND AND OBJECTIVES: Preterm infants with necrotizing enterocolitis (NEC) are known to have worse neurodevelopmental outcomes, but there is no substantial evidence to support an underlying pathophysiology. We aimed to examine whether cerebral oxygenation differs in those infants who develop NEC compared to cerebral oxygenation in those who do not. METHODS: We examined 48 infants <30 weeks' gestation admitted to a tertiary level NICU from October 2016 to May 2018. Infants with birth weight less than or equal to the second percentile, abnormal antenatal dopplers or twin-to-twin-transfusion-syndrome were excluded. Cerebral oximetry measurements were performed by using a near-infrared spectroscopy (NIRS) monitor weekly for 60 minutes, allowing measurement of cerebral tissue oxygenation index from the first week of life to 36 weeks postconceptional age. Weekly clinical status was also recorded. NEC was defined as greater than or equal to Bell stage 2. RESULTS: The median birth weight was 884 g (range of 460-1600 g), the median weeks' gestational age was 26 + 3/7 (23 + 0/7 to 29 + 6/7), and 52% were girls. In total, 276 NIRS measurements were completed, and 7 infants developed NEC. NIRS measurements from 1 infant with NEC and 4 infants without NEC who developed hemorrhagic parenchymal infarcts were excluded from analysis. Infants who developed NEC had significantly lower cerebral tissue oxygenation index than those who did not (P = .011), even when adjusted for confounders, including gestational age, birth weight, patent ductus arteriosus, enteral feeds, sex, ethnicity, and hemoglobin. CONCLUSIONS: Infants with NEC have significantly lower cerebral tissue oxygenation throughout their neonatal intensive care stay in comparison with those who did not develop NEC. This is a novel finding and could explain their worse neurodevelopmental outcome.


Assuntos
Encéfalo/metabolismo , Enterocolite Necrosante/metabolismo , Consumo de Oxigênio/fisiologia , Antibioticoprofilaxia , Permeabilidade do Canal Arterial/diagnóstico por imagem , Enterocolite Necrosante/etiologia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Oximetria/instrumentação , Oximetria/métodos , Estudos Prospectivos , Espectroscopia de Luz Próxima ao Infravermelho , Fatores de Tempo
9.
Am J Physiol Regul Integr Comp Physiol ; 319(3): R323-R328, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783690

RESUMO

Black men have attenuated increases in forearm vascular conductance (FVC) and forearm blood flow (FBF) during moderate- and high-intensity rhythmic handgrip exercise compared with White men, but the underlying mechanisms are unclear. Here, we tested for the first time the hypothesis that functional sympatholysis (i.e., attenuation of sympathetic vasoconstriction in the exercising muscles) is impaired in Black men compared with White men. Thirteen White and 14 Black healthy young men were studied. FBF (duplex Doppler ultrasound) and mean arterial pressure (MAP; Finometer) were measured at rest and during rhythmic handgrip exercise at 30% maximal voluntary contraction. FVC was calculated as FBF/MAP. Sympathetic activation was induced via lower body negative pressure (LBNP) at -20 Torr for 2 min at rest and from the 3rd to the 5th min of handgrip. Sympathetic vasoconstriction was assessed as percent reductions in FVC during LBNP. The groups presented similar resting FVC, FBF, and MAP. During LBNP at rest, reductions in FVC were not different between White (-35 ± 10%) and Black men (-32 ± 14%, P = 0.616), indicating similar reflex-induced sympathetic vasoconstriction. During handgrip exercise, there were minimal reductions in FVC with LBNP in either group (White: -1 ± 7%; Black: +1 ± 8%; P = 0.523), indicating functional sympatholysis in both groups. Thus, contrary to our hypothesis, our findings indicate a preserved functional sympatholysis in healthy young Black men compared with White men, suggesting that this mechanism does not appear to contribute to reduced exercise hyperemia during moderate-intensity rhythmic handgrip in this population.


Assuntos
Exercício Físico/fisiologia , Força da Mão/fisiologia , Consumo de Oxigênio/fisiologia , Vasoconstrição/fisiologia , Adulto , Humanos , Masculino , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Sistema Nervoso Simpático/fisiopatologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-32635507

RESUMO

Indoor cycling's popularity is related to the combination of music and exercise leading to higher levels of exercise intensity. It was our objective to determine the efficacy of heart rate and rating of perceived exertion in controlling the intensity of indoor cycling classes and to quantify their association with oxygen uptake. Twelve experienced males performed three indoor cycling sessions of 45 min that differed in the way the intensity was controlled: (i) oxygen uptake; (ii) heart rate; and (iii) rating of perceived exertion using the OMNI-Cycling. The oxygen uptake levels were significantly higher (p = 0.007; µp2 = 0.254) in oxygen uptake than heart rate sessions. Oxygen uptake related to body mass was significantly higher (p < 0.005) in the oxygen uptake sessions compared with other sessions. Strong correlations were observed between oxygen uptake mean in the oxygen uptake and rating of perceived exertion sessions (r =0.986, p < 0.0001) and between oxygen uptake mean in the oxygen uptake and heart rate sessions (r = 0.977, p < 0.0001). Both heart rate and rating of perceived exertion are effective in controlling the intensity of indoor cycling classes in experienced subjects. However, the use of rating of perceived exertion is easier to use and does not require special instrumentation.


Assuntos
Ciclismo/fisiologia , Frequência Cardíaca/fisiologia , Consumo de Oxigênio/fisiologia , Esforço Físico/fisiologia , Adulto , Exercício Físico , Teste de Esforço , Feminino , Humanos , Masculino
11.
Artigo em Inglês | MEDLINE | ID: mdl-32635515

RESUMO

The aim of the present study was to analyze the effect of block (BP) and a reverse training periodization (RP) in the hematological and running performance of amateur trained athletes. Modifications in hematological, aerobic, and anaerobic running performance and countermovement jump before and after twelve weeks of BP vs. RP training programs were analyzed in 16 trained athletes (eight males: 40.0 ± 6.2 years; 179.2 ± 12.8 cm; 73.8 ± 12.2 kg; and eight females: 34.2 ± 4.1 years; 163.4 ± 9.6 cm; 57.0 ± 11.0 kg). A significant decrease in heart rate (HR) at ventilatory threshold (VT1) (p = 0.031; ES = 1.40) was observed in RP without changes in BP. In addition, RP increased significantly VO2max (p = 0.004; ES = 0.47), speed at VO2max (p = 0.001; ES = 1.07), HR at VT2 (p < 0.001; ES = 1.32) and VT1 (p = 0.046; ES = 0.57), while BP improved VO2max (p = 0.004; ES = 0.51), speed at VO2max (p = 0.016; ES = 0.92), and HR at VT2 (p = 0.023; ES = 0.78). In addition, only RP increased anaerobic performance in a running-based anaerobic sprint test (RAST) (mean sprint: p = 0.009; ES = 0.40, best sprint: p = 0.019; ES = 0.30 and total time: p = 0.009; ES = 0.40). Moreover, both types of training periodization proposed in this study maintained hematological values and efficiently improved jump performance (p = 0.044; ES = 0.6) in RP and p = 0.001; ES = 0.75 in BP). Therefore, twelve weeks of either RP or BP is an effective strategy to increase jump and aerobic running performance maintaining hematological values, but only RP increases anaerobic running performance.


Assuntos
Atletas , Desempenho Atlético/fisiologia , Frequência Cardíaca/fisiologia , Corrida/fisiologia , Feminino , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Triglicerídeos/sangue
12.
Medicine (Baltimore) ; 99(28): e21058, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32664120

RESUMO

A method to perform exercise testing for patients with hemiplegia is unavailable though over half of them have cardio-pulmonary disorders. We aimed to assess the reliability and validity of using a stepper in cardiopulmonary exercise testing (CPET) in this population.14 stroke patients with hemiplegia who failed to ride the stationary bike were included. Exclusion criteria included manual muscle strength ≦1 in the lower extremity, and conventional contraindications of CPET. They underwent CPET twice by using a stepper to evaluate test-retest reliability and validity. Additionally, 10 healthy participants underwent CPET twice on the cycle ergometer and stepper respectively.In the test-retest, the ratio of two-time difference to mean was 5.0, 3, 11.3 and 12.0% on average for peak oxygen consumption, peak heart rate (HR), anaerobic threshold and minute ventilation - carbonic dioxide production slope respectively. Cronbach's alpha coefficient of peak oxygen consumption and anaerobic threshold were 0.992 and 0.919. In the stepper exercise testing of the hemiplegic participants, the ratio of peak HR to age-predicted maximal HR was 75% on average. Peak respiratory exchange ratio (mean ±â€Šstandard deviation = 1.17 ±â€Š0.08) was not different from that of healthy controls (1.21 ±â€Š0.09). Notably, VO2 trajectory in relation to work rate is nonlinear and different in the rest-retest.This is the first research to study CPET variables in detail using stepper in patients with hemiplegia. CPET variables associated with peak are valid and reliable; nonetheless, those with sub-maximum are not. The study provides a method to do exercise testing for the patients with hemiplegia and its notice in application.


Assuntos
Teste de Esforço/métodos , Hemiplegia/reabilitação , Reabilitação do Acidente Vascular Cerebral/métodos , Idoso , Limiar Anaeróbio/fisiologia , Tolerância ao Exercício/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Reprodutibilidade dos Testes , Testes de Função Respiratória
13.
Respir Res ; 21(1): 194, 2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32698822

RESUMO

RATIONALE: Oxygen saturation to fraction of inspired oxygen ratio (SpO2/FiO2) has been described as potential predictor of poor outcome for COVID-19, without considering its time-varying behavior though. METHODS: Prognostic value of SpO2/FiO2 was evaluated by jointly modeling the longitudinal responses of SpO2/FiO2 and time-to-event data retrieved from 280 severe and critically ill (intensive care) patients with COVID-19. RESULTS: A sharply decrease of SpO2/FiO2 from the first to second measurement for non-survivors was observed, and a strong association between square root SpO2/FiO2 and mortality risk was demonstrated, with a unit decrease in the marker corresponding to 1.82-fold increase in mortality risk (95% CI: 1.56-2.13). CONCLUSIONS: The current study suggested that SpO2/FiO2 could serve as a non-invasive prognostic marker to facilitate early adjustment for treatment, thus improving overall survival.


Assuntos
Infecções por Coronavirus/sangue , Infecções por Coronavirus/mortalidade , Cuidados Críticos/métodos , Estado Terminal/mortalidade , Mortalidade Hospitalar/tendências , Consumo de Oxigênio/fisiologia , Pneumonia Viral/sangue , Pneumonia Viral/mortalidade , Biomarcadores/sangue , China , Estudos de Coortes , Infecções por Coronavirus/diagnóstico , Estado Terminal/terapia , Feminino , Humanos , Unidades de Terapia Intensiva , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Oximetria/métodos , Oxigênio/sangue , Pandemias , Pneumonia Viral/diagnóstico , Valor Preditivo dos Testes , Prognóstico
14.
Anesthesiology ; 133(2): 318-331, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32667155

RESUMO

BACKGROUND: Suboptimal tissue perfusion and oxygenation during surgery may be responsible for postoperative nausea and vomiting in some patients. This trial tested the hypothesis that muscular tissue oxygen saturation-guided intraoperative care reduces postoperative nausea and vomiting. METHODS: This multicenter, pragmatic, patient- and assessor-blinded randomized controlled (1:1 ratio) trial was conducted from September 2018 to June 2019 at six teaching hospitals in four different cities in China. Nonsmoking women, 18 to 65 yr old, and having elective laparoscopic surgery involving hysterectomy (n = 800) were randomly assigned to receive either intraoperative muscular tissue oxygen saturation-guided care or usual care. The goal was to maintain muscular tissue oxygen saturation, measured at flank and on forearm, greater than baseline or 70%, whichever was higher. The primary outcome was 24-h postoperative nausea and vomiting. Secondary outcomes included nausea severity, quality of recovery, and 30-day morbidity and mortality. RESULTS: Of the 800 randomized patients (median age, 50 yr [range, 27 to 65]), 799 were assessed for the primary outcome. The below-goal muscular tissue oxygen saturation area under the curve was significantly smaller in patients receiving muscular tissue oxygen saturation-guided care (n = 400) than in those receiving usual care (n = 399; flank, 50 vs. 140% · min, P < 0.001; forearm, 53 vs. 245% · min, P < 0.001). The incidences of 24-h postoperative nausea and vomiting were 32% (127 of 400) in the muscular tissue oxygen saturation-guided care group and 36% (142 of 399) in the usual care group, which were not significantly different (risk ratio, 0.89; 95% CI, 0.73 to 1.08; P = 0.251). There were no significant between-group differences for secondary outcomes. No harm was observed throughout the study. CONCLUSIONS: In a relatively young and healthy female patient population, personalized, goal-directed, muscular tissue oxygen saturation-guided intraoperative care is effective in treating decreased muscular tissue oxygen saturation but does not reduce the incidence of 24-h posthysterectomy nausea and vomiting.


Assuntos
Histerectomia/efeitos adversos , Cuidados Intraoperatórios/métodos , Músculo Esquelético/metabolismo , Consumo de Oxigênio/fisiologia , Náusea e Vômito Pós-Operatórios/metabolismo , Náusea e Vômito Pós-Operatórios/prevenção & controle , Adulto , Método Duplo-Cego , Feminino , Humanos , Histerectomia/tendências , Cuidados Intraoperatórios/tendências , Pessoa de Meia-Idade , Náusea e Vômito Pós-Operatórios/diagnóstico
15.
Phys Ther ; 100(10): 1852-1861, 2020 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-32671398

RESUMO

OBJECTIVE: Despite the common occurrence of lower levels of physical activity and physical fitness in youth with spina bifida (SB) who use a wheelchair, there are very few tests available to measure and assess these levels. The purpose of this study was to determine reliability and the physiologic response of the 6-minute push test (6MPT) in youth with SB who self-propel a wheelchair. METHODS: In this reliability and observational study, a sample of 53 youth with SB (5-19 years old; mean age = 13 years 7 months; 32 boys and 21 girls) who used a wheelchair performed 2 exercise tests: the 6MPT and shuttle ride test. Heart rate, minute ventilation, respiratory exchange ratio, and oxygen consumption were measured using a calibrated mobile gas analysis system and a heart rate monitor. For reliability, intraclass correlation coefficients (ICCs), SE of measurement, smallest detectable change for total covered distance, minute work, and heart rate were calculated. Physiologic response during the 6MPT was expressed as percentage of maximal values achieved during the shuttle ride test. RESULTS: The ICCs for total distance and minute work were excellent (0.95 and 0.97, respectively), and the ICC for heart rate was good (0.81). The physiologic response during the 6MPT was 85% to 89% of maximal values, except for minute ventilation (70.6%). CONCLUSIONS: For most youth with SB who use a wheelchair for mobility or sports participation, the 6MPT is a reliable, functional performance test on a vigorous level of exercise. IMPACT: This is the first study to investigate physiologic response during the 6MPT in youth (with SB) who are wheelchair using. Clinicians can use the 6MPT to evaluate functional performance and help design effective exercise programs for youth with SB who are wheelchair using.


Assuntos
Teste de Esforço/métodos , Disrafismo Espinal/reabilitação , Cadeiras de Rodas , Adolescente , Criança , Feminino , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Aptidão Física/fisiologia , Reprodutibilidade dos Testes , Disrafismo Espinal/fisiopatologia
16.
PLoS One ; 15(7): e0236507, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730281

RESUMO

In air-breathing fish a reduction of gill surface area reduces the danger of losing oxygen taken up in the air-breathing organ (ABO) to hypoxic water, but it also reduces the surface area available for ion exchange, so that ion regulation may at least in part be transferred to other organs, like the kidney or the gut. In the air-breathing Arapaima gigas, gill lamellae regress as development proceeds, and starting as a water-breathing embryo Arapaima turns into an obligate air-breathing fish with proceeding development, suggesting that ion regulation is shifted away from the gills as the fish grows. In Arapaima the kidney projects medially into the ABO and thus, probably a unique situation among fishes, is in close contact to the gas of the ABO. We therefore hypothesized that the kidney would be predestined to adopt an increased importance for ion homeostasis, because the elevated ATP turnover connected to ion transport can easily be met by aerobic metabolism based on the excellent oxygen supply directly from the ABO. We also hypothesized that in gill tissue the reduced ion regulatory activity should result in a reduced metabolic activity. High metabolic activity and exposure to high oxygen tensions are connected to the production of reactive oxygen species (ROS), therefore the tissues exposed to these conditions should have a high ROS defense capacity. Using in vitro studies, we assessed metabolic activity and ROS production of gill, kidney and ABO tissue, and determined the activity of ROS degrading enzymes in small (~ 5g, 2-3 weeks old) and larger (~ 670 g, 3-4 months old) A. gigas. Comparing the three tissues revealed that kidney tissue oxygen uptake by far exceeded the uptake measured in gill tissue or ABO. ROS production was particularly high in gill tissue, and all three tissues had a high capacity to degrade ROS. Gill tissue was characterized by high activities of enzymes involved in the glutathione pathway to degrade ROS. By contrast, the tissues of the ABO and in particular the kidney were characterized by high catalase activities, revealing different, tissue-specific strategies in ROS defense in this species. Overall the differences in the activity of cells taken from small and larger fish were not as pronounced as expected, while at the tissue level the metabolic activity of kidney cells by far exceeded the activity of ABO and gill cells.


Assuntos
Peixes/fisiologia , Consumo de Oxigênio/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Brasil , Catalase/metabolismo , Brânquias/enzimologia , Brânquias/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Rim/metabolismo , Mitocôndrias/metabolismo , Superóxido Dismutase/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-32645890

RESUMO

Background: Due to the importance of energy efficiency and economy in endurance performance, it is important to know the influence of different paddling cadences on these variables in the stand-up paddleboarding (SUP). The purpose of this study was to determine the effect of paddling at different cadences on the energy efficiency, economy, and physiological variables of international SUP race competitors. Methods: Ten male paddlers (age 28.8 ± 11.0 years; height 175.4 ± 5.1 m; body mass 74.2 ± 9.4 kg) participating in international tests carried out two test sessions. In the first one, an incremental exercise test was conducted to assess maximal oxygen uptake and peak power output (PPO). On the second day, they underwent 3 trials of 8 min each at 75% of PPO reached in the first test session. Three cadences were carried out in different trials randomly assigned between 45-55 and 65 strokes-min-1 (spm). Heart rate (HR), blood lactate, perceived sense of exertion (RPE), gross efficiency, economy, and oxygen uptake (VO2) were measured in the middle (4-min) and the end (8-min) of each trial. Results: Economy (45.3 ± 5.7 KJ·l-1 at 45 spm vs. 38.1 ± 5.3 KJ·l-1 at 65 spm; p = 0.010) and gross efficiency (13.4 ± 2.3% at 45 spm vs. 11.0 ± 1.6% at 65 spm; p = 0.012) was higher during de 45 spm condition than 65 spm in the 8-min. Respiratory exchange ratio (RER) presented a lower value at 4-min than at 8-min in 55 spm (4-min, 0.950 ± 0.065 vs. 8-min, 0.964 ± 0.053) and 65 spm cadences (4-min, 0.951 ± 0.030 vs. 8-min, 0.992 ± 0.047; p < 0.05). VO2, HR, lactate, and RPE were lower (p < 0.05) at 45 spm (VO2, 34.4 ± 6.0 mL·kg-1·min-1; HR, 161.2 ± 16.4 beats·min-1; lactate, 3.5 ± 1.0 mmol·l-1; RPE, 6.0 ± 2.1) than at 55 spm (VO2, 38.6 ± 5.2 mL·kg-1·min-1; HR, 168.1 ± 15.1 beats·min-1; lactate, 4.2 ± 1.2 mmol·l-1; RPE, 6.9 ± 1.4) and 65 spm (VO2, 38.7 ± 5.9 mL·kg-1·min-1; HR, 170.7 ± 13.0 beats·min-1; 5.3 ± 1.8 mmol·l-1; RPE, 7.6 ± 1.4) at 8-min. Moreover, lactate and RPE at 65 spm was greater than 55 spm (p < 0.05) at 8-min. Conclusion: International male SUP paddlers were most efficient and economical when paddling at 45 spm vs. 55 or 65 spm, confirmed by lower RPE values, which may likely translate to faster paddling speed and greater endurance.


Assuntos
Frequência Cardíaca/fisiologia , Consumo de Oxigênio/fisiologia , Oxigênio , Esforço Físico , Esportes Aquáticos , Adulto , Eficiência , Exercício Físico/fisiologia , Teste de Esforço , Humanos , Lactatos/sangue , Masculino , Pessoa de Meia-Idade , Respiração , Esportes Aquáticos/fisiologia
18.
Respir Res ; 21(1): 198, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32723327

RESUMO

The novel coronavirus disease 2019 (COVID-19) pandemic is a global crisis, challenging healthcare systems worldwide. Many patients present with a remarkable disconnect in rest between profound hypoxemia yet without proportional signs of respiratory distress (i.e. happy hypoxemia) and rapid deterioration can occur. This particular clinical presentation in COVID-19 patients contrasts with the experience of physicians usually treating critically ill patients in respiratory failure and ensuring timely referral to the intensive care unit can, therefore, be challenging. A thorough understanding of the pathophysiological determinants of respiratory drive and hypoxemia may promote a more complete comprehension of a patient's clinical presentation and management. Preserved oxygen saturation despite low partial pressure of oxygen in arterial blood samples occur, due to leftward shift of the oxyhemoglobin dissociation curve induced by hypoxemia-driven hyperventilation as well as possible direct viral interactions with hemoglobin. Ventilation-perfusion mismatch, ranging from shunts to alveolar dead space ventilation, is the central hallmark and offers various therapeutic targets.


Assuntos
Betacoronavirus , Infecções por Coronavirus/complicações , Hipóxia/etiologia , Pulmão/fisiopatologia , Consumo de Oxigênio/fisiologia , Pandemias , Pneumonia Viral/complicações , Insuficiência Respiratória/complicações , Infecções por Coronavirus/epidemiologia , Estado Terminal , Humanos , Hipóxia/metabolismo , Hipóxia/fisiopatologia , Pneumonia Viral/epidemiologia , Insuficiência Respiratória/metabolismo , Insuficiência Respiratória/fisiopatologia
19.
Am J Physiol Regul Integr Comp Physiol ; 319(3): R315-R322, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32697652

RESUMO

During exhaustive ramp-incremental cycling tests, the incidence of O2 uptake (V̇o2) plateaus is low. To verify the attainment of maximum V̇o2 (V̇o2max), it is recommended that a trial at a power output (PO) corresponding to 110% of the ramp-derived peak (POpeak) is performed. It remains unclear whether verification trials set at this PO can be tolerated for long enough to allow attainment of V̇o2max. Eleven recreationally trained individuals performed five ramp tests of varying slope (5, 10, 15, 25, and 30 W/min), each followed, in series, by two verification trials: the first at 110% POpeak of the 25 W/min ramp and the second at 110% POpeak attained in the preceding ramp test. Exercise duration of the first verification trial was on average 81 ± 15 s (CV = 9 ± 3%) versus 162 ± 32, 121 ± 24, 103 ± 15, and 73 ± 10 s for the second verification trials at 110% of POpeak of the 5, 10, 15, and 30 W/min ramp tests, respectively (P < 0.05). Compared with the highest V̇o2 recorded during ramp tests, V̇o2 from the subsequent verification trials was not different for the 5, 10, and 15 W/min ramp tests (P > 0.05) but was lower for the 25 and 30 W/min ramp tests (P < 0.05). Verification trials at 110% POpeak of rapidly incrementing ramp tests (i.e., 25 W/min) were not sustained for long enough to allow the attainment of V̇o2max. With commonly used rapidly incrementing ramp tests engendering exhaustion within 8-12 min, verification trials less than POpeak should be preferred as they can be sustained sufficiently long to allow the attainment of V̇o2max.


Assuntos
Transporte Biológico/fisiologia , Exercício Físico/fisiologia , Consumo de Oxigênio/fisiologia , Esforço Físico/fisiologia , Adulto , Teste de Esforço/métodos , Frequência Cardíaca/fisiologia , Humanos , Masculino
20.
Artigo em Inglês | MEDLINE | ID: mdl-32698542

RESUMO

The literature suggests that acute hypobaric (HH) and normobaric (NH) hypoxia exposure elicits different physiological responses. Only limited information is available on whether maximal cardiorespiratory exercise test outcomes, performed on either the treadmill or the cycle ergometer, are affected differently by NH and HH. A focused literature review was performed to identify relevant studies reporting cardiorespiratory responses in well-trained male athletes (individuals with a maximal oxygen uptake, VO2max > 50 mL/min/kg at sea level) to cycling or treadmill running in simulated acute HH or NH. Twenty-one studies were selected. The exercise tests in these studies were performed in HH (n = 90) or NH (n = 151) conditions, on a bicycle ergometer (n = 178) or on a treadmill (n = 63). Altitudes (simulated and terrestrial) varied between 2182 and 5400 m. Analyses (based on weighted group means) revealed that the decline in VO2max per 1000 m gain in altitude was more pronounced in acute NH vs. HH (-7.0 ± 1.4% vs. -5.6 ± 0.9%). Maximal minute ventilation (VEmax) increased in acute HH but decreased in NH with increasing simulated altitude (+1.9 ± 0.9% vs. -1.4 ± 1.8% per 1000 m gain in altitude). Treadmill running in HH caused larger decreases in arterial oxygen saturation and heart rate than ergometer cycling in acute HH, which was not the case in NH. These results indicate distinct differences between maximal cardiorespiratory responses to cycling and treadmill running in acute NH or HH. Such differences should be considered when interpreting exercise test results and/or monitoring athletic training.


Assuntos
Altitude , Exercício Físico/fisiologia , Hipóxia/fisiopatologia , Consumo de Oxigênio/fisiologia , Oxigênio/metabolismo , Teste de Esforço , Humanos , Masculino , Respiração
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