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1.
Adv Exp Med Biol ; 1232: 105-112, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893401

RESUMO

BACKGROUND: We have repeatedly observed a right-left asymmetry (RLA) of prefrontal cerebral oxygenation of subjects during the resting state. AIM: To clarify if the RLA is a reliably observable phenomenon at the group level and whether it is associated with systemic physiology, absolute tissue oxygen saturation (StO2) or total hemoglobin concentration ([tHb]). MATERIAL AND METHODS: StO2 and [tHb] values at the right and left prefrontal cortex (PFC) were calculated for two 5- min resting phases based on data from 76 single measurements (24 healthy adults, aged 22.0 ± 6.4 years). StO2 and [tHb] were measured with an ISS OxiplexTS frequency domain near-infrared spectroscopy device. In addition, end-tidal CO2 (PETCO2), heart rate (HR), respiration rate (RR) and the pulse-respiration quotient (PRQ = HR/RR) were measured and analyzed for the two phases. RESULTS: On the group level it was found that i) StO2 was higher at the right compared to the left PFC (for both phases), ii) RLA of StO2 (∆StO2 = StO2 (right)-StO2 (left) was independent of PETCO2, HR and PRQ, and iii) ∆StO2 was associated with absolute StO2 and [tHb] values (positively and negatively, respectively). DISCUSSION AND CONCLUSION: This study shows that i) RLA of StO2 at the PFC is a real phenomenon, and that ii) ∆StO2 at the group level does not depend on PETCO2, HR, RR or PRQ, but on absolute StO2 and [tHb]. We conclude that the RLA is a real effect, independent of systemic physiology, and most likely reflects genuine properties of the brain, i.e. different activity states of the two hemispheres.


Assuntos
Hemoglobinas , Oxigênio , Córtex Pré-Frontal , Espectroscopia de Luz Próxima ao Infravermelho , Adolescente , Adulto , Hemoglobinas/metabolismo , Humanos , Oxigênio/metabolismo , Consumo de Oxigênio , Córtex Pré-Frontal/metabolismo , Adulto Jovem
2.
Adv Exp Med Biol ; 1232: 193-199, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893410

RESUMO

Measurement of oxyhemoglobin (O2Hb) changes in the cerebral cortex using near-infrared spectroscopy (NIRS) shows that its levels increase during moderate-intensity exercise and persists after exercise. However, the effects of exercise duration on O2Hb persistence in the premotor cortex (PMC) are unknown. We aimed to determine the effects of exercise duration on the persistence of O2Hb changes after moderate-intensity cycling as exercise. Healthy young volunteers were recruited to participate in this study. After a 3-min rest period, the exercise was initiated at a workload corresponding to 50% VO2peak. The exercise continued for 10 min and 20 min, followed by 15 min of rest. The O2Hb levels in the right (R-PMC) and left premotor cortices (L-PMC) were measured using an NIRS system. The O2Hb values during the 15-min post-exercise rest period in the R-PMC were 0.010 ± 0.011 mM·cm after the 10-min exercise and 0.035 ± 0.010 mM·cm after the 20-min exercise, without significant differences (p = 0.104). The O2Hb value in the L-PMC during post-exercise rest (0.055 ± 0.010 mM·cm) after the 20-min exercise was significantly higher than that after the 10-min exercise (0.023 ± 0.007 mM·cm; p = 0.014). Thus, the effects of exercise duration on O2Hb persistence have laterality in the PMC.


Assuntos
Exercício , Córtex Motor , Consumo de Oxigênio , Oxiemoglobinas , Espectroscopia de Luz Próxima ao Infravermelho , Adulto , Feminino , Humanos , Masculino , Córtex Motor/metabolismo , Oxiemoglobinas/metabolismo , Fatores de Tempo , Adulto Jovem
3.
Adv Exp Med Biol ; 1232: 201-207, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893411

RESUMO

Our previous research confirmed that patients with malignant hematopoietic disease already had a low hemoglobin level before allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, no study has determined whether a correlation exists between exercise load, hemoglobin level, and muscle oxygen saturation (SmO2), during exercise. Therefore, the purpose of this study was to investigate whether near-infrared spectroscopy (NIRS)-derived SmO2 is associated with exercise load, as determined by a dynamometer, before allo-HSCT. This study included 19 male patients who received allo-HSCT in Hyogo College of Medicine Hospital (Japan) between November 2009 and October 2012. Patients performed isometric repeated dorsiflexion at 50% maximum voluntary contraction for 180 s to determine exercise load, and SmO2 was evaluated during exercise at the same time using NIRS (BOM-L1TRW, Omega Wave, Inc., Japan). The hemoglobin level was also evaluated before allo-HSCT. Patients with hematopoietic disease before allo-HSCT already had a low hemoglobin level. There was a significant correlation between exercise load and ∆SmO2; however, the hemoglobin level was not correlated with exercise load. In these patients, exercise load might be affected by muscle oxygen consumption rather than by the hemoglobin level. This finding shows that NIRS can used to assess fatigue in patients with malignant hematopoietic disease.


Assuntos
Exercício , Doenças Hematológicas , Neoplasias Hematológicas , Hemoglobinas , Músculo Esquelético , Consumo de Oxigênio , Doenças Hematológicas/metabolismo , Doenças Hematológicas/fisiopatologia , Neoplasias Hematológicas/metabolismo , Neoplasias Hematológicas/fisiopatologia , Hemoglobinas/metabolismo , Humanos , Japão , Masculino , Músculo Esquelético/metabolismo , Oxigênio/metabolismo
4.
Adv Exp Med Biol ; 1232: 209-214, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893412

RESUMO

Cognitive function is reported to improve by moderate aerobic exercise. However, the effects of intermittent exercise with rest between the moderate-intensity exercise are unclear. Therefore, this study aimed to compare the effects of continuous and intermittent exercise on cerebral oxygenation and cognitive function. This study included 18 healthy adults. For the continuous exercise protocol, 5 min of rest was followed by 30 min of exercise; 5 min of rest was allowed after each exercise. For the intermittent exercise protocol, 3 sets of 10 min of exercise were completed, with 5 min of rest between the sets. Exercise intensity was 50% of maximum oxygen uptake. Oxyhemoglobin (O2Hb) in the prefrontal cortex (PFC) was measured during each protocol, and cognitive tasks (Stroop test) were performed before and after exercise. O2Hb levels for the left and right PFCs were significantly higher post-exercise than pre-exercise for both exercise protocols (p < 0.01). The average reaction time in the Stroop test was significantly shorter post-exercise than pre-exercise for both protocols (p < 0.01). There was no significant difference in the error rate pre- and post-exercise for both protocols (continuous p = 0.22; intermittent p = 0.44). There was no significant difference between both protocols in all measurement results (O2Hb: p = 0.67; average reaction time p = 0.50; error rate p = 0.24). O2Hb was higher and average reaction time was shorter after exercise than before exercise for both exercise protocols. Intermittent and continuous exercise may improve cognitive function to the same degree after exercise.


Assuntos
Cérebro , Cognição , Exercício , Oxigênio , Espectroscopia de Luz Próxima ao Infravermelho , Adulto , Cérebro/metabolismo , Cognição/fisiologia , Humanos , Oxigênio/metabolismo , Consumo de Oxigênio
5.
Adv Exp Med Biol ; 1232: 223-229, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893414

RESUMO

The aim of this study was to compare muscle O2 dynamics during exercise between aerobic capacity-matched overweight and normal-weight adults. Overweight women (OW, n = 9) and normal-weight women (NW, n = 14) performed graded treadmill exercise until exhaustion. Muscle O2 saturation (SmO2) and relative changes from rest in deoxygenated hemoglobin concentration (∆deoxy-Hb) and total hemoglobin concentration (∆total-Hb) were monitored continuously at gastrocnemius medialis muscle by near infrared spatial resolved spectroscopy. Significantly higher SmO2 and lower ∆deoxy-Hb and ∆total-Hb were observed in OW compared with NW. Pulmonary O2 uptake (VO2) normalized by fat-free mass was matched between groups. In both groups, peak VO2 was significantly correlated with change in SmO2 and ∆deoxy-Hb. Our findings suggest that both muscle blood volume and deoxygenation were lower in overweight adults, compared to aerobic capacity-matched normal-weight adults. Moreover, lowered muscle O2 extraction was related to peak VO2 in overweight adults, as well as in normal-weight adults.


Assuntos
Exercício , Músculo Esquelético , Sobrepeso , Consumo de Oxigênio , Adulto , Teste de Esforço , Feminino , Hemoglobinas , Humanos , Músculo Esquelético/metabolismo , Sobrepeso/metabolismo
6.
Adv Exp Med Biol ; 1232: 231-237, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893415

RESUMO

Near-infrared spectroscopy (NIRS) during cardiopulmonary exercise test (CPX) has shown a correlation between prefrontal cortex (PFC) oxygenated hemoglobin (O2Hb) level and negative affective responses. We hypothesized that O2Hb changes differ between the PFC and motor-related areas. This study investigated changes in hemoglobin levels in the PFC and motor-related areas during CPX. Twelve young healthy adults participated in this study. They performed a CPX after 4 min of rest and 4 min of warming up. Cortical O2Hb, deoxygenated hemoglobin (HHb), and total hemoglobin (THb) levels were measured with NIRS during CPX. Regions of interest (ROI) were the PFC, premotor area (PMA), supplementary motor area (SMA), and primary motor cortex (M1). The anaerobic threshold (AT), respiratory compensation (RC), and peak oxygen uptake (Peak) points were determined. The rest, AT, RC and Peak points of O2Hb, HHb, and THb were averaged over 5 s; hemoglobin slopes, from RC to the Peak points, were calculated to compare functional changes in cortical oxygenation. Average values of O2Hb, HHb, and THb in each ROI were compared among the rest, AT, RC, and Peak points. Average values of hemoglobin slopes, from RC to Peak points, were compared among ROIs using Bonferroni multiple comparisons. The HHb of all ROIs significantly increased at Peak point, compared with at the AT point. THb of the PFC, PMA, and SMA significantly increased at the RC or Peak points, compared with at the rest point. Hemoglobin slopes, from RC to Peak, showed no significant differences among ROIs. Each ROI exhibited similar changes, regardless of cortical function.


Assuntos
Córtex Motor , Oxigênio , Córtex Pré-Frontal , Espectroscopia de Luz Próxima ao Infravermelho , Adulto , Teste de Esforço , Feminino , Humanos , Masculino , Córtex Motor/metabolismo , Oxigênio/metabolismo , Consumo de Oxigênio , Oxiemoglobinas/metabolismo , Córtex Pré-Frontal/metabolismo , Adulto Jovem
7.
Adv Exp Med Biol ; 1232: 239-244, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893416

RESUMO

Near-infrared time-resolved spectroscopy (NIRTRS) can quantitatively evaluate mean optical path length (MPL). Since an increase in optical absorbers in the NIR region (e.g. an increase in deoxygenated hemoglobin during exercise) would shorten the MPL, the NIRS measurement area may vary depending on physical and physiological characteristics of the measurement region and/or the exercise intensity. The aim of this study was to examine the changes in MPL measured by NIRTRS during ramp cycling exercise between fat layer thickness-matched subjects with different aerobic capacities. Healthy control (CON, n = 8) and endurance-trained males (TR, n = 8) performed ramp cycling exercise until exhaustion. Deoxygenated hemoglobin concentration (Deoxy-Hb), total hemoglobin concentration (Total-Hb) and oxygenated hemoglobin concentration (Oxy-Hb) were evaluated by a three-wavelength NIRTRS system. MPL in each wavelength (MPL760, MPL800 and MPL830) was monitored continuously. With increasing exercise intensity, Total- and Deoxy-Hb significantly increased and Oxy-Hb decreased in both groups. Total- and Oxy-Hb during exercise were significantly higher in TR than CON (P < 0.05, P < 0.01, respectively). Furthermore, Deoxy-Hb also tended to be higher in TR than CON (P = 0.07). In addition, MPL at all wavelengths significantly shortened with an increase in exercise intensity, with no differences between CON and TR. In particular, MPL760 at peak exercise shortened more than 10% compared to the start of exercise in both groups, even though MPL830 decreased only a few per cent. These findings suggest that the NIRS measurement area may be reduced during ramp cycling exercise due to shortened MPL. Additionally, the changes in MPL may be especially greater at 760 nm than at the other wavelengths due to greater changes in Deoxy-Hb during exercise. Furthermore, this study indicates that the measurements of muscle deoxygenation using continuous-wave NIRS can be less accurate since they are significantly affected by changes in the optical path length.


Assuntos
Exercício , Consumo de Oxigênio , Músculo Quadríceps , Adolescente , Adulto , Estudos de Casos e Controles , Teste de Esforço , Humanos , Masculino , Oxigênio/metabolismo , Oxiemoglobinas/metabolismo , Músculo Quadríceps/metabolismo , Espectroscopia de Luz Próxima ao Infravermelho , Adulto Jovem
8.
Adv Exp Med Biol ; 1232: 245-251, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893417

RESUMO

Skeletal muscle metabolic function is known to respond positively to endurance exercise interventions, such as marathon training. Studies investigating skeletal muscle have typically used muscle biopsy samples or magnetic resonance spectroscopy (MRS) to interrogate metabolic function. We aimed to non-invasively detect exercise-training-induced improvements in muscle function using broadband near-infrared spectroscopy (NIRS). We used NIRS to determine concentration changes in oxygenated haemoglobin (HbO2) and the oxidation state of cytochrome-c-oxidase (oxCCO) in gastrocnemius during arterial occlusion in 14 volunteers. We also used a cardio-pulmonary exercise test (CPET) to assess peak total body oxygen uptake (peakVO2; a measure of fitness). Measurements were made at baseline (BL) which was prior to a period of at least 16 weeks of training for the 2017 London Marathon, and then within 3 weeks after completion of the marathon, follow-up (FU). We observed an increase in locally measured muscle oxygen consumption and rate of oxCCO concentration change, but not in cardio-respiratory fitness measured as whole-body peak oxygen consumption (peakVO2).


Assuntos
Músculo Esquelético , Consumo de Oxigênio , Corrida , Espectroscopia de Luz Próxima ao Infravermelho , Adulto , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Humanos , Masculino , Músculo Esquelético/metabolismo , Oxiemoglobinas/metabolismo
9.
Adv Exp Med Biol ; 1232: 253-259, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893418

RESUMO

BACKGROUND: Near-infrared spectroscopy (NIRS) tissue oximeters enable non-invasive measurement of muscle oxygenation and perfusion. Several NIRS oximeters are currently available, particularly for muscle measurements. AIM: To evaluate the agreement of oxygenation and perfusion measurements obtained by two devices (Moxy, Fortiori Designs LLC, USA, and Nimo, Nirox, Italy) during an arterial occlusion test on the arm. SUBJECT AND METHODS: Arterial occlusions were conducted at the arm of one individual for 10 min with 200 mmHg. Measurements were made twice a day on five different days. Both NIRS devices were fixed at the arm (covering the muscles extensor carpi ulnaris, extensor digitorum, and flexor carpi ulnaris). RESULTS: The experiment revealed that i) both devices could detect changes in muscle oxygenation and perfusion during the occlusion, but ii) the magnitudes and dynamic changes differed between the two devices. DISCUSSION AND CONCLUSION: Both devices had different performances with regard to the measurement of tissue oxygenation and perfusion. This study shows that it might be worthwhile to compare all NIRS tissue oximeters currently available for muscle measurement in a large systematic study to increase the comparability of measurements obtained with different devices.


Assuntos
Oximetria , Oxigênio , Adulto , Humanos , Itália , Masculino , Músculo Esquelético/metabolismo , Oximetria/instrumentação , Oximetria/normas , Oxigênio/metabolismo , Consumo de Oxigênio , Espectroscopia de Luz Próxima ao Infravermelho
10.
Adv Exp Med Biol ; 1232: 331-337, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893428

RESUMO

Obesity, a risk factor of coronary artery disease, is known to cause peripheral microcirculatory disturbances. This study evaluated the relationship between the degree of obesity and peripheral microcirculatory disturbances, using peripheral near infrared spectroscopy (NIRS) with a vascular occlusion test (VOT). We compared correlations between the NIRS parameter changes induced by VOT and body mass index (BMI) in patients with and without statin therapy. A NIRS probe was set on the right thenar eminence, brachial artery blood flow was blocked for 3 min, and then released. Although total hemoglobin (ΔcHb), deoxyhemoglobin (ΔHHb) and tissue oxygenation index (ΔTOI) were not correlated with BMI, a significant negative correlation was found between oxyhemoglobin (ΔO2Hb) and BMI in the overall study population (r = -0.255, p-value 0.02). In addition, a significant negative correlation was found between ΔO2Hb and BMI in patients without statin therapy (r = -0.353, p-value 0.02) but not in patients with statin therapy (r = -0.181, p-value 0.27). These findings suggest that ΔO2Hb may be a useful indicator to assess peripheral microcirculation.


Assuntos
Índice de Massa Corporal , Doença da Artéria Coronariana , Espectroscopia de Luz Próxima ao Infravermelho , Idoso , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Microcirculação/fisiologia , Oxigênio , Consumo de Oxigênio , Oxiemoglobinas/metabolismo , Fatores de Risco , Espectroscopia de Luz Próxima ao Infravermelho/normas
11.
Int J Sports Med ; 41(1): 21-26, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31756737

RESUMO

The aim of the study was to verify the relative contributions of energetic and kinematic parameters to the performance in 400-m front crawl test. Fourteen middle-distance swimmers participated in the study. Oxygen consumption was measured directly and blood samples were collected to assay lactate concentration. Both oxygen consumption and lactate concentration were used to calculate the: (i) overall energy expenditure, (ii) anaerobic (alactic and lactic) and (iii) aerobic contributions. The mean centre of mass speed and intracycle velocity variation were determined through three-dimensional kinematic analysis. Mean completion time was 315.64±26.91s. Energetic contributions were as follows: 6.1±0.28% from alactic anaerobic metabolism, 5.9±0.63% from anaerobic lactic and 87.8±0.88% from aerobic. Mean intracycle velocity variation was 0.14±0.03. The results indicated that performance of 400-m test relies predominantly on aerobic power. Parameters such as lactate, mean speed, anaerobic lactic and alactic (kW) correlated with performance of 400-m test (p <0.05). Multiple linear regressions indicated that mean centre of mass speed and anaerobic alactic (kW) determined the 400-m test performance (R2=0.92). Even though the T400 is characterized by aerobic metabolism, the anaerobic alactic component cannot be negligible at this competition level.


Assuntos
Metabolismo Energético/fisiologia , Teste de Esforço/métodos , Natação/fisiologia , Fenômenos Biomecânicos/fisiologia , Comportamento Competitivo/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Oxigênio/sangue , Consumo de Oxigênio , Estudos de Tempo e Movimento , Gravação em Vídeo , Adulto Jovem
12.
Int J Sports Med ; 41(1): 36-43, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31747699

RESUMO

Subconcussive head impacts (SHI), defined as impacts to the cranium that do not result in concussion symptoms, are gaining traction as a major public health concern. The contribution of physiological factors such as physical exertion and muscle damage to SHI-dependent changes in neurological measures remains unknown. A prospective longitudinal study examined the association between physiological factors and SHI kinematics in 15 high school American football players over one season. Players wore a sensor-installed mouthguard for all practices and games, recording frequency and magnitude of all head impacts. Serum samples were collected at 12 time points (pre-season, pre- and post-game for five in-season games, and post-season) and were assessed for an isoenzyme of creatine kinase (CK-MM) primarily found in skeletal muscle. Physical exertion was estimated in the form of excess post-exercise oxygen consumption (EPOC) from heart rate data captured during the five games. Mixed-effect regression models indicated that head impact kinematics were significantly and positively associated with change in CK-MM but not EPOC. There was a significant and positive association between CK-MM and EPOC. These data suggest that when examining SHI, effects of skeletal muscle damage should be considered when using outcome measures that may have an interaction with muscle damage.


Assuntos
Futebol Americano/lesões , Cabeça/fisiopatologia , Músculo Esquelético/lesões , Esforço Físico/fisiologia , Adolescente , Fenômenos Biomecânicos , Concussão Encefálica/fisiopatologia , Creatina Quinase Forma MM/sangue , Futebol Americano/fisiologia , Humanos , Estudos Longitudinais , Masculino , Músculo Esquelético/enzimologia , Consumo de Oxigênio/fisiologia , Estudos Prospectivos , Estados Unidos
13.
J Sports Sci ; 38(1): 114-120, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31665975

RESUMO

Sedentary time (ST) has been inconsistently associated with adiposity and cardiorespiratory fitness in children in previous studies. We studied cross-sectional associations of ST, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) with fat mass index (FMI) and cardiorespiratory fitness (estimated VO2max). Associations were evaluated with and without considering pattern of ST by bout length. We measured ST and activity by a wrist-worn accelerometer, FMI by bioelectrical impedance, and VO2max by Pacer test in 443 children (51.2% girls, 10.2 ± 0.6 years). Isotemporal substitution regression models estimated the effects of substituting ST, LPA, and MVPA on FMI and VO2max. Further models repeated analyses separating ST into short (<10 min) and long (≥10 min) bouts. Only replacing ST or LPA with MVPA was consistently associated with lower FMI and greater VO2max. When separated by bout length, only one unique association was found where replacing long ST bouts with short ST bouts was associated with lower FMI in girls only. In conclusion, activity pattern is associated with adiposity in girls and fitness in boys and girls. Separating ST into long and short ST bouts may be of minimal importance when assessing associations with adiposity and fitness using wrist-worn accelerometry in children.


Assuntos
Acelerometria/instrumentação , Adiposidade/fisiologia , Aptidão Cardiorrespiratória , Exercício/fisiologia , Monitores de Aptidão Física , Comportamento Sedentário , Índice de Massa Corporal , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Fatores de Tempo
14.
Sports Health ; 12(1): 80-87, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31710819

RESUMO

BACKGROUND: The prevalence of musculoskeletal (MSK) conditions is increasing, and although current guidelines for physical activity attempt to combat this, many fail to achieve the recommended targets. The present study sought to investigate whether regular tennis participation is more effective at enhancing MSK function than meeting the current international physical activity guidelines. HYPOTHESIS: Tennis players will display significantly enhanced MSK function when compared with age-matched healthy active nonplayers. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: Ninety participants (age range, 18-65 years) took part in this study; there were 43 tennis players (18 men, 25 women) and 47 nonplayers (26 men, 21 women). MSK function was assessed by cluster analysis of 3 factors: (1) electromyographic fatigability of prime movers during handgrip, knee extension, and knee flexion; (2) isometric strength in the aforementioned movements; and (3) body composition measured by bioelectrical impedance analysis. Maximal oxygen uptake was also assessed to characterize cardiorespiratory fitness. RESULTS: Tennis players displayed significantly greater upper body MSK function than nonplayers when cluster scores of body fat percentage, handgrip strength, and flexor carpi radialis fatigue were compared by analysis of covariance, using age as a covariate (tennis players, 0.33 ± 1.93 vs nonplayers, -0.26 ± 1.66; P < 0.05). Similarly, tennis players also demonstrated greater lower extremity function in a cluster of body fat percentage, knee extension strength, and rectus femoris fatigue (tennis players, 0.17 ± 1.76 vs nonplayers, -0.16 ± 1.70; P < 0.05). CONCLUSION: The present study offers support for improved MSK functionality in tennis players when compared with age-matched healthy active nonplayers. This may be due to the hybrid high-intensity interval training nature of tennis. CLINICAL RELEVANCE: The findings suggest tennis is an excellent activity mode to promote MSK health and should therefore be more frequently recommended as a viable alternative to existing physical activity guidelines.


Assuntos
Músculo Esquelético/fisiologia , Tênis/fisiologia , Adolescente , Adulto , Idoso , Composição Corporal , Aptidão Cardiorrespiratória/fisiologia , Análise por Conglomerados , Estudos Transversais , Feminino , Força da Mão , Humanos , Joelho/fisiologia , Masculino , Pessoa de Meia-Idade , Fadiga Muscular/fisiologia , Força Muscular/fisiologia , Consumo de Oxigênio/fisiologia , Adulto Jovem
15.
Waste Manag ; 102: 1-11, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31654874

RESUMO

Goal of the work was to compare the respiration activities, as measured via oxygen consumption with three different organic waste stability methods so that to propose the optimal one. The novelty of the work is that there exists no comparison of solid-phase with liquid-phase stability assessment techniques in the literature. The respiration activities were assessed using two solid-phase methods and a manometric liquid-phase method (MANLIQ) performed on twenty-seven organic substrates. The methods rely on measuring oxygen consumption (uptake) via pressure drops (liquid-phase test, static solid-phase test) or via direct O2 measurements on the gaseous phases at the inlet and outlet of the respirometer (solid-phase dynamic test). A positive statistically significant correlation was calculated between the MANLIQ and the static solid-phase indices. The maximum rate MANLIQ index for the raw substrates was 2900 mg O2 kg-1 VS h-1, while most of the processed substrates had cumulative MANLIQ indices below 160 g O2 kg-1 VS. The ratio of the liquid indices to the static solid-phase indices ranged from 1.6 to 2.7 and the ratio of the liquid indices to the dynamic solid-phase indices ranged from 0.2 to 0.4. The MANLIQ method failed to result in a good correlation of the processing time with the respiration indices. On the other hand, a correlation was more visible in the two solid-phase tests, despite the large variability of the types and sources of the substrates. Therefore, the solid-phase methods should be preferred over the liquid-phase method to assess stability for various organic substrates.


Assuntos
Consumo de Oxigênio , Microbiologia do Solo
16.
Chemosphere ; 240: 124974, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726613

RESUMO

In this research, the continuous physiological changes of zebrafish (Danio rerio) in 0.1 µg/L thallium (Tl) in 15 days were investigated. The results showed that Tl(I) stress had a significant positive linear correlation with zebrafish ammonia nitrogen excretion (ANE) (p < 0.001), and the mean value of ANE in Tl(I) treatment (435 ±â€¯227 mg/kg/h) was approximately 2 times higher than in the control group (239 ±â€¯168 mg/kg/h), which suggested that ANE was suitable for Tl(I) stress assessment. A substantial difference based on oxygen consumption rate (OCR) between the control group (587 ±â€¯112 mg/kg/h) and Tl(I) treatment (260 ±â€¯88 mg/kg/h) with a high significance p < 0.001 could be observed, and the results indicated that Tl(I) played a negative role in OCR of zebrafish. The characteristics of both ANE and OCR changes under slight Tl(I) stress could be reflected by the ammonia quotient (AQ). It was noteworthy that AQ increased rapidly in first 6 h from 0.66 to 4.50, which was 3 times higher than 1.2, indicating rapid increase in both anaerobic energy utilization and protein metabolism in 0.1 µg/L Tl(I) exposure. It is concluded that the physiological changes of zebrafish based on metabolism can be regarded as a sensitive biological indicator of Tl(I) pollution, which could work as a substitute of potassium that disrupts the normal biological metabolism in the process of transport.


Assuntos
Tálio/toxicidade , Peixe-Zebra/metabolismo , Amônia/metabolismo , Animais , Cinética , Nitrogênio/metabolismo , Consumo de Oxigênio/fisiologia , Fatores de Tempo , Peixe-Zebra/fisiologia
17.
Braz J Med Biol Res ; 52(12): e9169, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31826183

RESUMO

We investigated the effect of caffeine ingestion combined with a 2-wk sprint interval training (SIT) on training-induced reductions in body adiposity. Twenty physically-active men ingested either 5 mg/kg of cellulose as a placebo (PLA, n=10) or 5 mg/kg of caffeine (CAF, n=10) 60 min before each SIT session (13×30 s sprint/15 s of rest). Body mass and skinfold thickness were measured pre- and post-training. Energy expenditure was measured at rest, during exercise, and 45 min after exercise in the first SIT session. Body fat was similar between PLA and CAF groups at pre-training (P>0.05). However, there was a significant decrease in body fat after training in the CAF group (-5.9±4.2%, P<0.05) but not in PLA (1.5±8.0%, P>0.05). There was no difference in energy expenditure at rest and during exercise between PLA and CAF groups (P>0.05), but the post-exercise energy expenditure was 18.3±21.4% greater in the CAF than in the PLA group (P<0.05). In conclusion, caffeine ingestion before SIT sessions induced a body fat loss that may be associated with higher post-exercise energy expenditure.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Cafeína/administração & dosagem , Metabolismo Energético/efeitos dos fármacos , Treinamento Intervalado de Alta Intensidade , Consumo de Oxigênio/efeitos dos fármacos , Adulto , Método Duplo-Cego , Humanos , Masculino , Adulto Jovem
18.
Diving Hyperb Med ; 49(4): 266-275, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31828745

RESUMO

INTRODUCTION: The purpose of the study was to evaluate the thermal protection provided by a 2-3 mm surfing wet suit during at least two hours of fin diving in shallow water with a temperature of 16-20°C. We examined the effect of wearing the suit while diving in cold water on cognitive performance, muscle strength, and hand motor function. METHODS: Subjects were six male well-trained rebreather divers, 19-23 years old, acclimatised to cold. They attended the laboratory on three separate occasions, when we conducted the experiment at one of three temperatures, 16, 18, and 20°C. Core temperature (gastrointestinal system), skin temperature, oxygen consumption, and cold perception were evaluated during the test. Before and immediately after the dives, subjects performed a series of cognitive, manual dexterity, and muscle strength tests. RESULTS: Core temperature decreased by 0.35-0.81°C over the two hours at all three water temperatures. No subject reached a core temperature below 35°C. The decrease in upper body skin temperature during the two hour dive ranged between 5.97 and 8.41°C (P < 0.05). Two hours diving in 16-20°C water resulted in a significant increase in the time taken to perform the task of unlinking and reassembling four shackles (∼30% longer, P < 0.05). No effect was found on the cognitive or muscle strength tests. CONCLUSIONS: A 2-3 mm wet suit provides adequate thermal protection in trained and cold-acclimatised young males engaged in active diving in shallow water with a temperature of 16°C and above.


Assuntos
Cognição/fisiologia , Temperatura Baixa , Mergulho , Força Muscular/fisiologia , Roupa de Proteção , Regulação da Temperatura Corporal , Mergulho/fisiologia , Mãos/fisiologia , Força da Mão/fisiologia , Humanos , Masculino , Destreza Motora/fisiologia , Consumo de Oxigênio , Temperatura Ambiente , Água
19.
Croat Med J ; 60(5): 449-457, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31686459

RESUMO

AIM: To assess whether the simultaneous performance of exercise stress echocardiography and cardio-pulmonary testing (ESE-CPET) may facilitate the timely diagnosis of subclinical left ventricular diastolic dysfunction (LVDD) in patients with non-severe chronic obstructive pulmonary disease (COPD), preserved left ventricular systolic function, and exertional dyspnea or exercise intolerance. METHODS: This cross-sectional study, conducted between May 2017 and April 2018, involved 104 non-severe COPD patients with exertional dyspnea and preserved ejection fraction who underwent echocardiography before CPET and 1-2 minutes after peak exercise. Based on the peak E/e' ratio, patients were divided into the group with stress-induced LVDD - E/e'>15 and the group without stress-induced LVDD. We assessed the association between LVDD and the following CPET variables: minute ventilation, peak oxygen uptake (VO2), ventilatory efficiency, heart rate reserve, and blood pressure. RESULTS: During ESE-CPET, stress-induced LVDD occurred in 67/104 patients (64%). These patients had lower work load, peak VO2, O2 pulse, and minute ventilation (VE), and higher VE/VCO2 slope than patients without stress-induced LVDD (35.18±10.4 vs 37.01±11.11, P<0.05). None of the CPET variables correlated with E/e'. CONCLUSION: Combined ESE-CPET may distinguish masked LVDD in patients with non-severe COPD with exertional dyspnea and preserved left ventricular systolic function. None of the CPET variables was a predictor for subclinical LVDD.


Assuntos
Ecocardiografia sob Estresse , Doença Pulmonar Obstrutiva Crônica , Disfunção Ventricular Esquerda , Estudos Transversais , Humanos , Consumo de Oxigênio , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Esquerda/diagnóstico por imagem
20.
J Sports Med Phys Fitness ; 59(10): 1601-1607, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31694361

RESUMO

BACKGROUND: Outdoor exercise often proceeds in rainy conditions. However, there are very few studies reporting the physiological effects of cold with rain or wet-cold exposure on humans during exercise. The purpose of this study was to investigate the effects of rain on physiological responses during running exercise at 80% V̇Omax in the cold. METHODS: Twelve healthy men (age: 21.7±3.3 years; height: 1.760±0.085 m; body weight: 68.8±7.1 kg; maximal oxygen consumption: 67.3±5.00 mL/kg/min) exercised on a treadmill at 80% V̇Omax intensity for 60 minutes with rain (RAIN) or not (CON) at 5 °C. RESULTS: Rectal temperature was significantly lower in RAIN than in CON at 10, 40, 50, and 60 minutes (P<0.05). Mean weighted skin temperature was significantly lower in RAIN than in CON during exercise (P<0.05). Oxygen consumption and rating of perceived exertion were significantly higher in RAIN than in CON at 50 and 60 minutes (P<0.05). Plasma lactate was significantly higher in RAIN than in CON at 10 minutes and from 40 to 60 minutes (P<0.05). Plasma norepinephrine levels were significantly higher in RAIN than in CON at 10 minutes and from 40 to 60 minutes (P<0.05). CONCLUSIONS: These results suggest that rain increased heat loss during the early phase of exercise in the cold, then heat production increased and transiently suppressed cold stress. However, with time, body heat loss intensified due to increasing wet area, and then energy expenditure and plasma lactate increased due to cold stress. Therefore, rain may decrease exercise performance and affect sport safety.


Assuntos
Temperatura Baixa/efeitos adversos , Metabolismo Energético/fisiologia , Chuva , Corrida/fisiologia , Adolescente , Adulto , Regulação da Temperatura Corporal/fisiologia , Estudos de Casos e Controles , Teste de Esforço/métodos , Humanos , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio/fisiologia , Temperatura Cutânea , Adulto Jovem
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