Rhabdomyolysis in adolescents with mental disorders during treatment： two cases report / 四川精神卫生

This article analyzed the laboratory indicators during the clinical diagnosis and treatment of two adolescents with mental disorders who developed rhabdomyolysis during hospitalization， so as to explore the risk of rhabdomyolysis occurring after mild to moderate exercise during treatment for adolescent with mental disorders and to provide references for clinical diagnosis and treatment.

The effect of varied exercise intensity on antioxidant function, aortic endothelial function, and serum lipids in rats with non-alcoholic fatty liver disease / El efecto del ejercicio de intensidad variada sobre la función antioxidante, la función endotelial aórtica y los lípidos séricos en ratas con enfermedad del hígado graso no alcohólico

Abstract This study aimed to compare the effects of diet and exercise of different intensities on antioxidant function, aortic endothelial cell function and serum lipids in NAFLD (nonalcoholic fatty liver disease) rats. Fifty Sprague-Dawley (SD) rats (180-220g) were randomly divided into two experimental groups and fed either a standard rodent chow diet (CON; n=10) or a high-fat diet (HFD; n=40). After 16 weeks, the animals that received the HFD were randomly separated into a high-fat control group (HFC; n=10) or three exercise training groups: HFD and low-intensity exercise (LE; n=10), HFD and moderate-intensity exercise (ME; n=10), and HFD and incremental intensity exercise (IE; n=10). These experimental rats keep sedentary or trained for the next six weeks. A detection kit was used to detect nitric oxide synthase (NOs), nitric oxide (NO), malondialdehyde (MDA) and other markers of aortic oxidative stress. The expression levels of endothelial nitric oxide synthase (e-NOS) and endothelin-1 (ET-1) were detected by immunohistochemistry. TC, TG, and other lipid metabolism parameters were detected by an automatic analyzer. Exercise with different intensities could improve lipid metabolism, enhance antioxidant function, reduce MDA (P<0.01), increase NO (P<0.01), and improve the expression of e-NOS and ET-1 (P<0.01) protein levels in NAFLD rats. Decreased blood lipids were exhibited in all exercise groups. Notably, the moderate-intensity exercise demonstrated more effect on increasing glutathione (GSH) contents (P<0.01) and decreased the expression of ET-1 protein levels (P<0.01). The results showed that exercise at different intensities improved lipid metabolism and enhanced anti-oxidation function. Moderate exercise could improve the function of aortic endothelial cells.

Resumen Este estudio tuvo como objetivo comparar los efectos de la dieta y el ejercicio a diferentes intensidades sobre la función antioxidante, la función de las células endoteliales aórticas y los lípidos séricos en ratas NAFLD (con enfermedad del hígado graso no alcohólico) y alimentados con una dieta estándar para roedores (CON; n = 10) o con una dieta alta en grasas (HFD; n = 40). Después de 16 semanas, los animales que recibieron HFD se separaron aleatoriamente en un grupo de control alto en grasas (HFC; n=10) o tres grupos de entrenamiento físico: HFD y ejercicio de baja intensidad (LE; n=10), HFD y ejercicio de intensidad moderada (ME; n=10), y HFD y ejercicio de intensidad incremental (IE; n=10). Estas ratas experimentales se mantuvieron sedentarias o entrenadas durante las próximas seis semanas. Se utilizó un kit de detección para determinar óxido nítrico sintetasa (NO), óxido nítrico (NO), malondialdehído (MDA) y otros marcadores de estrés oxidativo aórtico. Los niveles de expresión de la óxido nítrico sintetasa endotelial (e-NOS) y endotelina-1 (ET-1) se detectaron mediante inmunohistoquímica. El analizador automático detectó TC, TG y otros parámetros del metabolismo de los lípidos. El ejercicio con diferente intensidad mejoró el metabolismo de los lípidos, mejoró la función antioxidante, redujo la MDA (P <0,01), aumentó el NO (P <0,01) y mejoró la expresión de los niveles de proteína e-NOS y ET-1 (P <0,01) en ratas NAFLD. Se observó una disminución de los lípidos en sangre en todos los grupos de ejercicio. En particular, el ejercicio de intensidad moderada demostró un mayor efecto en el aumento del contenido de glutatión (GSH) (P<0,01) y disminuyó la expresión de los niveles de proteína ET-1 (P<0,01). Los resultados mostraron que el ejercicio a diferentes intensidades mejoró el metabolismo de los lípidos y mejoró función antioxidante. El ejercicio moderado podría mejorar la función de las células endoteliales aórticas.

Reviewing physical exercise in non-obese diabetic Goto-Kakizaki rats

There is a high incidence of non-obese type 2 diabetes mellitus (non-obese-T2DM) cases, particularly in Asian countries, for which the pathogenesis remains mainly unclear. Interestingly, Goto-Kakizaki (GK) rats spontaneously develop insulin resistance (IR) and non-obese-T2DM, making them a lean diabetes model. Physical exercise is a non-pharmacological therapeutic approach to reduce adipose tissue mass, improving peripheral IR, glycemic control, and quality of life in obese animals or humans with T2DM. In this narrative review, we selected and analyzed the published literature on the effects of physical exercise on the metabolic features associated with non-obese-T2DM. Only randomized controlled trials with regular physical exercise training, freely executed physical activity, or skeletal muscle stimulation protocols in GK rats published after 2008 were included. The results indicated that exercise reduces plasma insulin levels, increases skeletal muscle glycogen content, improves exercise tolerance, protects renal and myocardial function, and enhances blood oxygen flow in GK rats.

Comparison of affective responses during school physical education classes with different recovery times / Comparação das respostas afetivas durante aulas de educação física escolar com diferentes tempos de recuperação

ABSTRACT This study aimed to verify the effect of exercise recovery time on the affective responses during a circuit training in physical education classes. Forty-six apparently healthy young adolescents (twenty-one girls) (12.85 ± 0.94 years; 49.7 ± 8.93 kg; 1.59 ± 0.08 cm; 19.51 ± 3.28 kg/m2) participated in this study. Were submitted participants for two physical education classes, based on circuited model of the same intensity, but with different recovery times (2 min and 1 min). The study was carried out in two phases: baseline and intervention. Affect, Arousal, and Ratings of Perceived Exertion data were analyzed using paired t-tests, considering a significance level of p < 0.05. The class with longer rest time (2 min) provided greater affection (t(45) = 3.586; p < 0,001) and less perceived effort (t(45) = 2.295; p = 0,026). The intensity manipulation strategy was effective in providing different affective responses, in which classes perceived as more intense, resulting in the decline of affect.

RESUMO O objetivo do estudo foi verificar o efeito do tempo de recuperação do exercício nas respostas afetivas durante um treinamento em circuito nas aulas de educação física. Quarenta e seis jovens adolescentes aparentemente saudáveis (vinte e uma meninas), com (12.85 ± 0.94 anos; 49.7 ± 8.93 kg; 1.59 ± 0.08 cm; 19.51 ± 3.28 kg/m2), participaram do estudo. Os participantes foram submetidos a duas aulas de educação física escolar, baseados em modelo de circuitos de mesma intensidade, porém com tempos de recuperação diferentes (2 min e 1 min). O estudo foi realizado em duas fases: base e intervenção. Os dados de Afeto, Ativação e Percepção Subjetiva do Esforço, foram analisados através de testes t pareados, considerando um nível de significância de p < 0,05. A aula com maior tempo de descanso (2 min) proporcionou maior afeto (t(45) = 3.586; p < 0,001) e menor esforço percebido (t(45) = 2.295; p = 0,026). A estratégia de manipulação da intensidade foi efetiva para proporcionar respostas afetivas diferentes, em que a aula percebida como mais intensa resultou no declínio do afeto.

Effect of acute high-intensity exercise on appetite hormones in adults: A meta-analysis / 中国组织工程研究

OBJECTIVE: Acute high-intensity exercise can temporarily suppress appetite, but the effect of appetite hormones in this process is inconclusive. Meta-analysis is used to explore the effects of acute high-intensity exercise on adult appetite hormones, and provide theoretical basis for the follow-up research on the effects of exercise on appetite hormones. METHODS: Chinese and International databases such as CNKI, WanFang, Web of Science, PubMed and other databases were searched for articles regarding the effects of acute high-intensity exercise on appetite hormones. The literature search time span was from inception to August 17, 2019. The subjects included in the article were all adults. The intervention measure was a single high-intensity exercise. The outcome indicators were one or combination of acylated ghrelin, peptide YY, peptide YY 3-36, pancreatic polypeptide, and pancreatic height, and glucagon-like peptide-1 expressed by area under curves. In this meta-analysis, an improved version of Cochrane risk bias tool was used to evaluate methodological quality, and Revman 5.3 and STATA15.0 software were used for the meta-analysis of the outcome indicators of the included literature. RESULTS: A total of 18 research literatures were included, with a total of 212 subjects, including 179 males and 33 females. The literature quality evaluation results showed that the overall literature quality was high. Meta-analysis results showed that acute high-intensity exercise could significantly inhibit acylated ghrelin level (standardized mean difference (SMD)=-0.27, 95% confidence interval (CI):-0.45 to-0.08, P < 0.05), and significantly increase peptide YY (SMD=-0.31, 95%CI: 0.07-0.54, P < 0.05). Although there was an increase in the levels of peptide YY 3-36 (SMD=0.29, 95%CI:-0.19 to 0.77, P 0.05), pancreatic polypeptide (SMD=0.37, 95%CI:-0.07 to 0.81, P 0.05), and glucagon-like peptide-1 (SMD=0.29, 95%CI:-0.17 to 0.75, P 0.05) after acute highintensity exercise, it had no significant significance. CONCLUSION: Overall, acute high-intensity exercise has a certain effect on the level of appetite hormones, which can significantly inhibit orexigenic hormones and increase anorexigenic gastrointestinal hormones. The results suggest that acute high-intensity exercise can effectively regulate the secretion of appetite hormones, thereby controlling appetite and food intake, and can play a positive role in weight management. But future large-sample trials are needed.

Advance in Exercise Intensity of Rehabilitaion for Patients with Chronic Kidney Disease (review) / 中国康复理论与实践

Exercise training is applying in renal rehabilitation. Intensity is an important parameter of exercise prescription for patients with chronic kidney disease (CKD). Exercise intensity can be measured in both subjective and objective ways, the former such as Borg Score Scale and International Physical Activity Questionnaire, the latter such as peak oxygen uptake and lactic acid threshold, etc. The ways based on oxygen consumption are the most accurate, and the subjective measurement can be a supplement. The benefits of low-intensity exercise are unclear for CKD patients since insufficient researches; moderate-intensity exercise has been proved to be safe and beneficial; vigorous-intensity exercise may protect renal function of CKD, but the safety needs more studies.

Effects of exercise intensity on the stretch-shortening cycle function of the lower limbs after cycling / 体力科学

This study aimed to elucidate the effects of exercise intensity on stretch-shortening cycle (SSC) function of the lower limbs after cycling. Ten male triathletes performed a cycling graded test to determine the ventilatory threshold (VT) and two hopping-cycling (30 min of cycling at 90 or 110% VT)-hopping tests. The two hopping-cycling-hopping tests performed in random order. Power output (PO), heart rate (HR) and rate of perceived exertion (RPE) were monitored throughout the 30-min cycling. Blood lactate concentrations (BLa) were measured in order to assess metabolic stress. The SSC function was calculated as the ratio of the jump height to the time spent in contact with the ground (reactive strength index [RSI]). PO, HR and RPE values during cycling at 110%VT was higher than at 90%VT (p < 0.01). BLa value after the cycling at 110%VT was higher than at 90%VT (90%VT: 2.4±1.0 vs. 110%VT: 5.9±2.8 mmol/L, p < 0.01). Regardless of the cycling exercise intensity, the RSI significantly decreased after the cycling exercise (p < 0.01). The RSI remained decreased at 15 min after the cycling exercise (p < 0.05). These results demonstrated that the SSC function decreased after cycling. Exercise intensity during cycling is likely to have no effect on the decrease in SSC function.

Training variables and autonomic nervous system adaption / 中国组织工程研究

BACKGROUND: Autonomic nervous system plays a critical role in mediating cardiovascular system to adapt the metabolic demands of the muscle activity, and is an important presenter and supporter of physical activity. OBJECTIVE: To systematically analyze the possible effects of exercise intensity, exercise modality, and exercise duration on autonomic nervous system regulation during and after exercise through reviewing the related literature on the autonomic nervous system and heart rate variability assessment of autonomic nervous system, so as to understand the mechanisms that meet the metabolic needs of physical activities. METHODS: PubMed and CNKI databases were searched using the keywords of “autonomic nerves system, heart rate variability, exercise intensity, exercise modality, exercise duration” in English and Chinese, respectively. The studies published from 1999 to 2018 were retrieved. RESULTS AND CONCLUSION: Cardiac autonomic neuromodulation is evaluated by heart rate variability index based on RR interval changes. Heart rate variability is a sensitive marker that reflects the co-regulation of cardiac function in sympathetic nerves and parasympathetic (vagal) nerves in the autonomic nervous system. In addition, the heart rate variability signals contain a large amount of regulatory information, including cardiovascular system, hormones and body fluids. Therefore, the mechanism of exercise-induced cardiac autonomic nervous system adaptation is still unclear. Exercise intensity may be the main factor affecting the regulation of cardiac autonomic nervous system during and after exercise. The training parameters such as exercise form and duration, as well as their interaction effects, may affect the adaptive process of cardiac autonomic nervous system.

Effects of different intensities of exercises on BNIP3-mediated mitophagy in skeletal muscle / 中国组织工程研究

BACKGROUND: Different intensities of exercises make different effects on human body, and the changes of skeletal muscle after exercise remain unclear. Physical change of human body during exercise Is a hotspot. OBJECTIVE: To Investigate the effect of different Intensities of exercises on the mass of rat skeletal muscle, and the role of BNIP3-mediated mitophagy In maintaining skeletal muscle mass. METHODS: The study was approved by the Laboratory Animal Ethical Committee of Beijing Sport University. Twenty-four healthy male Sprague-Dawley rats aged 8 weeks were randomly divided Into three groups: Control, moderate-intenslty exercise (5°, 15 m/min, 1 hour, 60% VOanux) and hlgh-lntenslty exercise (5°, 35 m/min, 20 minutes, 85% V02max) groups (n=8/group), 6 times weekly. The rat soleus and gastrocnemius were removed to measure the wet weights. The cross-sectional area of muscle fiber was detected by immunofluorescence. The protein expression levels of BNIP3, p62 and LC3 in the soleus and gastrocnemius were detected by western blot assay. RESULTS AND CONCLUSION: (1) The wet weight of gastrocnemius in the exercise groups was significantly lower than that in the control group (P < 0.01). (2) The cross-sectional area of gastrocnemius fiber in the exercise groups was significantly less than that in the control group (P < 0.01), and the cross-sectional area of soleus fiber in the exercise groups was significantly more than that in the control group (P < 0.01). (3) The moderate-intensity exercise induced increased mitophagy, and the expression level of BNIP3 and LC3-II/LC3-I were up-regulated (P < 0.05), while p62 was down-regulated (P < 0.05) compared with the control group. The expression level of LC3-II/LC3-I in the high-intensity exercise group was higher (P < 0.05), but the expression level of p62 was lower than that in the moderate-intensity exercise group and the expression of BNIP3 was decreased (P < 0.05). (4) To conclude, 4-week moderate-intensity exercise can promote the removal of damaged mitochondria and maintain skeletal muscle function by increasing BNIP3-regulated mitophagy in skeletal muscle. In high-intensity exercise, the level of autophagy is higher, but will cause harmful effect on skeletal muscle.

Synergistic effects of brain-derived neurotrophic factor (BDNF) and exercise intensity on memory in the adolescent brain: a commentary

This commentary highlights the recently published study by Jeon and Ha (Environ Health Prev Med 22:27, 2017) examining the effects of exercise intensity and brain-derived neurotrophic factor (BDNF) on memory in adolescents. This 12-week training study elicited increases in BDNF and improvements in working memory during moderate- and high-intensity exercise, which may have been achieved through improved brain tissue oxygenation, nutrient delivery, and BDNF mRNA expression. These improvements highlight the positive neuroendocrinological effects of BDNF and its role as a potential candidate molecule, as a mediator of synaptic plasticity. In this commentary, we aim to highlight the strengths and potential areas of consideration of Jeon and Ha (Environ Health Prev Med 22:27, 2017). We also offer insight into the clinical implications of this study, such as advocating for exercise in healthy children and as adjunctive therapy in pathological states. This study is promising and further highlights the importance of cardiorespiratory exercise in improving physiological health and cognitive functioning in youth through the phenomenon of neuroplasticity.

Match internal load in youth elite soccer players is period, playing position and intermittent running capacity dependent

The aims of this study were: i) to verify whether player internal load (PIL) monitored via heart rate (HR) varies with game-time and playing position; ii) whether intermittent running capacity (IRC) is related to the maintenance of within-match PIL in elite youth (U-15) soccer players. Method: Twenty-one elite soccer players (14±0.5 yrs, 172±7 cm, 63±6 kg) had their heart rate monitored (beats/min) in five matches and were tested twice for IRC (Yo-YoIR2, distance [m]) over a seven-week competitive season. Percentage of maximal heart rate (%HRmax) and time spent (TS%) in five zones (Z1[<70%]; Z2[71-85%]; Z3[86-90%]; Z4[91-95%] and Z5[>96%]) were our PIL indexes. Data from three complete games in the same position of each player were analyzed and matches halves, time intervals (T1 to T6), and playing positions (fullbacks, central defenders and forwards [N=5 each], midfielders [N=6]) were compared, and the relationship between IRC and within-match PIL was determined. Results: PIL was higher in 1st (86±3%) than in the 2nd half (84±4%; p<.001). The 2nd half had more TS% in Z1 and Z2 (p<.05). PIL in T4 was the lowest (p<.01), and in T6, it was lower than T1 and T2 (p<.01). Fullbacks and midfielders showed higher PIL and higher TS% in Z4 (p<.05) than the other positional roles. The average IRC correlated with PIL in T6 (r=.56, p<.01) only. Conclusion: In conclusion, the internal load in elite youth (U-15) soccer players varies with game-time and playing position; and their IRC is related to the maintenance of within-match PIL.(AU)

Inflammation and oxidative stress in heart failure: effects of exercise intensity and duration

Although acute exercise is apparently pro-inflammatory and increases oxidative stress, it can promote the necessary stress stimulus to train chronic adaptations in patients with chronic heart failure (CHF). This study aimed to compare the effects of exercise intensity and duration on the inflammatory markers soluble tumor necrosis factor receptor (sTNFR1) and interleukin-6 (IL-6), and on oxidative stress [malondialdehyde (MDA) and antioxidant enzymes: catalase (CAT) and superoxide dismutase (SOD)] in individuals with CHF. Eighteen patients performed three exercise sessions: 30 min of moderate-intensity (M30) exercise, 30 min of low-intensity (L30) exercise, and 45 min of low-intensity (L45) exercise. Blood analysis was performed before exercise (baseline), immediately after each session (after), and 1 h after the end of each session (1h after). Thirty min of M30 exercise promoted a larger stressor stimulus, both pro-inflammatory and pro-oxidative, than that promoted by exercises L30 and L45. This was evidenced by increased sTNFR1 and MDA levels after exercise M30. In response to this stressor stimulus, 1 h after exercise, there was an increase in IL-6 and CAT levels, and a return of sTNFR1 to baseline levels. These findings suggest that compared with the duration of exercise, the exercise intensity was an important factor of physiologic adjustments.

Characteristics of pulmonary ventilation volumes under different exercise intensity with time / 军事医学

Objective To observe the changes of the pulmonary ventilation(VE)volume under different exercise intensities along with time,and to explore the best time for measuring VE under different intensities of exercise.Methods Sixty-one young mals were selected as subjects,who engaged in exercise of different intensities on the cycle ergometer(20, 40, 60, 80, 100, 120, 140, 160, and 180 W).The duration of exercise of each intensity was 6 minutes,the cardiopulmonary function was detected using a portable instrument,and real time monitoring of VE changes was enforced. Results (1)For exercise of intensity 20 W, VE initially increased fast with time, but after 1 min,it ceased to rise and remained stable.There was no significant difference at 1 min and afterwards(P>0.05).(2)The case was the same with exercise of the intensity 40 and 60 W.(3)For intensities of 80,100,120,140,and 160 W,VE became stable at 3 min. (4)For exercise of intensity 180 W,VE became stable at 4 min.Conclusion The time taken for VE to achieve stability under different intensities is different,which is positively correlated with the intensity of exercise.The greater the intensity of exercise,the longer it takes to achieve stability.

A Comparative Study on Effects of Exercise Intensity and Duration on Left and Right Ventricular / 中国运动医学杂志

Objective To examine the effects of exercise intensity and duration on the structure,function and fibrosis of the left and right ventricular,and to discuss the potential mechanism in these processes.Methods Forty-eight male Sprague-Dawley rats were randomly divided into a sedentary(Sed)group,a moderate exercise(ME)group and an intensive exercise(IE) group,each of 16.Rats in Sed group were not given any training,while those in ME group and IE group run on treadmill at the speed of 15.2 m/min with the slope gradient of 5° and 28 m/min with the slope gradient of 10 degree 1 hour per day,5 days per week.Eight and 16 weeks after the training,we recorded the body weight and measure end-diastolic diameter,end-diastolic wall thickness,and ejection fraction of both ventriculars using the ultrasonic testing.All rats were then sacrificed after blood sampling.Elisa was used to measure serum cTnI concentration,and sirius red staining was applied to evaluate collagen volume fraction of both ventriculars.Results Eight or sixteen weeks after the training,the average bi-ventricular end-diastolic diameter of ME and IE rats was bigger than Sed group.There were no differences in end-diastolic diameter of both ventricular between ME group and IE group after sixteen-week training,but the left ventricular end-diastolic diameter of IE group was greater than ME group.As exercise intensive increased and time accumulated,the end-diastolic wall thickness of both ventriculars increased but without statistical significance.At sixteen-week intervention,the bi-ventricular ejection fraction of IE rats was significantly lower than Sed and ME groups,while there was a decreasing trend eight weeks earlier without significant differences.After 8 or 16 weeks of training,the serum cTnI was significantly higher in IE rats than Sed group or ME group,but there was no significant differences between ME group and Sed group.After 16 weeks' exercises,the average bi-ventricular collagen volume fraction of ME or IE group was greater than that after 8 weeks' exercises.The average collagen volume fraction of the right ventricular was greater than Sed group at the same time points,and after sixteenweek training the right ventricular collagen volume fraction in IE group was significantly greater than ME group.However,there were no significant differences in the measurement of the left side among different groups.The serum cTnI was negatively correlated with the left and right ventricular systolic function(r=-0.327,P=0.029 and r=-0.582,P=0.000).Moreover,it was positively correlated with the right ventricular collagen volume fraction moderately,but had no correlation with the left ventricular collagen volume fraction.Conclusion(1)Sixteen-week moderate and intensive exercise result in left ventricular dilation,and the dilation increases with the increase of the exercise intensity.Only 8 weeks' exercise at the same intensity can lead to right ventricular dilation,but exercise intensity has little influence on the right ventricular dilation.(2)Long-term moderate or intensive endurance exercises may cause bi-ventricular hypertrophy potentially.The left ventricular hypertrophy and dilation may not be synchronous with hypertrophy followed by dilation,while the right ventricular hypertrophy and dilation is synchronous.(3)The temporary decrease in bi-ventricular systolic function after intensive endurance exercise may be caused by ventricular injury,with more serious injury in the right ventricular than in the left.Moderate exercises don't cause ventricular injury,thus there is little or no influence on ejection fraction.(4) Long-term (8 or 16 weeks)moderate or intensive endurance exercises can increase the right ventricular collagen volume fraction,which may indicate cardiac fibrosis following right ventricular injury but not in the left ventricular.The bi-ventricular collagen volume fraction at sixteenth week in ME and IE rats are greater than corresponding rats at eighth week.It may result from the hypertrophy of bi-ventricular cardiomyocyte after 8-week training,followed by increase in the extracellular matrix but not cardiac fibrosis.

Needs satisfaction ffect on exercise emotional response: a serial mediation analysis with motivational regulations and exercise intensity

Abstract Regarding psychological responses to exercise, this study aimed to analyze the mediating effects of motivational regulations and intensity in the association between basic psychological needs satisfaction and emotional responses. This was a cross-sectional study of 495 health club members (M = 40.50 years; SD = 13.54); of these, 186 were women (37.6%) and 309 men (62.4%), with an average attendance of 2.61 sessions per week (SD=1.29). Self-determination theory motivational regulations and basic psychological needs (BPN), perceived exercise intensity, and emotional response were measured. Serial mediation procedures were followed to test the interactions of variables. Models with autonomous regulations predicted positive emotional responses. As for the negative emotional response, the models with external regulation presented the highest predictions for negative activation. Results indicate that BPN satisfaction is associated with better emotional response, partially explained by autonomous regulations and perceived exercise intensity. In externally regulated individuals, perceived exercise intensity appears to be important to sustain a better emotional response.

Agreement analysis between critical power and intensity corresponding to 50% ∆ in cycling exercise / Análise de concordância entre a potência crítica e a intensidade correspondente ao 50% ∆ no exercício de ciclismo

Abstract The purpose of this study was to determine the level of agreement between critical power (CP) and intensity corresponding to 50% of the difference (50% ∆) between oxygen uptake (VO2) at lactate threshold (LT) and maximal oxygen uptake (VO2max) in untrained subjects during cycling exercise. Fifteen healthy male subjects (age: 26.0 ± 3.5 years; body weight: 76.6 ± 10.4 kg; height: 178.2 ± 7.6 cm) volunteered to participate in the study. Each subject performed a series of tests to determine LT, VO2LT, CP, VO2CP, 50% ∆, VO250% ∆, and VO2max. The values LT, CP, VO2CP, 50% ∆, VO250% ∆ and VO2max were 109 ± 15 W, 1.84 ± 0.23 L.min-1, 207 ± 17 W, 2.78 ± 0.27 L.min-1, 206 ± 19 W, 2.77 ± 0.29 L.min-1, and 3.71 ± 0.49 L.min-1, respectively. No signficant difference was found between CP and 50% ∆ (t = 0.16; p = 0.87) or between VO2CP and VO250% ∆ (t = 0.12; p = 0.90). However, the bias ± 95% limits of agreement for comparison between CP and 50% ∆ and between VO2CP and VO250% ∆ were 1 ± 27 W (0.3 ± 14.1%) and 0.01 ± 0.24 L.min-1 (0.2 ± 8.9%), respectively. In summary, the mean CP and 50% ∆ values were not significantly different. However, considering the limits of agreement between the two intensities, CP estimated based on 50% ∆ might result in a remarkable error when the absolute variability of individual differences is taken into account.

Resumo A proposta deste estudo foi determinar o nível de concordância entre a potência crítica (PC) e a intensidade correspondente a 50% da diferença (50% ∆) entre o consumo de oxigênio (VO2) no limiar de lactato (LL) e o consumo máximo de oxigênio (VO2max) em sujeitos não treinados durante o exercício de ciclismo. Quinze sujeitos saudáveis do sexo masculino (idade: 26,0 ± 3,5 anos; massa corporal: 76,6 ± 10,4 kg; estatura: 178,2 ± 7,6 cm) participaram deste estudo. Cada sujeito realizou uma série de testes para determinar o LL, VO2.LL, PC, VO2.PC, 50% ∆, VO250% ∆ e VO2max. Os valores de LL, VO2LL, PC, VO2PC, 50% ∆, VO250% ∆ e VO2max foram 109 ± 15 W, 1,84 ± 0,23 L.min-1, 207 ± 17 W, 2,78 ± 0,27 L.min-1, 206 ± 19 W, 2,77 ± 0,29 L.min-1 e 3,71 ± 0,49 L.min-1, respectivamente. Nenhuma diferença significavita foi encontrada entre a PC e o 50% ∆ (t = 0.16; p = 0.87) e entre o VO2PC e o VO250% ∆ (t = 0.12; p = 0.90). Entretanto, o bias ± 95% dos limites de concordância para as comparações entre a PC e o 50% ∆ e entre o VO2PC e o VO250% ∆ foram 1 ± 27 W (0,3 ± 14,1%) e 0,01 ± 0,24 L.min-1 (0,2 ± 8,9%), respectivamente. Em resumo, os valores médios de PC e 50% ∆ não foram significativamente diferentes. No entanto, a PC estimada pelo 50% ∆ pode resultas em um erro significativo quando a cariabilidade individual absoluta é considerada.

Analysis and comparison of intensity in specific soccer training sessions

This study compared the exercise intensity of four specific soccer training sessions (friendly and training match, tactical and technical workouts). Ten professional soccer players (24.2 ± 3.7 years, 177.9 ± 7.3 cm, 63.2 ± 4.6 mLO2•kg-1•min-l) were recruited. A treadmill progressive interval test was performed to determine the players' VO2max, maximal heart rate (HRmax), HR-VO2 curve, and the heart rate corresponding to blood lactate concentrations of 2 and 4 mmol/L. The heart rate during the training sessions was used to estimate the exercise intensity and to classify them into intensity zones (low-intensity: <2 mmol/L; moderate-intensity: between 2 and 4 mmol/L; high-intensity: >4 mmol/L). Exercise intensities were different among training sessions (friendly match: 86.0 ± 5.1% HRmax; training match: 81.2 ± 4.1% HRmax; tactical workout: 70.4 ± 5.3% HRmax; technical workout: 62.1 ± 3.6% HRmax). The friendly match presented the highest percentage of time performed in the high-intensity zone.

Este estudo comparou a intensidade de quatro treinamentos específicos de futebol (jogo treino, amistoso, treinos técnicos e táticos). Dez jogadores de futebol profissional foram recrutados (24,2 ± 3,7 anos, 177,9 ± 7,3 cm, 63,2 ± 4,6 mLO2•kg-1•min-l). Um teste progressivo intervalado em esteira foi realizado para determinar o VO2max, frequência cardíaca máxima (FCmax), curva FC-VO2, e frequência cardíaca correspondente às concentrações de lactato de 2 e 4 mmol/L. A frequência cardíaca dos treinos foi usada para estimar a intensidade do exercício e classificá-los em zonas de intensidade (baixa, <2 mmol/L; moderada: entre 2 e 4 mmol/L; alta: >4 mmol/L). As intensidades das sessões de treinamento foram diferentes (jogo amistoso: 86,0 ± 5,1% FCmax; jogo treino: 81,2 ± 4,1 % FCmax; treino tático: 70,4 ± 5,3% FCmax; treino técnico: 62,1 ± 3,6% FCmax). O jogo amistoso apresentou porcentagem mais alta de tempo realizado na zona de intensidade alta.

Este estudio comparó la intensidad de cuatro entrenamientos específicos de futbol (juego de entrenamiento, amistoso, técnico y táctico). Diez jugadores de futbol profesional fueron reclutados (24,2 ± 3,7 años, 177,9 ± 7,3 cm, 63,2 ± 4,6 mLO2•kg-1•min-l). Un examen con intervalos progresivos en la caminadora fue realizado para determinar: VO2max, FCmax, curva FC-VO2 y frecuencia cardiaca correspondiente a las concentraciones de lactato de 2 y 4 mml/L. La frecuencia cardiaca de los entrenamientos fue usada para estimar la intensidad del ejercicio y clasificar zonas de intensidad (baja <2 mmol/L; moderada >2 y <4 mmol/L; alta >4 mmol/L). Las intensidades de las sesiones de entrenamiento fueron diferentes (juego amistoso: 86,0 ± 5,1% FCmax; entrenamiento 81,2 ± 4,1 % FCmax; entrenamiento táctico 70,4 ± 5,3% FCmax; entrenamiento técnico 62,1 ± 3,6% FCmax). El juego amistoso presentó porcentaje más alto de tiempo realizado en la zona de intensidad alta.

Insuficiência cardíaca, exercício físico e sistema inflamatório / Heart failure, exercise training and systemic inflammatory

Fundamentação: No contexto do tratamento da insuficiência cardíaca (IC) se torna relevante a melhor compreensão das repercussões da interação entre exercício físico e inflamação, tendo em vista a forte influência de ambos na evolução clínica dos portadores da síndrome. Objetivo: Busca de informações sobre as repercussões do exercício físico no perfil inflamatório de pacientes com IC. Métodos: Busca por periódicos nas bases de dados, CONCHRANE, PUBMED, LILACS. Os seguintes termos MeSH foram utilizados: heart failure, inflammatory mediators e exercise. Os estudos foram selecionados por dois avaliadores, segundo critérios do instrumento Delphi List. Resultados: Dezenove ensaios clínicos controlados foram selecionados. Os estudos foram semelhantes quanto à modalidade e protocolos de exercícios físicos utilizados na investigação dos efeitos no comportamento dos mediadores inflamatórios, havendo, entretanto, predominância no uso da atividade aeróbica de moderada intensidade. Os desfechos dos estudos mostram redução crônica de citocinas pró-inflamatória de ação sistêmica e cardíaca, como também de ação endotelial e de apoptose celular em decorrência do exercício físico. Nenhum estudo avaliou a influência do exercício de alta intensidade sobre os marcadores inflamatórios. Conclusões: Tem sido demonstrado que o exercício físico utilizado predominantemente de forma aeróbica com intensidade moderada proporciona estabilização e diminuição dos marcadores pró-inflamatórios, algo desejável no tratamento da IC. Não foram encontrados estudos evidenciando o efeito isolado do exercício resistido, assim como o efeito do exercício de alta intensidade sobre os marcadores inflamatórios em pacientes com insuficiência cardíaca.

Effect of prior exercise intensity on physiological response and short-term aerobic performance / Efeito da intensidade do exercício prévio na resposta fisiológica e na performance aeróbia de curta duração

Athletes of different sports have frequently used warm-up exercises as preparation for the training session or competition. Increased metabolism and performance, as well as musculoskeletal injury prevention, are among the reasons that lead coaches to adopt this procedure. The effects of prior exercise have been studied to analyze the limiting factors of physiological adjustments at the beginning of exercise and its effects on subsequent exercise performance. Thus, this article analyzes studies that have investigated the effects of prior exercise on the cardiorespiratory and metabolic responses and short-term aerobic performance. In this context, factors such as prior exercise intensity and duration and recovery period between exercise sessions are discussed, and the possible mechanisms that could explain the effects of prior exercise are presented. The effects of prior exercise on the oxygen uptake (VO2) kinetics do not seem to depend on the prior exercise intensity and recovery period between exercise sessions (i.e., prior and subsequent). However, the effects on exercise tolerance appear to depend on the interaction between the intensity of both exercises and the recovery period between them.

Atletas de diferentes esportes têm usado frequentemente exercícios de aquecimento como forma de preparação para a sessão de treinamento ou a competição. Entre as razões que levam os técnicos a adotarem este procedimento estão o aumento no metabolismo e na performance, como também a prevenção de lesões musculoesqueléticas. Os efeitos do exercício prévio têm sido estudados para se analisar os fatores limitantes dos ajustes fisiológicos no início do exercício e seu efeito na performance do exercício subsequente. Assim, este artigo analisa estudos que investigaram os efeitos do exercício prévio nas respostas cardiorrespiratórias, metabólicas e na performance aeróbia de curta duração. Neste contexto, fatores como a intensidade e a duração do exercício prévio e o período de recuperação entre as sessões de exercício prévio e do exercício subsequente são discutidos. São apresentados também os possíveis mecanismos que poderiam explicar os efeitos do exercício prévio nas respostas fisiológicas e na performance. Os efeitos do exercício prévio na cinética do consumo de oxigênio (VO2) não parecem depender da intensidade do exercício prévio e do período de recuperação entre as sessões de exercício (i.e., prévio e subsequente). Porém, os efeitos na tolerância ao exercício parecem depender da interação entre a intensidade dos dois exercícios e do período de recuperação entre eles.

Exercise Strategies for the Prevention and Treatment of Non-alcoholic Fatty Liver Disease

The prevalence of non-alcoholic fatty liver disease (NAFLD) is steadily increasing in conjunction with increases in obesity, type 2 diabetes, and physical inactivity. NAFLD encompasses a spectrum of conditions associated with lipid deposition in hepatocytes, ranging from simple steatosis to non-alcoholic steatohepatitis (NASH) and to advanced fibrosis and cirrhosis. A large proportion of patients with NAFLD have co-existing metabolic syndrome, which is also a major risk factor of cardiovascular disease. There is an urgency to recognize that NAFLD poses an additional risk for cardiovascular disease and should involve early aggressive risk factor modification. A lifestyle modification of diet and physical activity targeting substantial weight loss is considered as the first-line defense system against NAFLD. In this review, the roles of physical activity are discussed as an effective and safe means to combat NAFLD and its metabolic complications.