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1.
Motriz (Online) ; 28: e10220005522, 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1406006

ABSTRACT

Abstract Aim: We investigated the effects of continuous or interval aerobic exercise training on vascular reactivity of female rats fed with fructose. Methods: Female Wistar rats (8-wk old) were divided into: sedentary (SD), continuous training (CTR), and interval training (ITR). Moderate intensity training protocols consisted of running 3 days/week for 7 weeks. CTR ran 40 min at 30%-40% of the maximal speed (MS) and TRI consisted of 7 sets of 1 min at 70% of MS followed by 3 min at 35% of MS. Animals were fed with standard chow and fructose (10%) in drinking water. Concentration-response curves to acetylcholine and phenylephrine, and oxidative stress biomarkers, were determined in the aorta. Body weight gain, visceral fat, and plasma triglycerides and glucose were also evaluated. Results: Endothelium-dependent relaxation was significantly increased by both exercise regimens (CTR: Emax = 85 ± 6% and ITR: Emax = 84 ± 1%) compared to sedentary rats (SD: Emax = 62 ± 5%). The contractile maximal response was not different but phenylephrine potency was increased in CTR (pEC50: 8.41 ± 0.19) and reduced in ITR (pEC50: 7.06 ± 0.11) compared to SD (pEC50: 7.77 ± 0.08). In addition, the generation of superoxide was lower in trained groups as compared with sedentary (about −28% in CTR and −22% in ITR). TBARS and nitrate/nitrite levels were not modified. Compared to the SD group, ITR gained 39% less body weight and CTR has 29% less visceral fat. Glucose and triglycerides were not modified. Conclusion: CTR and ITR, carried out 3 days/week, were efficient to improve endothelium-dependent relaxation and reduce superoxide generation in the aorta from female rats fed with fructose.

2.
Chinese Journal of Biochemistry and Molecular Biology ; (12): 1547-1554, 2022.
Article in Chinese | WPRIM | ID: wpr-1015835

ABSTRACT

As one of the causes of exercise-induced fatigue, exercise-induced metabolic acidosis has attracted much attention. The effect of pyruvate supplementation on exercise-induced metabolic acidosis is rarely reported, and its mechanism has not been fully elucidated. Monocarboxylate transporters (MCTs) play an important role in the maintenance of the acid-base balance, but it is not clear whether pyruvate can alleviate acidosis by increasing the expression of MCTs. In this study, pyruvate (616 mg/kg/day) was supplemented to rats for one week, and then acute HIIE was performed. The HIIE protocol comprised 13 repeats of a 60 s sprint session at 110% VO

3.
Chinese Journal of Applied Physiology ; (6): 47-52, 2022.
Article in Chinese | WPRIM | ID: wpr-927896

ABSTRACT

Objective: To investigate the effects of continuous exercise training (CT) and high-intensity interval exercise training (HIIT) on liver lipid metabolism and the correlation of the level of fibroblast growth factor 21(FGF21) in serum and liver tissues. Methods: Male SD rats were randomly divided into normal diet group (N) and obesity model group (H) after 1 week of adaptive feeding. Rats in the obesity model group were fed with 45% high-fat diet for about 8 weeks, and 20% weight increase compared with normal rats was considered as obesity. The rats were divided into normal diet control group (LC), normal diet HIIT group (LHI), normal diet CT group (LCT), High fat diet-induced obese control group (OC), obese HIIT group (OHI), and obese CT group (OCT) (n=10). Exercised rats were given weight-bearing swimming training intervention for 8 weeks. Blood samples were collected at least 24h after the last exercise intervention to detect the serum levels of inflammatory factors and FGF21. Liver tissue samples were collected to detect the lipid content, lipid metabolic enzyme content and FGF21 expression level. Results: Compared with LC group, the body weight, serum inflammatory factors levels and hepatic triglyceride content were increased significantly (P<0.05). Hepatic triglyceride content was downregulated in LHI group and FGF21 expression level was enhanced in LCT group (P<0.05). Compared with OC group, the body weight and hepatic triglyceride content were decreased significantly (P<0.05), mitochondrial CPT-1β and β-HAD enzyme contents in liver were increased significantly (P<0.05) in OHI group, the contents of LPL and FAT/CD36 enzyme in liver and the levels of FGF21 in serum and liver of OCT group were increased significantly (P<0.05). Conclusion: Both exercise modes can reduce the body weight in normal and obese rats, and lipid deposition in the liver of obese rats. HIIT has a more significant effect on alleviating liver lipid deposition in obese rats by upregulating mitochondrial lipid oxidation level in normal and obese rats. CT improves the levels of FGF21 in serum and liver tissues of normal and obese rats, enhances enzyme contents that involved in fatty acids uptake to the liver, which has limited effect on alleviating lipid deposition in liver of obese rats.


Subject(s)
Animals , Male , Rats , Body Weight , Diet, High-Fat/adverse effects , Fatty Liver , Fibroblast Growth Factors , Obesity/metabolism , Rats, Sprague-Dawley , Triglycerides
4.
Rev. Pesqui. Fisioter ; 11(1): 211-217, Fev. 2021. ilus, tab
Article in English, Portuguese | LILACS | ID: biblio-1253387

ABSTRACT

INTRODUÇÃO: O uso de contraceptivos orais combinados (COC) trata-se de um fator de risco para a doença aterosclerótica por comprometer o perfil lipídico e inflamatório, podendo o exercício físico minimizar essas condições. OBJETIVO: Testar a hipótese de que exercício físico pode modificar o perfil lipídico e inflamatório de mulheres em uso COC. MÉTODOS: Protocolo de um estudo sequencial cruzado com mulheres de 20 e 30 anos, irregularmente ativas, em uso de COC há pelo menos 6 meses. Realizouse uma avaliação físico-clínica (AFC) nas participantes com medidas antropométricas, VO2máx. indireto e análise do perfil lipídico e inflamatório. Na sequência separou-se as participantes em 2 grupos: O grupo intervenção inicial (GII) que iniciou praticando exercícios intervalados de alta intensidade por 2 meses, e o grupo intervenção posterior (GIP), que seguiu irregularmente ativo pelo mesmo período. Em seguida o GII e o GIP alternariam suas condições por mais 2 meses, totalizando 4 meses de acompanhamento e 3 AFC, realizadas no início, após 2 meses e ao final do estudo. As informações colhidas foram divididas em 3 momentos: Momento inicial (MI), momento pós exercício (MPE) e pós inatividade (MPI).


INTRODUCTION: The use of combined oral contraceptives (COC) is a risk factor for atherosclerotic disease because it compromises the lipid and inflammatory profile, and physical exercise can minimize these conditions. OBJECTIVE: To test the hypothesis that high intensity interval physical exercise promotes changes in the lipid and inflammatory profile of women who are irregularly active using COC. METHODS: Protocol of a crosssectional study with women of 20 and 30 years, irregularly active, using COC for at least 6 months. A physicalclinical assessment (AFC) was performed on the participants with anthropometric measurements, VO2max. analysis and analysis of the lipid and inflammatory profile. Afterwards, the participants were divided into 2 groups: the initial intervention group (GII) that started practicing high intensity interval exercises for 2 months, and the posterior intervention group (GIP), which remained irregularly active for the same period. Then the GII and GIP would alternate their conditions for another 2 months, totaling 4 months of follow-up and 3 AFC, performed at the beginning, after 2 months and at the end of the study. The information collected was divided into 3 moments: Initial moment (MI), post-exercise moment (MPE) and post-inactivity (MPI).


Subject(s)
Contraceptives, Oral, Hormonal , Women , Risk Factors
5.
Int. j. cardiovasc. sci. (Impr.) ; 32(1): 48-54, jan.-fev. 2019. tab
Article in English | LILACS | ID: biblio-981576

ABSTRACT

Background: Systemic arterial hypertension (SAH) is one of the main risk factors for heart disease. Among the benefits linked to different modalities of physical exercise, post-exercise hypotension (PEH) is a key point for exercise prescription in this condition. Objective: To investigate and compare PEH in response to continuous aerobic exercise (CONT) and high-intensity interval exercise (HIIE), matched by volume, in sedentary individuals. Methods: A randomized cross-over study, composed of sedentary, healthy male subjects submitted to two acute physical exercise protocols matched by volume, HIIE and CONT, on a treadmill. Hemodynamic measures for the evaluation of PEH were performed pre, immediately after exercise and every five minutes thereafter, during one hour of recovery. Two-way ANOVA with repeated measurements was used for comparisons between groups and Bonferroni post hoc test as appropriate. P < 0.05 was considered significant. Results: Both exercise protocols promoted significant PEH, with reductions in systolic blood pressure (SBP) and mean arterial pressure (MAP). HIIE promoted a reduction of SBP and MAP at the 15th minute, whereas the same effect was observed at the 30th following CONT. Conclusion: Both HIIE and CONT, matched by volume, promote PEH of similar magnitude. However, PEH occurs earlier following HIIE, suggesting a better time /effectiveness ratio, and an additional beneficial effect of this modality


Subject(s)
Humans , Male , Female , Exercise , Sedentary Behavior , Hypertension/physiopathology , Hypotension , Research Design , Blood Pressure , Body Mass Index , Data Interpretation, Statistical , Risk Factors , Analysis of Variance , Cardiomegaly , Guideline Adherence/standards , Exercise Test , Heart Rate
6.
Rev. bras. ciênc. mov ; 25(2): 52-61, abr.-jun. 2017. tab
Article in Portuguese | LILACS | ID: biblio-882108

ABSTRACT

O objetivo do trabalho foi comparar a resposta aguda das variáveis aeróbias durante o exercício intervalado de alta intensidade (EIAI) e o exercício contínuo moderado (ECONT) realizado por jovens com excesso de peso. Participaram do estudo 12 jovens (11,01 ± 1,82 anos; 69,09 ± 22,50kg; 154,43 ± 15,17; 28,27 ± 4,82kg/m2 ). Na primeira visita foi realizado um teste incremental máximo em cicloergômetro para determinação do consumo de oxigênio pico (VO2pico), potência pico e da frequência cardíaca pico (FCpico).Na segunda e terceira visitas foram realizados os protocolos de EIAI (10 repetições de 60s a 90% da potência pico para 60s de intervalo passivo) e ECONT (18 minutos contínuos a 50% da potência pico), ambos equalizados pelo trabalho total (kJ). Durante o EIAI e o ECONT, a FC e o consumo de oxigênio (VO2) foram continuamente mensurados. A concentração de lactato sanguíneo ([La]) foi determinada imediatamente após o término dos protocolos de exercício. Apesar da equalização do trabalho, os valores de FCpico (182 ± 3,34 vs 164 ± 3,34bpm), percentual do VO2pico (91 ± 2,00 vs. 76 ± 2,00 %), potência pico (105,0 ± 2,86 vs. 58,33 ± 2,86 W) e [La] (3,2 ± 0,12 vs. 1,8 ± 0,12 mmol.L-1 ) foram significantemente maiores no EIAI quando comparados ao ECONT. Concluímos que o EIAI resultou em maior estresse cardiovascular e metabólico comparado ao ECONT, refletido pelos valores de %VO2pico, FC e [La]. Por fim, destacamos a possibilidade do EIAI ser incorporado aos exercícios aeróbios de natureza contínua durante diferentes programas de atividade física praticada pelos jovens....(AU)


The aim of this study was to compare the acute response of aerobic variables during high intensity interval exercise (HIIE) and moderate continuous exercise (MCE) performed by obese adolescents. The study included 12 young (11.01 ± 1.82 years; 69.09 ± 22,50 kg; 154.43 ± 15.17cm; 28.27 ± 4.82 kg/m2 ). At the first visit was done a maximum incremental test on a cycle ergometer to determine the peak power and peak heart rate (HRpeak). At the second and third visits were conducted the EIAI (10 repetitions of 60s to 90% of peak power to 60s passive interval) and ECONT protocols (18 minutes continuously at 50% of peak power), both equalized by work (kJ). During HIIE and MCE, HR and oxygen consumption (VO2) were continuously measured. The blood lactate concentration ([La]) was determined immediately after the end of exercise protocols. Despite the equalization of work, HRpeak values (182 ± 3.34 vs 164 ± 3.34 bpm), percentage of VO2 peak (91 ± 2.00 vs. 2.00 ± 76%), power peak (105.0 ± 2.86 vs. 58.33 ± 2.86 W) and [La] (3.2 ± 1.8 vs. 0.12 ± 0.12 mmol.L-1 ) were significantly higher in HIIE compared to MCE. Concluded that HIIE results in an increase in cardiovascular and metabolic stress when VO2 peak, HR and [La]. Finally, we highlight the possibility to incorporate the HIIE in aerobic exercise continuous during different physical activity programs practiced by obese adolescents....(AU)


Subject(s)
Humans , Male , Female , Adolescent , Heart Rate , High-Intensity Interval Training , Obesity , Physical Fitness , Physical Education and Training
7.
Journal of Preventive Medicine ; (12): 550-554, 2017.
Article in Chinese | WPRIM | ID: wpr-792625

ABSTRACT

Objective To investigate the influence of high intensity interval exercise (HIIT) on peroxidation and vascular endothelial function for experimental hyperhomocysteinemia (HHcy) rats. Methods Thirty five male rats were randomly divided into 4 groups. Control group (n=8) was given ordinary feed. High methionine group (n=27) was given 3% methionine on this basis, and divided into model group, folic acid group and HIIT+ folic acid group, with 9 rats per group for 16 weeks. Serum homocysteine (Hcy) , content of plasma malondialdehyde (MDA) , hydroxyl radical (OH-), total antioxidant capacity (T-AOC), activity of glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) were measured, as well as the level of Nitric Oxide (NO), Nitric Oxide Synthase (NOS) and Endothelin 1 (ET-1) . The pathology of abdominal aortas was analyzed.Results Sixteen weeks after intervention, there was no significant difference between HIIT + folic acid group and the control group (P>0.05) . The levels of serum Hcy in the model group, folic acid group and the HIIT+folic acid group were (23.95±3.35) μmol/L,(8.73±0.60) μmol/L, and (6.19±0.34) μmol/L respectively (P<0.05) . Sixteen weeks after intervention, the content of MDA in HIIT+ folic acid group reduced, and there was no significant difference compared with the control group (P>0.05). The level of SOD and GSH-PX increased in HIIT+ folic acid group and folic acid group, and there was a significant difference compared with the model group. There were significant differences in activities of SOD and GSH-PX in HIIT+ folic acid group when compared with folic acid group (P<0.05). Compared with the control group, there were significant differences in levels of ET-1, NOS and NO in folic acid group (P<0.05), while there was no significant difference in the level of ET-1 and NOS between HIIT+folic acid group and control group (P>0.05) . Mild atherosclerotic lesions were observed in the HIIT+folic group. Conclusion High methionine diet can reduce the level of serum Hcy in HHcy rats, and high intensity interval exercise combined with folic acid intervention could reduce the level of serum Hcy, improve oxidative stress state, reduce the injury of endothelial function, and thus to alleviate atherosclerotic lesion.

8.
Japanese Journal of Physical Fitness and Sports Medicine ; : 437-444, 2017.
Article in Japanese | WPRIM | ID: wpr-379399

ABSTRACT

<p>High-intensity interval exercise (IE) leads to greater improvements in the arterial function than continuous exercise at moderate intensity (CE). However, few studies have been performed on the effects of the repetition exercise (RE) on the vascular endothelial function. The purpose of this study was to compare the effects of CE vs. IE vs. RE during aerobic exercise on the vascular endothelial function determined by flow-mediated vasodilation (FMD). Ten healthy male subjects randomly performed 3 trials as follows: CE (20-min cycling at 50%W<sub>max</sub>), IE (10 × 1-min intervals cycling at 75%W<sub>max</sub> interspersed with 1-min intervals cycling at 25%W<sub>max</sub>), and RE (30 × 20-sec intervals cycling at 100%W<sub>max</sub> interspersed with 20-sec intervals at rest). FMD was assessed at rest and 30 and 60 min after each exercise, and then the normalized FMD (nFMD) was calculated from the peak shear rate. The nFMD (a.u.) significant increased 30 min after IE (1.2 ± 0.2 to 3.0 ± 1.0, p<0.05) and increased 30 min after CE (1.0 ± 0.2 to 1.4 ± 0.2, n.s.) and returned to baseline at 60 min after both exercises, while the nFMD decreased 30 min after RE (1.3 ± 0.2 to 1.2 ± 0.1, n.s.) and was sustained at 60 min. The nFMD value at 30 min after IE was significantly greater than that at 30 min after RE (3.0 ± 1.0 versus 1.2 ± 0.1, p<0.05). These results suggest that RE may lead to a less improvement in the vascular endothelial function than CE and IE.</p>

9.
Rev. cuba. salud pública ; 42(4)oct.-dic. 2016. ilus
Article in Spanish | LILACS, CUMED | ID: biblio-845123

ABSTRACT

Introducción: El ejercicio físico contribuye al control glicémico en los pacientes diabéticos y disminuye la aparición de complicaciones. Objetivo: Identificar una modalidad de ejercicio eficiente para los pacientes con diabetes tipo 2 residentes en alturas intermedias. Métodos: Estudio de tipo cuantitativo de carácter cuasi experimental. Se evaluaron 15 pacientes con diagnóstico de diabetes tipo 2, residentes en Pamplona, Colombia, adscritos a una institución prestadora de servicios de salud. La muestra se dividió de forma aleatoria en tres grupos: cinco pacientes para el grupo de ejercicio combinado, cinco para el grupo de ejercicio intermitente de alta intensidad y cinco controles, sin actividad física alguna. Todos los participantes realizaron actividad física sistemática y supervisada durante ocho semanas entre septiembre y octubre de 2014. Se midieron las concentraciones de hemoglobina glicosilada antes y después de la intervención para cada uno de los tres grupos. Resultados: Ambas modalidades de ejercicio disminuyeron significativamente las concentraciones del marcador serológico analizado. Para el ejercicio combinado: antes de la prueba 7,20 por ciento; después de la prueba 6,80 por ciento (-0,40). Para el ejercicio intermitente de alta intensidad: antes 7,50; después 7,08 (-0,42); por el contrario, el grupo control presentó aumento en las concentraciones de hemoglobina glicosilada: antes 8,30 por ciento y después 8,42 por ciento (+0,12). Conclusiones: La modalidad de ejercicio intermitente de alta intensidad disminuye en mayor proporción las concentraciones de hemoglobina glicosilada, de ahí que sea la opción de actividad física más eficiente para los pacientes diabéticos tipo 2 residentes en alturas intermedias(AU)


Introduction: Exercise offers great benefits for glycemic control of diabetic patients and decreases the occurrence of complications. Objective: To identify a more effective and less time-consuming exercise modality for patients with type 2 diabetes who live in middle-altitude areas. Methods: A quantitative, quasi-experimental study which evaluated 15 patients with diagnosis of type 2 diabetes, who lived in Pamplona, Colombia, and were cared for by a health service provider institution called Fundación Médico Preventiva. The sample was randomly divided into three groups, that is, five patients for the combined exercise group, five for the high-intensity interval exercise group and five for the control group which did not perform any physical activity. The two first groups performed systematic supervised physical activity for 8 weeks from September to October, 2014. Levels of glycosylated hemoglobin were measured before and after the intervention in each group. Results: Both types of exercise significantly decreased the levels of glycosylated hemoglobin. For the combined exercise group, the results were pre-test: 7.2 percent and post-test 6.8 percent (-0.34); for the high-intensity interval exercise group: pre-test 7.5 and post-test 7.08 (-0.42) whereas the control group increased their levels of glycosylated hemoglobin: pre-test 8.3 percent and post-test 8.42 percent (+0.12). Conclusions: It was observed that high-intensity interval exercise reduce glycosylated hemoglobin in higher proportions, thus becoming a more effective physical activity option for type 2 diabetic patients(AU)


Subject(s)
Humans , Glycated Hemoglobin , Exercise , Diabetes Mellitus, Type 2/complications , Clinical Trial , Colombia , Exercise Therapy/methods
10.
Chinese Journal of Emergency Medicine ; (12): 617-623, 2016.
Article in Chinese | WPRIM | ID: wpr-497602

ABSTRACT

Objective To investigated the different effect of moderate-intensity continuous training (MCT) and high-intensity interval exercise training (HIT) on ventricular remodeling and mitochondrial homeostasis after acute myocardial infarction (AMI).Methods The AMI rat model was achieved by ligating coronary artery.The AMI and sham operation rats were randomly (random number) divided into four groups:sham operation group (Sham),AMI control group (AMI),AMI MCT group (AMI + M),and AMI HIT group (AMI + H).Animals in the AMI + M and AMI + H groups underwent 4 weeks MCT and HIT respectively.Five weeks after AMI,hemodynamic changes,mitochondrial bioenergetics,and PINK1,Beclinl,Mfn2,Drp1,Tfam,COXⅣ,PGC-1α were detected.Results Comparing with AMI group,in AMI + M and AMI + H groups,Beclin1,PINK1,Mfn2 and PGC-1α expression elevated significantly (P <0.05 or P <0.01),whereas ROS generation and Drp1 expression showed dramatic decrease (P < 0.05 or P<0.01).In addition,in AMI + H group,±dp/dt max,mitochondrial membrane potential,ATP synthesis activity,Tfam and COXⅣ expression improved significantly (P < 0.05).Comparing with AMI + M group,in AMI + H group,± dp/dt max,PGC-1α,Tfam and COX Ⅳ expression improved significantly (P < 0.05).Conclusions HIT is superior to MCT for ameliorating ventricular remodeling and mitochondrial homeostasis after AMI.

11.
Japanese Journal of Physical Fitness and Sports Medicine ; : 475-480, 2014.
Article in English | WPRIM | ID: wpr-375859

ABSTRACT

Interval training has a beneficial effect for treating the cardiovascular disease. However, it is not clarify the effects of different exercise intensity and duration on arterial function. In the present study, we evaluated the effect of acute short-term high and moderate-intensity interval exercise on pulse wave velocity. Thirteen healthy men were randomly assigned to perform both acute interval exercise (IE; cycling for 24.6 min at 80%VO<sub>2</sub>max and 50%VO<sub>2</sub>max) and acute continuous moderate-intensity exercise (CME; cycling for 30 min at 50%VO<sub>2</sub>max). The IE and CME protocols were designed such that the exercises resulted in the same workload during each session. The brachial systolic and diastolic blood pressure (SBP and DBP), and brachial to ankle pulse wave velocity (baPWV) were obtained in the supine position using an automatic pulse wave form analyzer at pre- and post-exercise. In IE, baPWV at post-exercise decreased significantly compared with pre-exercise value (1181.9±119.2 cm・sec<sup>-1</sup> vs. 1108.4±109.4 cm・sec<sup>-1</sup>, p<0.01). In CME, however, it was not significantly different between pre- and post-exercise values (1173.5±137.1 cm・sec<sup>-1</sup> vs. 1164.8±96.0 cm・sec<sup>-1</sup>, p=ns). No significant differences in SBP and DBP were found both protocols. These results suggest that acute short-term high and moderate-intensity interval exercise was more effective in reducing baPWV compared with acute continuous exercise.

12.
Rev. bras. med. esporte ; 19(3): 155-159, maio-jun. 2013. graf, tab
Article in Portuguese | LILACS | ID: lil-683303

ABSTRACT

INTRODUÇÃO: A frequência cardíaca (FC) no teste anaeróbio máximo de corrida (MART) expressa o comportamento autonômico cardíaco em exercício. Ainda não foi investigado se tais respostas cronotrópicas apresentam associação com o desempenho aeróbio e anaeróbio. OBJETIVOS: Descrever a resposta cronotrópica cardíaca durante o MART nos segundos iniciais de estímulo (FC ON) e de recuperação (FC OFF) e estabelecer a associação entre as variáveis cronotrópicas com o desempenho aeróbio e anaeróbio. MÉTODOS: Foram voluntários 13 homens assintomáticos e fisicamente ativos, com 25,1 ± 4,9 anos, 76,8 ± 12,5 kg, 178,4 ± 9,0 cm e 50,6 ± 4,1 mL×kg‑1×min‑1. Na primeira visita, após a anamnese e medidas antropométricas, foi realizado um teste cardiopulmonar de exercício (TCPE) com monitoração direta dos gases expirados. Na segunda visita, foi feita uma familiarização ao MART e na terceira, o teste de MART conduzido até a exaustão. RESULTADOS: A FC de recuperação (58 ± 20 bpm) comparada à FC de pico alcançada no primeiro e no último estágio de MART (39 ± 14 bpm) apresentou maior inclinação, resultando em maior amplitude de variação ao longo do teste, caracterizando diferenças significativas (P = 0,0017). A FC ON apresentou entre o momento inicial, meio e final do MART diferenças significativas (inicial versus final, p = 0,007). Para FC OFF foram encontradas diferenças significativas do início com o meio (p = 0,035) e do início com o final (p = 0,005) do teste. As correlações entre as variáveis cronotrópicas e de desempenho não apresentaram significância estatística (P < 0,05), assim como com as variáveis de desempenho. CONCLUSÃO: O MART parece ser um modelo de sobrecargas fisiológicas adequado para investigação da modulação autonômica cardíaca. Observou-se atuação do sistema parassimpático mesmo em cargas supramáximas até o final do teste.


INTRODUCTION: Heart rate (HR) in maximal anaerobic running test (MART) expresses the cardiac autonomic behavior in exercise. It has not been investigated whether such responses are associated with chronotropic aerobic and anaerobic performance. OBJECTIVE: To describe the cardiac chronotropic response during the MART in seconds of stimulation (HR ON) and recovery (HR OFF), and establish the association between chronotropic variables with aerobic and anaerobic performance. METHODS: Thirteen male volunteers were asymptomatic and physically active, with 25.1 ± 4.9 years, 76.8 ± 12.5 kg, 178.4 cm and 50.6 ± 9.0 ± 4.1 mL×kg-1×min-1. On the first visit after the interview and anthropometric measurements, we performed a cardiopulmonary exercise testing (TCPE) with direct monitoring of expired gases. The second visit was carried to familiarize the MART and the third, the test was performed until exhaustion MART. RESULTS: Heart rate recovery (58 ± 20 bpm) compared to the peak HR achieved in the first and last stage of MART (39 ± 14 bpm) had a higher slope, resulting in greater range of variation over the test, characterizing differences (P = 0.0017). The HR ON presented between the time the initial, middle and end of the MART significant differences (start versus final, p = 0.007). To HR OFF significant differences were found starting with the middle (p = 0.035) and the starting to the final (p = 0.005) test. The chronotropic correlations between variables, including decrease in HR, and TCPE performance were not statistically significant (P < 0.05), as nor as the performance variables. CONCLUSION: The MART model seems to be a physiological overload suitable for investigation of cardiac autonomic modulation. There was action of the parasympathetic system even in supramaximal loads by the end of the test.

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