436 resultados para Repouso hibernal
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Introduction: The aging process causes quantitative and qualitative changes in sleeping. Such changes affects more than half of the adults above 65 years old, that live in the community and 70% of the institutionalized, a great negative impact in their quality of life. One of the pathological displays of aging, that share some characteristics with sleeping disorders and predict similar results, is the Frailty Syndrome, that characterize the most weakened and vulnerable elderly. The way sleeping disorders play a role in the frailty pathogeneses remains uncertain. Objective: Evaluate the relation between the sleeping and the frailty syndrome on institutionalized elderly. Methodology: A transversal study was performed with 69 elderly in institutions in the city of João Pessoa PB. Were used the Pittsburgh Sleeping Quality Index and actigraphy to subjective and objective variables, respectively, and questionnaires and specific tests to frailty phenotype variant (Fried Frailty Criteria). In the statistic analysis were used the Pearson correlation test, Chi Square and One-way ANOVA test, with Tukey-Krammer posttest. Subsequently, a Simple Linear Regression model was built. On every statistical analysis were considered a confidence interval of 95% and a p < 0,05. Results: The sample was characterized by the prevalence of the frail (49,3%), women (62,3%), single (50,7%) and 77,52 (±7,82).The frail elderly obtained the worst sleeping quality 10,37 (±4,31) (f = 4,15, p = 0,02), when compared with the non-frail. The sleep latency influenced more the frailty (R2 = 0,13, β standard = 1,76, β = 0,41, p = 0,001). Weren t found differences between the standard resting-activity variable and the frailty phenotype categories. Conclusion: Sleeping alterations, including bad sleeping quality, prolonged sleep latency, low sleep efficiency and day drowsiness, influenced the frailty in institutionalized elderly
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Objective:To analyze the immediate effects of the Kinesio Taping® application on the quadriceps neuromuscular performance, postural balance and lower limb function in healthy subjects. Materials andmethods:This is a randomized, controlled, blinded clinical trial. Sixtyfemale volunteers(age: 23.3±2.5 years old, BMI: 22.2±2.1kg/m2)wererandomly assigned intothreegroups with20memberseach,and performedone of these threeprotocols: control -10 minutesof rest,experimental 1- patch application ontherectusfemoris (RF), vastuslateralis(VL) and vastusmedialis(VM) and experimental 2-KT application on the same muscles. Allunderwent an evaluationfor singleand triple hop distance, postural balance (baropodometry), joint position sense(JPS), peak torque (concentric and eccentricevaluation at 60°/s)and electromyographic activityof VL,before andafter intervention.Results: There wasasignificant increasein the jump distanceof thethreestudied groups,with no differencebetween groups.There were nosignificant changesin postural balance,JPS, concentricpeak torqueand RMSof the VLin none of the groups. There was a reduction ineccentricpeak torquein all groups, without differencesbetween groups.Conclusion:The KT application on the RF, VL and VMmusclesis not able tosignificantly improvelower limbfunction and postural balance, as well as the kneeextensor peaktorque, JPSand the VL muscleactivation amplitudeof healthy women.
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Objectives: To evaluate how to develop dynamic hyperinflation (DH) during exercise, the influence of pursed-lip breathing in (PLB) on breathing pattern and operating volume in patients with asthma. Methods: We studied 12 asthmatic patients in three moments: (1) anthropometry and spirometry, (2) submaximal incremental cycle ergometer test in spontaneous breathing and (3), submaximal incremental test on a cycle ergometer with PLB using the Opto-electronic plethysmography. Results: Evaluating the end-expiratory lung volume (EEV) during submaximal incremental test in spontaneous breathing, patients were divided into euvolume and hyperinflated. The RFL has increased significantly, the variation of the EEV group euvolume (1.4L) and decreased in group hyperinflated (0.272L). In group volume observed a significant increase of 140% in Vt at baseline, before exercise, comparing the RFL and spontaneous breathing. Hyperinflated group was observed that the RFL induced significant increases of Vt at all times of the test incremental baseline, 50%, 100% load and 66% recovery, 250%, 61.5% and 66% respectively. Respiratory rate decreased significantly with PLB at all times of the submaximal incremental test in the group euvolume. The speed of shortening of inspiratory muscles (VtRcp/Ti) in the hyperinflated increased from 1.6 ± 0.8L/s vs. 2.55 ± 0.9L/s, whereas in the RFL euvolume group ranged from 0.72 ± 0.31L/s vs. 0.65 ± 0.2L/s. The velocity of shortening of the expiratory muscles (VtAb/Te) showed similarity in response to RFL. In group hyperinflated varied vs. 0.89 ± 0.47 vs. 0.80 ± 0.36 and ± 1.17 ± 1L vs. 0.78 ± 0.6 for group euvolume. Conclusion: Different behavior in relation to EEV in patients with moderate asthma were observed, the HD and decreased EEV in response to exercise. The breathing pattern was modulated by both RFL performance as at home, making it more efficient
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Ayahuasca is psychotropic beverage that has been used for ages by indigenous populations in South America, notably in the Amazon region, for religious and medicinal purposes. The tea is obtained by the decoction of leaves from the Psychotria viridis with the bark and stalk of a shrub, the Banisteriopsis caapi. The first is rich in N-N-dimethyltryptamine (DMT), which has an important and well-known hallucinogenic effect due to its agonistic action in serotonin receptors, specifically 5-HT2A. On the other hand, β-carbolines present in B. caapi, particularly harmine and harmaline, are potent monoamine oxidase inhibitors (MAOi). In addition, the tetrahydroharmine (THH), also present in B. caapi, acts as mild selective serotonin reuptake inhibitor and a weak MAOi. This unique composition induces a number of affective, sensitive, perceptual and cognitive changes in individuals under the effect of Ayahuasca. On the other hand, there is growing interest in the Default Mode Network (DMN), which has been consistently observed in functional neuroimaging studies. The key components of this network include structures in the brain midline, as the anterior medial frontal cortex, ventral medial frontal cortex, posterior cingulate cortex, precuneus, and some regions within the inferior parietal lobe and middle temporal gyrus. It has been argued that DMN participate in tasks involving self-judgments, autobiographical memory retrieval, mental simulations, thinking in perspective, meditative states, and others. In general, these tasks require an internal focus of attention, hence the conclusion that the DMN is associated with introspective mental activity. Therefore, this study aimed to evaluate by functional magnetic resonance imaging (fMRI) changes in DMN caused via the ingestion of Ayahuasca by 10 healthy subjects while submitted to two fMRI protocols: a verbal fluency task and a resting state acquisition. In general, it was observed that Ayahuasca causes a reduction in the fMRI signal in central nodes of DMN, such as the anterior cingulate cortex, the medial prefrontal cortex, the posterior cingulate cortex, precuneus and inferior parietal lobe. Furthermore, changes in connectivity patterns of the DMN were observed, especially a decrease in the functional connectivity of the precuneus. Together, these findings indicate an association between the altered state of consciousness experienced by individuals under the effect of Ayahuasca, and changes in the stream of spontaneous thoughts leading to an increased introspective mental activity
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
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The damselfish, Stegastes fuscus Cuvier, 1830 (Osteichthyes: Perciformes: Pomacentridae), is abundant in the coastal reefs of Búzios Beach, Rio Grande do Norte, Brazil and they play an important role in the reef community ecology. The present study investigated the feeding strategy of this species considering the food habits and morfo-histology of the digestive tract. Influence of the environmental correlates such as temperature, rainfall and luminosity in the tidal rock pools were studied. The fish were captured on a monthly basis from September 2004 to August 2005, during which period 842 individuals of S. fuscus were captured, 125 males, 437 females and 280 individuals without sex identification. The sex ratio observed was 1 M : 3,5 F. The total body length of males varied from 3.6 to 11.3 cm, with a mean of 7.77 cm; that of females varied from 2.9 to 11.4 cm, with a mean of 7.85 cm, and that of sex grouped individuals varied from 2.9 to 11.4 cm, with a mean of 7.83. However, there was no difference between males and females in total body length. This species presented a positive alometric growth and the equations obtained for the relation between body mass and total body length were: Wt =0,0174Lt 3,1123 for males; Wt =0,0137Lt 3,2294 for females and Wt = 0,0148Lt 3.1928 for sex grouped individuals. The relation between total body length and standard length was L t = 1 ,3223Ls + 0,1527 for sex grouped individual s. February to August was associated to a long period of gonadal resting. The fish spawned during January and in September -October. The frequency of fish with empty stomachs occurred during August to December, whereas frequency of fish with food contents i n stomachs occurred during January to July. This species is considered as a preferential herbivore based on the volume of macroalgae in its diet composition. The morfo -histological aspects of S. fuscus confirm herbivory. Among the environmental factors con sidered only rainfall showed a correlation with the feeding habits of this species
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Parkinson's disease (PD) is one of the most common neurodegenerative brain disorders and is characterized primarily by a progressive degeneration of dopaminergic neurons nigroestriatais. The main symptoms of this disease are motor alterations (bradykinesia, rigidity, tremor at rest), which can be highly disabling in advanced stages of the condition. However, there are symptomatic manifestations other than motor impairment, such as changes in cognition, mood and sensory systems. Animal models that attempt to mimic clinical features of PD have been used to understand the behavioral and neural mechanisms underlying neurophysiological disturbance of this disease. However, most models promote an intense and immediate motor impairment, consistent with advanced stages of the disease, invalidating these studies for the evaluation of its progressive nature. The administration of reserpine (a monoamine depletor) in rodents has been considered an animal model for studying PD. Recently we found that reserpine (in doses lower than those usually employed to produce the motor symptoms) promotes a memory deficit in an aversive discrimination task, without changing the motor activity. It was suggested that the administration of this drug in low doses can be useful for the study of memory deficits found in PD. Corroborating this data, in another study, acute subcutaneous administration of reserpine, while preserving motor function, led to changes in emotional context-related (but not neutral) memory tasks. The goal of this research was to study the cognitive and motor deficits in rats repeatedly treated with low doses of reserpine, as a possible model that simulates the progressive nature of the PD. For this purpose, 5-month-old male Wistar rats were submitted to a repeated treatment with vehicle or different doses of reserpine on alternate days. Cognitive and motor parameters and possible changes in neuronal function were evaluated during treatment. The main findings were: repeated administration of 0.1 mg / kg of reserpine in rats is able to induce the gradual appearance of motor signs compatible with progressive features found in patients with PD; an increase in striatal levels of oxidative stress and changes in the concentrations of glutamate in the striatum were observed five days after the end of treatment; in animals repeatedly-treated with 0. 1 mg/kg, cognitive deficits were observed only after the onset of motor symptoms, but not prior to the onset of these symptoms; 0.2 mg / kg reserpine repeated treatment has jeopardized the cognitive assessment due to the presence of severe motor deficits. Thus, we suggest that the protocol of treatment with reserpine used in this work is a viable alternative for studies of the progressive appearance of parkinsonian signs in rats, especially concerning motor symptoms. As for the cognitive symptoms, we suggest that more studies are needed, possibly using other behavioral models, and / or changing the treatment regimen
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Circadian rhythms are variations in physiological processes that help living beings to adapt to environmental cycles. These rhythms are generated and are synchronized to the dark light cycle through the suprachiasmatic nucleus. The integrity of circadian rhythmicity has great implication on human health. Currently it is known that disturbances in circadian rhythms are related to some problems of today such as obesity, propensity for certain types of cancer and mental disorders for example. The circadian rhythmicity can be studied through experiments with animal models and in humans directly. In this work we use computational models to gather experimental results from the literature and explain the results of our laboratory. Another focus of this study was to analyze data rhythms of activity and rest obtained experimentally. Here we made a review on the use of variables used to analyze these data and finally propose an update on how to calculate these variables. Our models were able to reproduce the main experimental results in the literature and provided explanations for the results of experiments performed in our laboratory. The new variables used to analyze the rhythm of activity and rest in humans were more efficient to describe the fragmentation and synchronization of this rhythm. Therefore, the work contributed improving existing tools for the study of circadian rhythms in mammals
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
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The sleep onset and offset delay at adolescence in relation to childhood. Besides biological causes, some external factors as academic obligations and socialization contributes, increasing the burden of school and socialization. However, morning school schedules reduce sleep duration. Besides light strong effect, studies in humans have indicated that exercise influence circadian synchronization. To evaluate the effect of the morning exercise under sunlight on sleep-wake cycle (SWC) of adolescents, 160 high school students (11th year) were exposed to the following conditions: lesson in usual classroom (Group C), lesson in swimming pool exposed to sunlight (Group E), half of them carrying through physical activity (EE) and the other resting (EL). Each experimental group met two stages: assessment of SWC 1 week before and 1 week during the intervention, which was held in Monday and Wednesday between 7:45 and 8:30 am. In the baseline, there were applied the questionnaires "Health and Sleep" and cronotype evaluation (H & O). In addition, students were evaluated before and during the intervention by "Sleep Diary", "Karolinska Sleepiness Scale" (KSS), Psychomotor Vigilance Test (PVT) and actimetry. During the intervention, there was a delay in wake-up time on the weekend and a trend to greater sleep duration on week for the three groups. At the weekend, only the groups EE and EL increased sleep duration. There was no difference in bedtime, irregularity of sleep schedules and nap variables. The sleepiness showed a circadian pattern characterized by higher alertness levels at 11:30 am and sleepiness levels at bedtime and wake-up time on week. On weekends there were higher levels of alertness in these times. In the days of intervention, there was an increase of sleepiness at 11:30 am for groups EL and EE, which may have been caused by a relaxing effect of contact with the water of the pool. In addition, the group EE showed higher alert levels at 14:30 pm on Monday and at 8:30 am in the Wednesday, possibly caused by exercise arousal effect. The reaction time assessed through the TPV did not vary between the stages. The sleep quality improved in the three groups in the second stage, making impossible the evaluation of intervention effect. However, the sleep quality increased on Monday and Tuesday only on the group EE. From the results, it is suggested that the intervention promoted effects on the sleepiness at some day hours. In other SWC variables there were no effects, possibly due to a large SWC irregularity on weekends. Thus, the evaluation of higher weekly frequency EF is necessary, since only two days were insufficient to promote greater effect on adolescents SWC
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Social behavior of Guiana dolphins, Sotalia guianensis, at Pipa Beach, RN, Brazil: dynamics, sequence, breathing synchrony, and responses to dolphin watching. Social animals form groups that can range from temporary to permanent. Depending on the nature of the social relationships developed between individuals, groups present a particular social organization and the effect of these interactions shapes the activity patterns of these animals. This study investigates: (i) fission-fusion dynamics of Guiana dolphins, through the analysis of three dimensions of the social system (variation in spatial cohesion, variation in size and composition of groups), (ii) sequence, routine and behavioral stability, (iii) breathing intervals in synchronized groups and (iv) behavioral responses of the animals to dolphin watching. Systematic observations of Guiana dolphins were made from a platform located in cliffs about 25 m above sea level that surround Madeiro Bay, Pipa Beach. Sampling occurred from December 2007 to February 2009 between 0600 h and 1600 h, and the groups of Guiana dolphins were investigated according to their size (alone and group) and composition (adults, adults and juveniles, and adults and calves). According to the analysis of fission-fusion dynamics, Guiana dolphin groups frequently changed their composition, modifying their patterns of spatial grouping and cohesion every 20 minutes on average. More than 50% of the individuals maintained a distance of up to 2 m from other group members and new individuals were attracted to the group, especially during feeding, leaving it for foraging. Large groups were more unstable than small, while groups containing only adults were more stable than groups of adults and juveniles. According to the Z-score analysis to investigate the sequence and behavioral routine, lone individuals were more ! .7! ! involved in foraging and feeding, while resting was more common in groups. Foraging and feeding were more common in homogeneous groups (individuals of the same age class), while heterogeneous groups (different age classes) were often involved in socialization, displaying a broader behavioral repertoire. Foraging and resting behavior presented higher stability (continuous duration in minutes) than the other behaviors. The analysis of breathing intervals in synchronized groups showed significant differences depending on type of behavior, composition and area preference. During resting, breathing intervals were of longer duration, and groups with calves showed shorter breathing intervals than groups without calves. Lone individuals also preferred areas called corral , often used for the entrapment of fishes. The Markov chain analysis revealed behavioral changes in the presence of boats, according to the type of group composition. Groups composed of adults presented decreased resting and increased in traveling during the presence of boats. Groups of adults and juveniles showed a massive reduction of socialization, while the behavior transition probability traveling-traveling was higher in groups of adults and calves. In the presence of the boats, stability of resting was reduced by one third of its original duration and traveling more than doubled. The behavioral patterns analyzed are discussed in light of socio-ecological models concerning costs and benefits of proximity between individuals and behavioral optimization. Furthermore, significant changes in behavioral patterns indicate that Guiana dolphins, at Pipa Beach, have suffered the effects of tourism as a result of violation of rules of conduct established for the study area
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One of the main environmental cues for the adjustment of temporal organization of the animals is the light-dark cycle (LD), which undergoes changes in phase duration throughout the seasons. Photoperiod signaling by melatonin in mammals allows behavioral changes along the year, as in the activity-rest cycle, in mood states and in cognitive performance. The aim of this study was to investigate if common marmoset (Callithrix jacchus) exhibits behavioral changes under short and long photoperiods in a 24h cycle, assessing their individual behaviors, vocal repertoire, exploratory activity (EA), recognition memory (RM) and the circadian rhythm of locomotor activity (CRA). Eight adult marmosets were exposed to a light-dark cycle of 12:12; LD 08:16; LD 12:12 and LD 16:08, sequentially, for four weeks in each condition. Locomotor activity was recorded 24h/day by passive infrared motion detectors above the individual cages. A video camera system was programmed to record each animal, twice a week, on the first two light hours. From the videos, frequency of behaviors was registered as anxiety-like, grooming, alert, hanging position, staying in nest box and feeding using continuous focal animal sampling method. Simultaneously, the calls emitted in the experimental room were recorded by a single microphone centrally located and categorized as affiliative (whirr, chirp), contact (phee), long distance (loud shrill), agonistic (twitter) and alarm (tsik, seep, see). EA was assessed on the third hour after lights onset on the last week of each condition. In a first session, marmosets were exposed to one unfamiliar object during 15 min and 24h later, on the second session, a novel object was added to evaluate RM. Results showed that long days caused a decreased of amplitude and period variance of the CRA, but not short days. Short days decreased the total daily activity and active phase duration. On long days, active phase duration increased due to an advance of activity onset in relation to symmetric days. However, not all subjects started the activity earlier on long days. The activity offset was similar to symmetric days for the majority of marmosets. Results of EA showed that RM was not affected by short or long days, and that the marmosets exhibited a decreased in duration of EA on long days. Frequency and type of calls and frequency of anxiety-like behaviors, staying in nest box and grooming were lower on the first two light hours on long days. Considering the whole active phase of marmosets as we elucidate the results of vocalizations and behaviors, it is possible that these changes in the first two light hours are due to the shifting of temporal distribution of marmoset activities, since some animals did not advance the activity onset on long days. Consequently, the marmosets mean decreased because the sampling was not possible. In conclusion, marmosets synchronized the CRA to the tested photoperiods and as the phase angle varied a lot among marmosets it is suggested that they can use different strategies. Also, long days had an effect on activity-rest cycle and exploratory behaviors
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The study of the motivation to practice physical activities is relevant once through this it is possible to develop intervention strategies for sedentary population. In this way, the present dissertation aimed to adapt and validate for the Brazilian context the Motives for Physical Activity Measure Revised (MPAM-R). It was investigated yet the relation of some socio-demographic variables (age, gender, Body Mass Index - BMI, types of physical activity; way to practice and time of practice) and the participants means in the motives studied. The physical activity (PA) is defined as any bodily movement produced by skeletal muscles resulting in energy expenditure above the basal level. However, in the present study it was considered motivation for two types of PA: the physical exercises and sports. The Self-Determination Theory (SDT) underlay this research, once it has been used in the sportive context, beyond the facto of it was used as theoretical base to the development of MPAM-R. To attain the proposed goals, it was accomplished translations to Portuguese of the original English scale. Next, was carried out the semantic analysis and the judge analysis. For the empirical analysis of items, participated 309 practitioner of PA, classified in physical exercises practitioners and sports practitioners, with ages between 16 and 74 years, distributed equally by sex. They answered the final version in Portuguese of the MPAM-R and socio-demographic questions. The data was collected in Natal/RN, where the researcher approached people in some places where the PA is practiced, following she communicated that their involvement will be spontaneous and their responses will be confidential. The obtained results pointed the confirmation of the existence of five factors in the final version of the instrument, that was composed by 26 items that presented the following statistics indexes: x² (289) = 757.75, p < 0.000, x²/DF = 2.62, with GFI of 0.83, AGFI of 0.80 and RMSEA of 0.07. The reliability (Cronbach Alpha) of the complete instrument was 0.90, and the indexes of each factor were considered satisfactory too: Enjoyment (α = 0.88), Health (α = 0.84), Appearance (α = 0.79), Competence (α = 0.85) and Social (α = 0.75). It was observed that, in general, the main motive presented by the participants to practice PA was Health. It was verified yet, that women and aged had a higher mean in the Health factor; among the exercise practitioners was found a higher mean in the Appearance factor; and a higher mean in the Social factor was found among those that practice PA with accompaniment. It was concluded that the MPAM-R presented satisfactory psychometric parameters, became it useful in futures researches. Moreover, proposed the accomplishment of new studies that considered others variables to the intent of the better understanding of motivation to practice physical activity
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Drying of fruit pulps in spouted beds of inert particles has been indicated as a viable technique to produce fruit powders. Most of the processes employed to produce dried fruit pulps and juices, such as Foam Mat, encapsulation by co-crystallization and spray drying utilize adjuvant and additives (such as thickeners, coating materials, emulsifiers, acidulants, flavors and dyes), which is not always desirable. The fruit pulp composition exerts an important effect on the fruit powder production using a spouted bed. In the study by Medeiros (2001) it was concluded that lipids, starch and pectin contents play an important role on the process performance, enhancing the powder production; however, the drying of fruit pulps containing high content of reducing sugars (glucose and fructose) is practically unviable. This work has the objective of expanding the studies on drying of fruit pulps in spouted bed with aid of adjuvant (lipids, starch and pectin) aiming to enhance the dryer performance without jeopardizing the sensorial quality of the product. The optimum composition obtained by Medeiros (2001) was the basis for preparing the mixtures of pulps. The mixture formulations included pulps of mango (Mangifera indica), umbu (Spondias tuberosa) and red mombin (Spondia purpurea) with addition of cornstarch, pectin and lipids. Different products were used as lipids source: olive and Brazil nut oils, coconut milk, heavy milk, powder of palm fat and palm olein. First of all, experiments were conducted to define the best formulation of the fruit pulps mixture. This definition was based on the drying performance obtained for each mixture and on the sensorial characteristics of the dry powder. The mixture formulations were submitted to drying at fixed operating conditions of drying and atomizing air flow rate, load of inert particles, temperature and flow rate of the mixture. The best results were obtained with the compositions having powder of palm fat and palm olein in terms of the drying performance and sensorial analysis. Physical and physicochemical characteristics were determined for the dry powders obtained from the mixtures formulations. Solubility and reconstitution time as well as the properties of the product after reconstitution were also evaluated. According to these analyses, the powder from the mixtures formulations presented similar characteristics and compatible quality to those produced in other types of dryers. Considering that the palm olein is produced in Brazil and that it has been used in the food industry substituting the palm fat powder, further studies on drying performance were conducted with the composition that included the palm olein. A complete factorial design of experiments 23, with three repetitions at the central point was conducted to evaluate the effects of the air temperature, feeding flow rate and intermittence time on the responses related to the process performance (powder collection efficiency, material retained in the bed and angle of repose of the inert particles after the process) and to the product quality (mean moisture content, loss of vitamin C and solubility). Powder production was uniform for the majority of the experiments and the higher efficiency with lower retention in the bed (59.2% and 1.8g, respectively) were obtained for the air temperature of 80°C, mixture feed rate of 5ml/min in intervals of 10 min. The statistical analysis of the results showed that the process variables had individual or combined significant influences on the powder collection efficiency, material retention in the bed, powder moisture content and loss of vitamin C. At the experimental ranges of this work, the angle of repose and solubility were not influenced by the operating variables. From the results of the experimental design, statistical models were obtained for the powder moisture content and loss of vitamin C
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Background: The literature reports that the eccentric muscular action produces greater force and lower myoelectric activity than the concentric muscular action, while the heart rate (HR) responses are bigger during concentric contraction. Objectives: To investigate the maximum average torque (MAT), surface electromyographic (SEMG) and the heart rate (HR) responses during different types of muscular contraction and angular velocities in older men. Methods: Twelve healthy men (61.7 +/- 1.6years) performed concentric (C) and eccentric (E) isokinetic knee extension-flexion at 60 degrees/s and 120 degrees/s. SEMG activity was recorded from vastus lateralis muscle and normalized by Root Mean Square-RMS (mu V) of maximal isometric knee extension at 60 degrees. HR (beats/min) and was recorded at rest and throughout each contraction. The data were analyzed by the Friedman test for repeated measures with post hoc Dunn's test (p<0.05). Results: The median values of MAT (N.m/kg) was smaller and the RMS (mu V) was larger during concentric contraction (C60 degrees/s=2.80 and 0.99; C120 degrees/s=2.46 and 1.0) than eccentric (E60 degrees/s=3.94 and 0.85; E120 degrees/s=4.08 and 0.89), respectively. The HR variation was similar in the four conditions studied. Conclusion: The magnitude of MAT and RMS responses in older men were dependent of the nature of the muscular action and independent of the angular velocity, whereas HR response was not influenced by these factors.