The functional role of cardiac activity in perception and action.

SKORA, L.I., J.J.A. LIVERMORE and K. Roelofs. The functional role of cardiac activity in perception and action. NEUROSCI BIOBEHAV REV X(X) XXX-XXX, 2022. Patterns of cardiac activity continuously vary with environmental demands, accelerating or decelerating depending on circumstances. Simultaneously, cardiac cycle affects a host of higher-order processes, where systolic baroreceptor activation largely impairs processing. However, a unified functional perspective on the role of cardiac signal in perception and action has been lacking. Here, we combine the existing strands of literature and use threat-, anticipation-, and error-related cardiac deceleration to show that deceleration is an adaptive mechanism dynamically attenuating the baroreceptor signal associated with each heartbeat to minimise its impact on exteroceptive processing. This mechanism allows to enhance attention afforded to external signal and prepare an appropriate course of action. Conversely, acceleration is associated with a reduced need to attend externally, enhanced action tendencies and behavioural readjustment. This novel account demonstrates that dynamic adjustments in heart rate serve the purpose of regulating the level of precision afforded to internal versus external evidence in order to optimise perception and action. This highlights that the importance of cardiac signal in adaptive behaviour lies in its dynamic regulation.

Evaluación de la carga fisiológica de trabajo con fines ergonómicos en actividades mineras que se desarrollan en altura geográfica / Evaluation of physiological workload for ergonomic purposes in mining activities performed in geographical altitude

Desde la perspectiva de la Ergonomía y la Fisiología del Trabajo, hay escaso conocimiento acerca del impacto que trabajos de alta demanda energética, efectuados en altura geográfica, tienen sobre el bienestar laboral de quienes los ejecutan. La evaluación de la respuesta fisiológica durante trabajos reales en altura no es simple. Las dos variables más utilizadas para cuantificar la intensidad de los esfuerzos son el consumo de oxígeno (VO2) y la frecuencia cardíaca (fC). La primera técnica es compleja, mientras que la segunda permite seguimientos de jornadas completas sin alterar el trabajo. Además, cuando se asocia a las actividades que la persona realiza, permite identificar cargas peak y proponer soluciones para evitarlas o reducirlas. En consecuencia, el objetivo del presente estudio es analizar y proponer una metodología simple, de bajo costo, para la evaluación de la carga fisiológica, combinando estudios de tiempo y medición de frecuencia cardíaca, en trabajadores que se desempeñan en altura geográfica. En cuanto a métodos, el estudio se efectuó en 23 trabajadores que tenían entre 26 y 60 años de edad. A cada uno de ellos se le hizo un seguimiento de jornada con registros continuos y sincronizados de tiempo y fC. Los principales resultados revelaron una correlación inversamente proporcional entre edad y frecuencia cardíaca peak. Al mismo tiempo, la metodología propuesta se demostró muy útil para identificar cargas de altas demandas fisiológicas, como apoyo para la búsqueda de soluciones ergonómicas. En síntesis, se concluye que la metodología propuesta, asociada a un enfoque de ergonomía participativa, permite abordar las tareas más críticas, identificar la intensidad de los esfuerzos y proponer soluciones en los casos de mayor sobrecarga.

From the perspective of Ergonomics and Work Physiology, there is little knowledge about the impact of high energy demand, performed in geographic altitude, over the well-being of their workers. The assessment of the physiological answer during real works in altitude is not a simple task. The two more used variables to quantify the intensity of the efforts are the oxygen intake (VO2) and cardiac frequency (fC). The first technic is complex, while the second allows a follow-up of the complete workdays without disturbing the work. Furthermore, when activities are associated with the person that performs it, it allows us to identify charges peak and propose answers to avoid and reduce them. As result, the aim of the present study is to analyze and propose a simple methodology, of low cost, to assess the physiological load, combining time studies and measurement of cardiac frequency, in workers performing in geographic altitudes. As for methods, the study was performed in 23 workers from 26 to 60 years old. A workday follow-up was performed to each of the workers with continuous and time-synchronized registers and fC. The main results displayed an inversely proportional link between age and peak cardiac frequency. At the same time, the proposed methodology proved to be useful to identify loads of high physiological demands, like support for the seek of ergonomic solutions. In summary, we concluded that the proposed methodology, associated with a collaborative ergonomic approach, allowing us to address the most critical tasks, identify the intensity of the efforts, and propose solutions in the cases of greater overload.

A multidimensional and multi-feature framework for cardiac interoception.

Interoception (the sensing of inner-body signals) is a multi-faceted construct with major relevance for basic and clinical neuroscience research. However, the neurocognitive signatures of this domain (cutting across behavioral, electrophysiological, and fMRI connectivity levels) are rarely reported in convergent or systematic fashion. Additionally, various controversies in the field might reflect the caveats of standard interoceptive accuracy (IA) indexes, mainly based on heartbeat detection (HBD) tasks. Here we profit from a novel IA index (md) to provide a convergent multidimensional and multi-feature approach to cardiac interoception. We found that outcomes from our IA-md index are associated with -and predicted by- canonical markers of interoception, including the hd-EEG-derived heart-evoked potential (HEP), fMRI functional connectivity within interoceptive hubs (insular, somatosensory, and frontal networks), and socio-emotional skills. Importantly, these associations proved more robust than those involving current IA indexes. Furthermore, this pattern of results persisted when taking into consideration confounding variables (gender, age, years of education, and executive functioning). This work has relevant theoretical and clinical implications concerning the characterization of cardiac interoception and its assessment in heterogeneous samples, such as those composed of neuropsychiatric patients.

Coupling of Blood Pressure and Subarachnoid Space Oscillations at Cardiac Frequency Evoked by Handgrip and Cold Tests: A Bispectral Analysis.

The aim of the study was to assess blood pressure-subarachnoid space (BP-SAS) width coupling properties using time-frequency bispectral analysis based on wavelet transforms during handgrip and cold tests. The experiments were performed on a group of 16 healthy subjects (F/M; 7/9) of the mean age 27.2 ± 6.8 years and body mass index of 23.8 ± 4.1 kg/m2. The sequence of challenges was first handgrip and then cold test. The handgrip challenge consisted of a 2-min strain, indicated by oral communication from the investigator, at 30% of maximum strength. The cold test consisted of 2 min of hand immersion to approximately wrist level in cold water of 4 °C, verified by a digital thermometer. Each test was preceded by 10 min at baseline and was followed by 10-min recovery recordings. BP and SAS were recorded simultaneously. Three 2-min stages of the procedure, baseline, test, and recovery, were analyzed. We found that BP-SAS coupling was present only at cardiac frequency, while at respiratory frequency both oscillators were uncoupled. Handgrip and cold test failed to affect BP-SAS cardiac-respiratory coupling. We showed similar handgrip and cold test cardiac bispectral coupling for individual subjects. Further studies are required to establish whether the observed intersubject variability concerning the BP-SAS coupling at cardiac frequency has any potential clinical predictive value.

Influência do estilo de vida e IMC sobre variáveis hemodinâmicas de escolares / Influence of lifestyle and BMI on hemodynamic variables of schools

Introdução: O estilo de vida tem sofrido mudanças significativas por influência sociocultural, implicando em alterações das atividades habituais, como no nível de atividade física. Objetivo: O presente trabalho buscou analisar a influência do estilo de vida e Índice de Massa Corpórea (IMC) sobre variáveis hemodinâmicas de escolares. Materiais e métodos: Participaram 101 estudantes do ensino fundamental. O nível de atividade física foi avaliado por meio do Physical Activity Questionaire for Older Adolescents (PAQ-A) e foi realizada uma avaliação física (peso, altura, frequência cardíaca e pressão arterial). Resultados: Quanto ao estilo de vida, 63,4% foram considerados insuficientemente ativos (IA) e 36,6% suficientemente ativos (SA). Quanto ao IMC, 6,9% foram classificados como baixo-peso, 71,3% adequado e 21,8% sobrepeso. Os IA apresentaram aumento significativo (p=0,0088) na frequência cardíaca quando comparados aos SA. Os alunos baixo-peso e sobrepeso apresentaram aumento da FC (p=0,0012) quando comparados aos alunos com peso adequado. Conclusão: Nossos achados apontam que o estilo de vida saudável aliado ao peso adequado é capaz de contribuir na prevenção de alterações hemodinâmicas.

Introduction: The lifestyle has undergone significant changes due to sociocultural influence, implying changes in usual activities, such as in the level of physical activity. Objective: This study aimed to analyze the influence of lifestyle and Body Mass Index (BMI) on hemodynamic variables of schoolchildren. Materials and methods: A total of 101 elementary school students participated. The physical activity level was assessed through the Physical Activity Questionnaire for Older Adolescents (PAQ-A) and a physical assessment (weight, height, heart rate and blood pressure) was performed. Results: Regarding lifestyle, 63.4% were considered insufficiently active (AI) and 36.6% sufficiently active (SA). Regarding BMI, 6.9% were classified as lowweight, 71.3% adequate and 21.8% overweight. AI had a significant increase (p = 0.0088) in heart rate when compared to SA. Lowweight and overweight students had an increase in HR (p = 0.0012) when compared to students with adequate weight. Conclusion: Our findings indicate that a healthy lifestyle combined with adequate weight may contribute to the prevention of hemodynamic changes.

Cardiac frequency and cutaneous microcirculation during and after exercising in the view of physical condition.

INTRODUCTION: In the field of cardiovascular diseases an ergometer test is a common diagnostical method in which a change in microcirculation can be reached. In this paper cardiac frequency and cutaneous microcirculation during and after exercising will be compared with each other. MATERIALS AND METHODS: The cutaneous microcirculation of  6 healthy volunteers (2 females, 4 males) is measured. As an instrument the PeriFlux 5000 combined with a Laser-Doppler-Flow(LDF)-Probe (Perimed Instruments) is used. The cardiac frequency (CF) is measured by the POLAR T31 sensor and as an ergometer the ERGO-FIT ® 457 is used. RESULTS: The mean initial LDF (97,7±57,3 PU) decreases at the beginning (64,5±21,7 PU), increases during theexercise, reaches its maximum (247,8±82,1 PU) after the end of the exercise and drops to lower values (256,4±69,5 PU)after a few minutes. Contrasting to the LDF the mean initial CF (86±22/min) increases at the beginning (97±9/min),furthermore during the whole exercise (103±9/min) and then falls after having finished the exercise (96±3/min).Furthermore, during regeneration, one can see the CF decreasing towards its initial value, while LDF reaches its maximum. CONCLUSION: In further studies, realized with volunteers with well-known levels of physical condition, a directconnection between cutaneous microcirculation and physical condition might be found.

Efeitos de um salgante isento de sódio sobre marcadores sanguíneos bioquímicos hepáticos, renais e cardíacos de ratos normo e hipertensos / Effects of a sodium-free salting agent on blood hepatic, renal and cardiac biochemical markers of normal and hypertensive rats

Introdução: A hipertensão arterial é um dos fatores de risco para doenças cardiovasculares, estando diretamente associada ao elevado consumo de sódio. Objetivo: Avaliar os níveis de marcadores de lesão hepática, renal e cardíaca em ratos hipertensos comparados aos seus controles normotensos, tratados com um salgante isento de sódio, água ou NaCl. Métodos: Ratos hipertensos (SHR) e seus controles normotensos (NWR) foram divididos em 3 grupos (n=7): G1 (água); G2 (solução aquosa contendo NaCl 70 mg/kg/dia); G3 (solução aquosa contendo salgante sem sódio 70 mg/kg/dia). Após 30 dias, o sangue dos animais foi processado. Resultados: Não houve diferença entre os níveis séricos de creatina quinase total, creatina quinase-MB, lactato desidrogenase, ácido úrico, aspartato aminotransferase e fosfatase alcalina tanto nos NWR como nos SHR tratados com NaCl ou Salgante. Houve diminuição da creatinina nos NWR e SHR tratados com NaCl e Salgante em relação aos controles (p<0,005). Conclusões: A suplementação diária com o Salgante e NaCl diminuiu os níveis séricos de creatinina nos grupos NWR e SHR. Contudo, não houve modificação nos níveis séricos de marcadores de lesão cardíaca e hepática. (AU)

Introduction: Hypertension is one of the risk factors for cardiovascular diseases, being directly associated with high consumption of sodium. Objective: To assess the levels of hepatic, renal and cardiac injury markers in hypertensive rats compared to their normotensive controls, treated with a salt free saline solution, water or NaCl. Methods: Hypertensive rats (SHR) and their normotensive controls (NWR) were divided into 3 groups (n = 7): G1 (water); G2 (aqueous solution containing NaCl 70 mg / kg / day); G3 (sodium salt-free aqueous solution 70 mg / kg / day). After 30 days, the animals' blood was processed. Results: There was no difference between serum levels of total creatine kinase, creatine kinase-MB, lactate dehydrogenase, uric acid, aspartate aminotransferase and alkaline phosphatase in both NWR and SHR1 treated NaCl or Salgante. There was a decrease in creatinine in NWR and SHR treated with NaCl and Salgante comparing to controls (p <0.005). Conclusions: Daily supplementation with sodium salt-free aqueous solution and NaCl decreases serum creatinine levels in NWR and SHR groups. However, there was no change in serum levels of cardiac and hepatic injury markers. (AU)

Wavelet transform analysis to assess oscillations in pial artery pulsation at the human cardiac frequency.

Pial artery adjustments to changes in blood pressure (BP) may last only seconds in humans. Using a novel method called near-infrared transillumination backscattering sounding (NIR-T/BSS) that allows for the non-invasive measurement of pial artery pulsation (cc-TQ) in humans, we aimed to assess the relationship between spontaneous oscillations in BP and cc-TQ at frequencies between 0.5 Hz and 5 Hz. We hypothesized that analysis of very short data segments would enable the estimation of changes in the cardiac contribution to the BP vs. cc-TQ relationship during very rapid pial artery adjustments to external stimuli. BP and pial artery oscillations during baseline (70s and 10s signals) and the response to maximal breath-hold apnea were studied in eighteen healthy subjects. The cc-TQ was measured using NIR-T/BSS; cerebral blood flow velocity, the pulsatility index and the resistive index were measured using Doppler ultrasound of the left internal carotid artery; heart rate and beat-to-beat systolic and diastolic blood pressure were recorded using a Finometer; end-tidal CO2 was measured using a medical gas analyzer. Wavelet transform analysis was used to assess the relationship between BP and cc-TQ oscillations. The recordings lasting 10s and representing 10 cycles with a frequency of ~1 Hz provided sufficient accuracy with respect to wavelet coherence and wavelet phase coherence values and yielded similar results to those obtained from approximately 70cycles (70s). A slight but significant decrease in wavelet coherence between augmented BP and cc-TQ oscillations was observed by the end of apnea. Wavelet transform analysis can be used to assess the relationship between BP and cc-TQ oscillations at cardiac frequency using signals intervals as short as 10s. Apnea slightly decreases the contribution of cardiac activity to BP and cc-TQ oscillations.

Características e resultados do teste de inclinação na população sintomática: [revisão] / Characteristcs and results of tilt table testing in symptomatic population: [review] / Características y resultados de la prueba de inclinación en la población sintomática: [revisión]

Síncope é um sintoma de prevalência significativa na população geral e possui prognóstico variável de acordo com sua etiologia. O teste de inclinação ou Tilt-teste é um exame útil na investigação dos pacientes com Síncope, Hipotensão Postural e Disautonomia e trata-se de um exame já rotineiro em nosso meio. Objetivo: Analisar o índice de positividade do exame, além dos seus tipos de respostas mais comuns, e a necessidade do uso da sensibilização com dinitrato de isossorbida no auxílio do diagnóstico. Material e métodos: Entre o período de março de 2005 a junho de 2009, foram avaliados 348 pacientes submetidos ao Tilt-teste, dentre os quais, 244(70,1%) pacientes eram do sexo feminino com idade média de 36 anos. Resultados: O Tilt-teste foi negativo em 163(46,8%) pacientes. Nos exames positivos, o tipo mais comum de resposta foi a vasodepressora em 113(32,47%) pacientes, seguido pela resposta mista em 56(16,1%) pacientes e cardioninibiotória em 14(4%) pacientes. Dois pacientes apresentaram quadros de Disautonomia e Síndrome da Taquicardia Postural Ortostática (POTS). O tempo médio para positivação dos exames foi de 28 minutos após início da ortostase, sendo que, em 166(89,72%) pacientes, foi necessário uso de sensibilização com dinitrato de isossorbida por via sublingual. Conclusão: Na população estudada, observamos que o Tilt-teste foi positivo em 53,2% dos casos. Dentre esses pacientes, a forma mais comum de resposta da síncope neurocardiogênica foi a vasodepressora em 113 pacientes, sendo que o uso da sensibilização foi necessário em quase 90% dos pacientes na positivação dos exames.

Syncope is a symptom of significant prevalence in the general population and has changeable prognostic in accordance with its etiology. The inclination test or Tilt table test is a useful examination in the investigation of patients with syncope, postural hypotension and disautonomy and it is a routine examination already in our way. Objective: To analyze the positive rate of the exam, in addition to its most common types of response and the need of sensitization with isosorbide dinitrate to aid the diagnosis. Material and methods: 348 patients submitted to Tilt table test were evaluated between March of 2005 and June of 2009, 244 (70.1%) females at the mean age of 36 years. Results: The Tilt table test was negative in 163 (46.8%) patients. In the positive exams the most common type of response was the vasodepressor in 113 (32.47%) patients, followed by the mixed response in 56 (16.1%) patients and cardioinhibitory in 14 (4%) patients. Two patients had history of disautonomy and Postural Ortostatic Tachycardia Syndrome (POTS). The average time for positivation of the examinations was of 28 minutes after the beginning of the ortostasis, in 166 (89.72%) patients the use of sensitization with isosorbide dinitrate via sublingual was necessary. Conclusion: In the studied population weobserve that the Tilt table test was positive in 53,2% of the cases. Among these patients the most common response of neurocardiogenic syncope was the vasodepressor in 113 patients and the use of the sensitization was necessary in almost 90% of the patients in the positivation of the examinations.

Síncope es un síntoma de prevalencia significativa en la población general y tiene pronóstico variable de acuerdo con su etiología. La prueba de inclinación o Tilt-test es un examen útilen la investigación de los pacientes con Síncope, Hipotensión Postural y Disautonomia y ya se trata de un examen de rutina en nuestro medio. Objetivo: Analizar el índice de positividad del examen, además de sus tipos de respuestas más comunes, y la necesidad del uso de la sensibilización con dinitrato de isosorbida para ayudar el diagnóstico. Material y métodos: Entre el período de marzo de 2005 y junio de 2009, se evaluaron a 348 pacientes sometidos al Tilt-test, entre los cuales, 244 (70,1%) pacientes eran del sexo femenino con edad media de 36 años. Resultados: El Tilt-test fue negativo en 163 (46,8%) pacientes. En los exámenes positivos, el tipo más común de respuesta fue la vasodepresora en 113 (32,47%) pacientes, seguido de la respuesta mixta en 56 (16,1%) pacientes y cardioinhibitoria en 14 (4%) pacientes. Dos pacientes presentaron cuadros de Disautonomia y Síndrome de Taquicardia Postural Ortostática (POTS). El tiempo medio para positivación de losexámenes foi de 28 minutos tras el inicio de la ortostasis, siendo que, en 166 (89,72%) pacientes, fuenecesario el uso de sensibilización con dinitrato de isosorbida por vía sublingual. Conclusión: En la población estudiada, observamos que el Tilt-test fue positivo en el 53,2% de los casos. Entre dichos pacientes, la forma más común de respuesta del síncope neurocardiogénico fue la vasodepresora en 113 pacientes, siendo que el uso de la sensibilización fue necesario en casi el 90% de los pacientes en la positivación de los exámenes.

Ansiedade, medo e sinais vitais dos pacientes infantis / Anxiety, fear and vital signs of the child signs of the child patients

Este estudo o objetivo de determinar os sinais vitais dos pacientes infantis, especificamente, presão arterial e frequencia cardíaca antes, durante e após os procedimentos odontológicos, relacionando-os com ansiedade e medo, avaliados através do Venham Picture Test (teste VPT), realizado antes e após o atendimento. A amostra constou de 44 pacientes inscritos nas Clínicas de Odontopediatria da Universidade Federal de Pernambuco, no período de fevereiro a julho de 2008. O teste VPT foi associado com gênero, idade, história médica e odontológica das crianças. A anáise dos dados foi realizada pelo Test de Friedman e a associação do test VPT com as demais variáveis foi estudada, estimulando-se odds-ratio e intervalos de confiança de 95%. Os resultados não revelaram associações estatisticamente significantes entre sinais vitais e reações emocionais. Porém o teste VPT mostrou-se um instrumento de avaliação de ansiedade infantil eficiente, especialmente em idade pré-escolar, das quais a maioria apresentou ansiedade. Quando associado à história odontológica, mostrou que criança com experiência negativa em consultas odontológicas são mais ansiosas, mas não apresentou relação com história médica e gênero. A adoção do teste VPT pelos odontopediatras parece ser uma sugestão plausível para avaliar a ansiedade e o medo nos pacientes, especialmente em idade pré-escolar.

This study has the objective to determinate the vital signs of the childlike patients, specifically, blood pressure and cardiac frequency, before, during and after the dental proceeding, and connected them with the anxiety and the fear valued through the Venham Picture Test (VPT) carried out before and after the proceedings. The sample was composed by 44 patients registered in the Clinics of Odontopediatric of the Federal University of Pernambuco, in the period of February to July 2008. The VPT test was also connected with genre, age, medical and odontologic history of the children. Data analysis was performed by Friedman test and the test VPT association with the other variables were studied with an estimated odds-ratio and confidence intervals of 95%. The result did not reveal statistically significant associations between the vital signs and the emotional reactions. However, the test VPT was shown a very efficient instrument of evaluation of anxiety in children, especially in pré-school age, which majority presented anxiety. When associated with odontologic history, it showed that the children with negative experience in odontologic consultations are more anxious, however doesn 't shown relations with the medical history and with the genre. The adoption of the VPT test for the odontopediatrics it seems to be a credible suggestion to value the anxiety and the fear on his patients, especially in pre-school age.

Comportamento da frequência cardíaca durante uma sessão de surfe / Heart rate behavior during a surfing session

O objetivo do estudo foi determinar o comportamento da frequência cardíaca durante uma sessão de surfe, a média total, a média dentro de cada fase do padrão de movimento e o porcentual da frequência cardíaca máxima. Fizeram parte da amostra sete homens com respectivas médias de massa corporal, estatura, idade e tempo de prática de 77,57 ± 3,21 (kg), 176,3 ± 8,14 (cm), 24,71 ± 4,82 (anos) e 9,86 ± 3,02 (anos). A frequência cardíaca foi monitorizada com utilização de um frequencímetro marca Polar, modelo S610i em intervalos de cinco segundos durante uma sessão de vinte minutos de surfe, realizada na praia do Rosa – Imbituba (SC), filmada com uma câmera de vídeo marca JVC, modelo GR-SXM289UB. Foram avaliados os porcentuais de tempo e frequência cardíaca média em cada uma das fases do padrão de movimento pré-estabelecido, e média total. A frequência cardíaca média da sessão foi 143,94 ± 13,18 (bpm), e as médias da frequência cardíaca durante as fases de movimento onda, parado, remando e outros movimentos foram, respectivamente de 157,10 ± 14,81, 127,58 ± 8,86, 151,93 ± 10,73 e 141,08 ± 18,34 (bpm). A média da frequência cardíaca da sessão correspondeu a 78,91% da frequência cardíaca máxima dos participantes. A intensidade de uma sessão de surfe pode ser considerada moderada e a fase onda do padrão de movimento no surfe possui a média de frequência cardíaca mais elevada. Palavras chave: surfe, frequência cardíaca e exercício intermitente.

The objective of the study was determine the behavior of the cardiac frequency during a session of surfi ng, on average total, on average inside each phase of the standard of movement and the percentage of the maximum cardiac frequency. They were part of the sample seven men with respective medium of corporal mass, stature, age and time of practice of 77.57 ± 3.21 (kg), 176.3 ± 8.14 (cm), 24.71 ± 4.82 (years) and 9.86 ± 3.02 (years). The cardiac frequency was monitored with utilization of a frequencímetro marks Polar, model S610i in breaks of fi ve seconds during a session of twenty minutes of surfi ng, carried out in the beach of the Rose – Imbituba (SC), it fi lmed with a camera of video marks JVC, model GR-SXM289UB. They were evaluated the percentages of time and medium cardiac frequency in each one of the phases of the standard of movement pre-established, and medium total. The medium cardiac frequency of the session was 143.94 ± 13.18 (bpm), and the medium of the cardiac frequency during the wave movement phases, standstill, rowing and others movements were, respectively of 157.10 ± 14.81, 127.58 ± 8.86, 151.93 ± 10.73 and 141.08 ± 18.34 (bpm). On average of the cardiac frequency of the session corresponded to 78.91% of the cardiac frequency maxim of the participants. The intensity of a session of surfi ng can be considered moderated and the phase wave of the standard of movement in the surfi ng possessed on average of cardiac frequency more elevated.