Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-04-05T13:22:28Z No. of bitstreams: 1 Jos?? Morais Souto Filho - Disserta????o 2017.pdf: 2337613 bytes, checksum: d7cfa48405acb0642a0b292e8e7d8944 (MD5) / Made available in DSpace on 2017-04-05T13:22:28Z (GMT). No. of bitstreams: 1 Jos?? Morais Souto Filho - Disserta????o 2017.pdf: 2337613 bytes, checksum: d7cfa48405acb0642a0b292e8e7d8944 (MD5) Previous issue date: 2017-02-17 / Modern society has been increasingly exposed to daily stress situations. Neuroexcitatory, metabolic, cardiovascular and even inflammatory responses may become hyperreactive to these situations, increasing the chances of diverse physiological dysfunctions, especially cardiovascular ones. It has been shown that a single exercise session performed prior to stress situations may be useful in attenuating blood pressure hyperreactivity to stress. Among the methods applied to evaluate cardiovascular reactivity to stress, is the cold pressure test (CPT). However, heart rate variability (HRV) responses to CPT have been poorly investigated. Although there is evidence that a higher level of physical fitness is related to a lower reactivity to stress, the relationship between muscle strength levels and cardiovascular reactivity to CPT has not been investigated yet. The aim of this study was to investigate the autonomic and cardiovascular responses to CPT in individuals with different levels of manual grip strength. This is a study where the use of questionnaire techniques, anthropometric measurements, hemodynamic measurements, neuromuscular evaluation, cardiovascular and autonomic reactivity to an induced stress test were used. A total of 57 male subjects aged 18 to 30 years participated in the study. After this evaluation and general procedures, volunteers were divided into tertiles by their relative manual grip strength level. The lower strength group (BF) presented higher values of body mass, body mass index (BMI), body fat and waist-to-height ratio compared to the mean strength (MS) and high strength (HS) groups. Regarding the cardiovascular reactivity to CPT, the three groups presented similar variation of blood pressure (BP), with systolic blood pressure (SBP) increasing significantly during CPT and decreasing during recovery until the third minute. Mean arterial pressure (Dampney et al.) showed higher values during CPT and lower in the third minute of recovery, which was also lower than the resting values for the FB group. Autonomic reactivity, as measured by HRV, demonstrated a discrepant behavior between the groups. During the CPT, subjects with lower manual grip relative strength had an BP response similar to the medium and high manual grip relative strength groups, but with greater sympathetic activation. / A sociedade moderna tem sido cada vez mais exposta a situa????es de estresse di??rias. As respostas neuroexcitat??rias, metab??licas, cardiovasculares e mesmo inflamat??rias podem se tornar hiper-reativas a essas situa????es, aumentando as chances de disfun????es fisiol??gicas diversas, em especial cardiovasculares. Tem sido demonstrado que uma ??nica sess??o de exerc??cio realizada antes das situa????es de estresse pode ser ??til para atenuar a hiperreatividade da press??o arterial ao estresse. Entre os m??todos aplicados para avaliar a reatividade cardiovascular ao estresse, esta o cold pressor test (CPT). No entanto, as respostas da variabilidade da frequ??ncia card??aca (VFC) ao CPT t??m sido pouco investigadas. Embora existam evid??ncias de que um maior n??vel de aptid??o f??sica esteja relacionado a uma menor reatividade ao estresse, a rela????o entre os n??veis de for??a muscular e a reatividade cardiovascular ao CPT ainda n??o foi investigada. O estudo teve como objetivo investigar as respostas auton??micas e cardiovasculares ao CPT em indiv??duos com diferentes n??veis de for??a de preens??o manual. Trata-se de um estudo onde se utilizou de t??cnicas de aplica????o de question??rios, tomada de medidas antropom??tricas, hemodin??micas, avalia????o neuromuscular, reatividade cardiovascular e auton??mica a um teste de estresse induzido. Participaram do estudo 57 sujeitos do sexo masculino com idades entre 18 a 30 anos. Ap??s esta avalia????o e os procedimentos gerais, os volunt??rios foram divididos em tercis pelo seu n??vel de for??a relativa de preens??o manual. O grupo baixa for??a (FB) apresentou valores mais elevados de massa corporal, ??ndice de massa corporal (IMC), gordura corporal e rela????o cintura-estatura em compara????o com os grupos m??dia for??a (FM) e elevada for??a (FE). Quanto ?? reatividade cardiovascular ao CPT, os tr??s grupos apresentaram varia????o similar da press??o arterial (PA), com valores de press??o arterial sist??lica (PAS) aumentando significativamente durante o CPT e diminuindo durante a recupera????o at?? o terceiro minuto. A press??o arterial m??dia (PAM) demonstrou valores mais altos durante o CPT e inferior no terceiro minuto de recupera????o, o que tamb??m foi menor do que os valores de repouso para o grupo FB. A reatividade auton??mica, medida pela VFC, demonstrou um comportamento discrepante entre os grupos. Durante o CPT os indiv??duos com for??a relativa de preens??o manual inferior apresentaram resposta PA semelhantes aos grupos de for??a relativa de preens??o manual m??dia e alta, mas com maior ativa????o simp??tica.