Ritmo circadiano da forca muscular isocinética e fadiga isométrica
Data
2008
Autores
Araujo, Leana Goncalves 
Orientadores
Mello, Marco Tulio de
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Introdução: As capacidades biomotoras: força, velocidade, potência e resistência
muscular estão presentes em nossas atividades de vida diária (AVDs) e em muitas
modalidades esportivas. Além disso, um objetivo do tratamento fisioterápico é
preservar ou recuperar estas capacidades biomotoras em pacientes com doenças
neuro-muscúlo-equeléticas, idosos e atletas pós-lesão. O conhecimento do horário
do dia em que o desempenho físico está maior nos permite elaborar programas de
reabilitação e de treinamento físico mais efetivos e compreender qual o horário do
dia nosso corpo está preparado para realizar certo tipo de tarefa, às vezes
fundamental para o desempenho no trabalho, AVDS, no esporte e em
tratamentos. A presença de ritmo circadiano da força e fadiga muscular foi
analisada em oito voluntários do gênero masculino (idade 27 ± 3,2 anos, 74,6 ±
5,33 Kg, 174,6 ± 6,3 cm, % gordura corporal 18 ± 6.67 e % massa magra de 82 ±
6.67). Material e Método: Após três sessões de familiarização, os sujeitos foram
testados por seis dias em seis horários diferentes: 02:00, 06:00, 10:00, 14:00,
18:00, 22:00 horas, uma vez por semana. O voluntário permaneceu por trinta
minutos de repouso em posição de decúbito dorsal e depois foi realizado o teste
de força muscular na seguinte ordem: teste isocinético à 60 /s, teste isocinético à
240 /s e teste isométrico até a exaustão com descanso passivo de 4 minutos entre
cada teste. Temperatura retal (T r), pico de torque (PT), trabalho máximo (Tr Mx) e
potência média (Pot Méd) dos músculos flexores (Flx) e extensores (Ext) do joelho
com amplitude de 0 a 90 no modo isocinético e resitência à fadiga (Res Fad) e
pico de torque (PT) na contração isométrica voluntária máxima (CIVM) de
extensão do joelho à 60 de flexão de joelho foram mensurados. Os parâmetros
subjetivos do humor e nível de alerta e sonolência também foram avaliados.
Resultados: A T r apresentou ritmo circadiano com acrofase Ö 17:48 horas,
Mesor Me 37 C e amplitude A 0.41 C. Ritmo circadiano à 60 /s no PT dos
extensores do joelho (Ö 17:18 horas, Me 221.1 N/m; A 12.0 N/m), Tr Mx dos
extensores do joelho (Ö 16:54 horas, Me 229.3 J; A 12.4 J), Tr Mx dos flexores do
joelho (Ö 15:36 horas, Me 143.9 J; A 8.6 J), Pot Méd dos flexores do joelho (Ö
15:06 horas, Me 92.0 W; A 5.2W) e efeito da hora do dia significante para todas as
variáveis, exceto para Pot Méd extensora. Na velocidade de 240 /s a amplitude do
ritmo foi diferente de 0 para PT dos extensores do joelho (Ö 17:06 horas, Me
151.6 N/m; A 3.7 N/m) e para o Tr Mx dos extensores (Ö 17:30 horas, Me 170.5
N/m; A 5.5 N/m). Efeito da hora do dia foi estatisticamente significante para todas
as variáveis com exceção da Pot Méd extensora e Pot Méd flexora do joelho à
240 /s (p>0.05). Conclusão: O presente estudo demonstrou ritmo circadiano em
alguns índices do desempenho muscular. O efeito da hora do dia foi mais
pronunciado em baixa velocidade do movimento e para músculos extensores do
joelho. Tempo de resistência à fadiga não foi influenciado pela hora do dia. Estes
resultados sugerem que o controle do ritmo da força muscular tenha origem
multifatorial (fatores periféricos e centrais) e é influenciado pela temperatura
corporal, aspectos subjetivos, metabolismo e características individuais dos
sujeitos.
Introduction: The presence of a circadian rhythm of the maximum isometric torque and muscle were analyzed in eight male volunteers (age 27 ± 3,2 years, 74,6 ± 5,33 Kg, 174,6 ± 6,3 cm, % core fat 18 ± 6.67 and % thin mass 82 ± 6.67). Methods: After three familiarization sections, the volunteers were tested for six days in six different times: 02:00, 06:00, 10:00, 14:00, 18:00, 22:00 hours, once a week. Rectal temperature (T r), peak torque (PT), maximal work (Tr Mx) and median power (Pot Méd) of knee extensors and flexors were measured on isokinetic concentric mode at the velocities 60 and 240°/s and maximal isometric voluntary contraction (MIVC) of the knee extensors until exhaustion (fatigue resistance - Res Fad and PT) at 60 of knee flexion. Subjective parameters of humor and alertness-sleepiness were also measured. The test were carried out with thirty minutes rest on decubitus position and followed by strength test. Additionally, 4 minutes rest in between each test were performade. Results: T r showed circadian rhythm with acrofase Ö 17:48 hours, Mesor Me 37 C and amplitude A 0.41 C. Circadian rhythm at 60 /s of knee extensors PT (Ö 17:18 hours, Me 221.1 N/m; A 12.0 N/m), knee extensors Tr Mx (Ö 16:54 hours, Me 229.3 J; A 12.4 J), knee flexors Tr Mx (Ö 15:36 hours, Me 143.9 J; A 8.6 J), knee flexors Pot Méd (Ö 15:06 hours, Me 92.0 W; A 5.2W) and effect of time of the day significance to every variables except extensor Pot Méd. At velocity of 240 /s the rhythm amplitude was different of 0 to knee extensor PT (Ö 17:06 hours, Me 151.6 N/m; A 3.7 N/m) and to knee extensor Tr Mx (Ö 17:30 horas, Me 170.5 N/m; A 5.5 N/m). Effect of time of the day to all of the other variables except knee extensor Pot Méd and flexor Pot Méd at 240 /s were observed. MIVC did not show significant circadian amplitude and either effect of time of the day on the two variables. Subjective parameters of humor and alertness and sleepiness did not show effect of time of the day (p>0.05). Conclusion: The present study showed a significant circadian rhythm in some muscle strength performance indices. The biggest effect of time of the day was at slow movement velocity and to knee extensors muscles. Time of fatigue resistance was not influenced by the time of the day. Those results suggests that the control of the muscle strength rhythm has multifactors origin (peripherical and central factors) and they are influenced by core temperature, subjective aspect such as motivation, humor, alertness sleepiness, metabolism and individual characteristics of the subjects, changing the response to exercise and performance during 24hours of the day
Introduction: The presence of a circadian rhythm of the maximum isometric torque and muscle were analyzed in eight male volunteers (age 27 ± 3,2 years, 74,6 ± 5,33 Kg, 174,6 ± 6,3 cm, % core fat 18 ± 6.67 and % thin mass 82 ± 6.67). Methods: After three familiarization sections, the volunteers were tested for six days in six different times: 02:00, 06:00, 10:00, 14:00, 18:00, 22:00 hours, once a week. Rectal temperature (T r), peak torque (PT), maximal work (Tr Mx) and median power (Pot Méd) of knee extensors and flexors were measured on isokinetic concentric mode at the velocities 60 and 240°/s and maximal isometric voluntary contraction (MIVC) of the knee extensors until exhaustion (fatigue resistance - Res Fad and PT) at 60 of knee flexion. Subjective parameters of humor and alertness-sleepiness were also measured. The test were carried out with thirty minutes rest on decubitus position and followed by strength test. Additionally, 4 minutes rest in between each test were performade. Results: T r showed circadian rhythm with acrofase Ö 17:48 hours, Mesor Me 37 C and amplitude A 0.41 C. Circadian rhythm at 60 /s of knee extensors PT (Ö 17:18 hours, Me 221.1 N/m; A 12.0 N/m), knee extensors Tr Mx (Ö 16:54 hours, Me 229.3 J; A 12.4 J), knee flexors Tr Mx (Ö 15:36 hours, Me 143.9 J; A 8.6 J), knee flexors Pot Méd (Ö 15:06 hours, Me 92.0 W; A 5.2W) and effect of time of the day significance to every variables except extensor Pot Méd. At velocity of 240 /s the rhythm amplitude was different of 0 to knee extensor PT (Ö 17:06 hours, Me 151.6 N/m; A 3.7 N/m) and to knee extensor Tr Mx (Ö 17:30 horas, Me 170.5 N/m; A 5.5 N/m). Effect of time of the day to all of the other variables except knee extensor Pot Méd and flexor Pot Méd at 240 /s were observed. MIVC did not show significant circadian amplitude and either effect of time of the day on the two variables. Subjective parameters of humor and alertness and sleepiness did not show effect of time of the day (p>0.05). Conclusion: The present study showed a significant circadian rhythm in some muscle strength performance indices. The biggest effect of time of the day was at slow movement velocity and to knee extensors muscles. Time of fatigue resistance was not influenced by the time of the day. Those results suggests that the control of the muscle strength rhythm has multifactors origin (peripherical and central factors) and they are influenced by core temperature, subjective aspect such as motivation, humor, alertness sleepiness, metabolism and individual characteristics of the subjects, changing the response to exercise and performance during 24hours of the day
Descrição
Citação
ARAUJO, Leana Goncalves. Ritmo circadiano da forca muscular isocinética e fadiga isométrica. 2008. 153f. Dissertação (Mestrado) - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, 2008.