Data/hora: 01/06/2024 06:02:45

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Training-related changes in the R-R interval at the onset of passive movements in humans	
Autores: 	Vianna,L.C.; Ricardo,D.R.; Araújo,C.G.S.	
Data: 	2008-09-01	
Ano: 	2008	
Palavras-chave: 	Mechanoreceptors; Vagus nerve; Muscle stretching exercises; R-R interval.	
Resumo: 	The aim of the present study was to determine whether training-related alterations in muscle mechanoreflex activation affect cardiac vagal withdrawal at the onset of exercise. Eighteen male volunteers divided into 9 controls (26 ± 1.9 years) and 9 racket players (25 ± 1.9 years) performed 10 s of voluntary and passive movement characterized by the wrist flexion of their dominant and non-dominant limbs. The respiratory cycle was divided into four phases and the phase 4 R-R interval was measured before and immediately following the initiation of either voluntary or passive movement. At the onset of voluntary exercise, the decrease in R-R interval was similar between dominant and non-dominant forearms in both controls (166 ± 20 vs 180 ± 34 ms, respectively; P &gt; 0.05) and racket players (202 ± 29 vs 201 ± 31 ms, respectively; P &gt; 0.05). Following passive movement, the non-dominant forearm of racket players elicited greater changes than the dominant forearm (129 ± 30 vs 77 ± 17 ms; P &lt; 0.05), as well as both the dominant (54 ± 20 ms; P &lt; 0.05) and non-dominant (59 ± 14 ms; P &lt; 0.05) forearms of control subjects. In contrast, changes in R-R interval elicited by the racket players' dominant forearm were similar to that observed in the control group, indicating that changes in R-R interval at the onset of passive exercise were not attenuated in the dominant forearm of racket players. In summary, cardiac vagal withdrawal induced by muscle mechanoreflex stimulation is well-maintained, despite long-term exposure to training.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000900014	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X2008000900014	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.41 n.9 2008	
Fonte: 	info:eu-repo/semantics/openAccess