Data/hora: 07/06/2024 07:58:59

Provedor de dados: 	56	
País: 	Brazil	
Título: 	Effect of carbohydrate availability on time to exhaustion in exercise performed at two different intensities	
Autores: 	Lima-Silva,A.E.; De-Oliveira,F.R.; Nakamura,F.Y.; Gevaerd,M.S.	
Data: 	2009-05-01	
Ano: 	2009	
Palavras-chave: 	Time to exhaustion; Muscle glycogen; Metabolism; Lactate thresholds.	
Resumo: 	This study examined the effects of pre-exercise carbohydrate availability on the time to exhaustion for moderate and heavy exercise. Seven men participated in a randomized order in two diet and exercise regimens each lasting 3 days with a 1-week interval for washout. The tests were performed at 50% of the difference between the first (LT1) and second (LT2) lactate breakpoint for moderate exercise (below LT2) and at 25% of the difference between the maximal load and LT2 for heavy exercise (above LT2) until exhaustion. Forty-eight hours before each experimental session, subjects performed a 90-min cycling exercise followed by 5-min rest periods and a subsequent 1-min cycling bout at 125% VO2max/1-min rest periods until exhaustion to deplete muscle glycogen. A diet providing 10% (CHOlow) or 65% (CHOmod) energy as carbohydrates was consumed for 2 days until the day of the experimental test. In the exercise below LT2, time to exhaustion did not differ between the CHOmod and the CHOlow diets (57.22 ± 24.24 vs 57.16 ± 25.24 min). In the exercise above LT2, time to exhaustion decreased significantly from 23.16 ± 8.76 min on the CHOmod diet to 18.30 ± 5.86 min on the CHOlow diet (P &lt; 0.05). The rate of carbohydrate oxidation, respiratory exchange ratio and blood lactate concentration were reduced for CHOlow only during exercise above LT2. These results suggest that muscle glycogen depletion followed by a period of a low carbohydrate diet impairs high-intensity exercise performance.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009000500002	
Editor: 	Associação Brasileira de Divulgação Científica	
Relação: 	10.1590/S0100-879X2009000500002	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Medical and Biological Research  v.42 n.5 2009	
Fonte: 	info:eu-repo/semantics/openAccess