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Journal of Nutrition and Metabolism
Volume 2011 (2011), Article ID 172853, 6 pages
http://dx.doi.org/10.1155/2011/172853
Research Article

Effects of Mixed Isoenergetic Meals on Fat and Carbohydrate Metabolism during Exercise in Older Men

1Department of Sports and Exercise Physiology, Sports Science Research Centre, Ministry of Science, Research and Technology, 1587958711 Tehran, Iran
2Research Institute for Sport & Exercise Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK
3Department of Sports and Exercise Physiology, Faculty of Sports Sciences, Shahid Beheshti University, Tehran, Iran

Received 1 December 2010; Accepted 14 April 2011

Academic Editor: R. A. Fielding

Copyright © 2011 Minoo Bassami et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The present study was designed to investigate the effects of four different meals on fat and CHO metabolism during subsequent exercise in elderly males. Eight healthy males (age: 63.3 ± 5.2 years) reported to the physiology laboratory on four separate occasions, each of which was allocated for the performance of a 30-minute exercise on a cycle ergometer at 60% ̇ V O 2 m a x after having normal (N), high fat (HF), high carbohydrate high glycaemic index (HGI) and high carbohydrate low glycaemic index (LGI) meals. Fat oxidation during exercise after the meals ( H F = 0 . 2 6 ± 0 . 0 4  g/min; N = 0 . 2 1 ± 0 . 0 4  g/min; H G I = 0 . 2 2 ± 0 . 0 3  g/min; L G I = 0 . 1 9 ± 0 . 0 3  g/min) was not significant ( 𝑃 > . 0 5 ), and neither were the rates of carbohydrate oxidation ( N = 1 . 7 9 ± 0 . 2 8 , H F = 1 . 5 8 ± 0 . 2 2 , H G I = 1 . 6 8 ± 0 . 2 2 , and L G I = 1 . 7 7 ± 0 . 2 1  g/m). NEFA concentration increased after HF ( 𝑃 < . 0 5 ) but decreased after HGI and LGI ( 𝑃 < . 0 5 ). Glucose concentration decreased as a result of exercise after HF, and LGI ( 𝑃 < . 0 5 ) whereas insulin concentration decreased significantly during exercise after N, HF, and HGI ( 𝑃 < . 0 5 ). It can be concluded that, in elderly males, feeding isoenergetic meals containing different proportions of carbohydrate and fat do not significantly alter oxidation of fat and CHO during exercise in spite of changes in some circulating metabolites.