Meal frequency of pre-exercise carbohydrate feedings.
This study compared the effect of single and multiple carbohydrate feedings before exercise on biochemical and physiological responses during exercise. Eight males performed 3 runs for 1 h at 70 % VO(2max) after consuming a meal containing 2.5 g carbohydrate per kg body mass in a single dose 3 h before exercise (SF), the same meal in 5 equal doses at 3, 2.5, 2, 1.5, and 1 h before exercise (MF), or a liquid placebo 3 h before exercise (P). RER and carbohydrate oxidation rates were higher in SF and MF compared to P trials, but there was no difference between SF and MF trials. Pre-exercise insulin was 2.0- and 3.4- fold higher in SF and MF, respectively, compared to P, and 1.7-fold higher in MF compared to SF. Glycerol and NEFA were higher in P compared to SF and MF trials before and at the end of exercise. In conclusion, a carbohydrate meal containing 2.5 g . kg(-1) ingested in doses over 3 h before running produced higher hyperinsulinemia pre-exercise than that produced when the meal was consumed in a single dose. Nevertheless, estimated carbohydrate utilization and adipose tissue lipolysis during exercise after multiple feedings seemed to be as high as after a single feeding.
Chryssanthopoulos
C
C
Physical Education and Sports Science, University of Athens, Athens, Greece. chryssan@phed.uoa.gr
Petridou
A
A
Maridaki
M
M
Mougios
V
V
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005227:Fatty Acids / Q000097:blood; D005247:Feeding Behavior / Q000502:physiology*; D005990:Glycerol / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D008066:Lipolysis / Q000502:physiology; D008297:Male; D005082:Physical Exertion / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D005227:Fatty Acids; D007328:Insulin; D019344:Lactic Acid; D005990:Glycerol