Effect of 4h Preexercise High Carbohydrate and High Fat Meal Ingestion on Endurance Performance and Metabolism

Abstract

The effect of a single high carbohydrate meal (HCM) and high fat meal (HFM) given 4 h before cycling exercises was determined for performance and metabolism. On the morning of the day of the trial, 10 endurance-trained collegiate males consumed either a single HCM (4669 kj; 79% CHO, 10% F and 11% P) or HFM (4711 kj; 30% CHO, 61% F and 9% P) as a 4 h preexercise meal. The intensity of exercise required was 65% of the maximal oxygen consumption (VO2max) for the first 120 min of exercise, followed by an increased dose of 80% VO2max. Endurance capacity did not differ between the HCM (128 +/- 3 min [SEM]) and HFM (122 +/- 3 min) trials. There was no significant difference in blood glucose levels in the HCM and HFM trials. A significantly higher (p < 0.01) serum insulin level in the HCM trials over the HFM trials was only observed at the start of exercise. Blood lactate levels (< 2.6 mM) during cycling remained below the anaerobic threshold. Respiratory exchange ratio in the HCM trials was significantly higher (p < 0.05 or p < 0.01) than that in HFM trials during the first 40 min of exercise. This was accompanied by significantly lower (p < 0.05 or p < 0.01) levels in serum free fatty acid and beta-HOB for the HCM trial. There was no significant difference between both diet regimens as to heart rate, oxygen consumption and perceived exertion during exercise. These results suggest that a single HCM and HFM given 4 h before exercise influences fuel utilization in the initial stages of prolonged cycling, but these meals may have little effect on endurance capacity.

Effect of Fat and CHO Meals on Intermittent Exercise in Soccer Players

“…However, again insulin was not analysed postprandially so similar caveats to the present investigations may be warranted. This contrasts the observations from previous research [ 21 ] that noted significant elevations in insulin concentrations after a HCM relative to [ 11 ] . A possible explanation for the performance impairments with these studies is the high fat diets they utilise may result in a reduction in muscle and liver glycogen stores prior to exercise.…”

“…An increase in β-hydroxybutyrate concentration was also found throughout exercise following ingestion of the HFM, which may refl ect stimulation of hepatic ketosis due to greater levels of fat metabolism. This result refl ects similar observations in cycling [ 21 ] . The presence of elevated concentrations of fat metabolites following the consumption of a HFM relative to the HCM may be attributed to the greater availability of fat following the HFM.…”

“…However, present data indicates an exaggerated increase in fat oxidation with the consumption of a HFM. Furthermore, fat metabolite responses are in accordance with previous research; with signifi cant increases in FA [ 21 , 22 , 28 ] , glycerol [ 21 , 22 ] and β-hydroxybutyrate [ 21 ] after the ingestion of a HFM and during subsequent exercise performance. The observations of FA are consistent with others who report increases over the 90 min of match play, irrespective of the preexercise nutritional strategies employed [ 15 ] .…”

“…Ten male recreational soccer players all of whom trained twice a week and played a weekly competitive match were recruited for the study (Age: 24.3 ± 2.3 yrs [range: [21][22][23][24][25][26] …”

The Effect of the Timing of Meal Intake on Energy Metabolism during Moderate Exercise

“…Fats are supplied by meals, and also by adipose tissues, but CHO must be acquired from meals before exercise because little is stored as glycogen in the liver or muscle tissue. Previous studies have been conducted on the ergogenic effects of CHO feeding before exercise (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). It was reported that CHO solution (such as glucose and maltodextrin) feeding before exercise can improve exercise performance through enhanced endurance exercise capacity (2,4,5,10).…”