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High rates of exogenous carbohydrate oxidation from a mixture of glucose and fructose ingested during prolonged cycling exercise.
Jentjens, Roy L. P. G.; Jeukendrup, Asker E. *
[Article] British Journal of Nutrition. 93(4):485-492, April 2005.

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A recent study from our laboratory has shown that a mixture of glucose and fructose ingested at a rate of 1[middle dot]8 g/min leads to peak oxidation rates of approximately 1[middle dot]3 g/min and results in approximately 55 % higher exogenous carbohydrate (CHO) oxidation rates compared with the ingestion of an isocaloric amount of glucose. The aim of the present study was to investigate whether a mixture of glucose and fructose when ingested at a high rate (2[middle dot]4 g/min) would lead to even higher exogenous CHO oxidation rates (>1[middle dot]3 g/min). Eight trained male cyclists (VO2max: 68 /-1 ml/kg per min) cycled on three different occasions for 150 min at 50 % of maximal power output (60 /-1 % VO2max) and consumed either water (WAT) or a CHO solution providing 1[middle dot]2 g/min glucose (GLU) or 1[middle dot]2 g/min glucose 1[middle dot]2 g/min fructose (GLU FRUC). Peak exogenous CHO oxidation rates were higher (P <0[middle dot]01) in the GLU FRUC trial compared with the GLU trial (1[middle dot]75 (SE 0[middle dot]11) and 1[middle dot]06 (SE 0[middle dot]05) g/min, respectively). Furthermore, exogenous CHO oxidation rates during the last 90 min of exercise were approximately 50 % higher (P <0[middle dot]05) in GLU FRUC compared with GLU (1[middle dot]49 (SE 0[middle dot]08) and 0[middle dot]99 (SE 0[middle dot]06) g/min, respectively). The results demonstrate that when a mixture of glucose and fructose is ingested at high rates (2[middle dot]4 g/min) during 150 min of cycling exercise, exogenous CHO oxidation rates reach peak values of approximately 1[middle dot]75 g/min.