Current recommendations for carbohydrate (CHO) intake in the field for all modes of endurance exercise are largely based on laboratory studies that measured oxidation of ingested CHO. However, the majority of these laboratory studies utilized cycling as the mode of exercise and it is not known whether these results can be extrapolated to running. PURPOSE:: To investigate exogenous CHO oxidation from a CHO drink during moderate intensity running (RUN) compared to cycling (CYCLE). METHODS:: Eight athletes with comparable CYCLE and RUN training backgrounds (37+/-7 yr; 75+/-7 kg; 1.77+/-0.05 m; VO2max CYCLE: 63+/-3 mL/kg/min; VO2max RUN: 65+/-4 mL/kg/min) performed four exercise trials in random order. The trials consisted of either running or cycling at ~60% of the exercise specific VO2max for 120 min while receiving either a CHO drink (2:1 glucose:fructose blend; 1.5 g/min) or a similar volume of plain water (WAT; 675 mL/h). RESULTS:: The set workload elicited similar relative exercise intensities of 59.7+/-2.0 % and 59.2+/-1.9 % VO2max for RUN and CYCLE, respectively. Peak and average exogenous CHO oxidation rates were not significantly different between RUN and CYCLE trials and showed a similar time course (Peak at 120 min: 1.25+/-0.10 g/min vs. 1.19+/-0.08 g/min, respectively; p=0.13; Average over final h: 1.14+/-0.10 and 1.11+/-0.11 g/min, respectively; p=0.94). Furthermore, total fat oxidation rates were higher during RUN compared CYCLE. The difference was significant with ingestion of WAT (p=0.02) and failed to reach statistical significance with CHO (p=0.09). CONCLUSION:: This study demonstrates that exogenous CHO oxidation rates are similar between prolonged running and cycling at a similar relative moderate intensity. These data suggest that previous exogenous CHO oxidation results from cycling studies can be extrapolated to running.