10 km TIME TRIAL PERFORMANCE IMPROVES FOL- LOWING THE CO-INGESTION OF A CAFFEINE AND CARBOHYDRATE SOLUTION

Previous research has reported that endurance perfor-mance is enhanced when 6 mg/kg BM caffeine is ingested either 1 h before exercise or in combination with a 6 % car-bohydrate solution during exercise (Cox et al, 2002) and the mechanism for this effect may be enhanced carbohy-drate oxidation rates when caffeine is ingested in combina-tion with a carbohydrate solution (Yeo et al, 2005). How-ever, there is limited information with regards to whether this ergogenic effect is also observed during running. Six recreationally active males (stature 179.8 +/- 9.1 cm; body mass 73.5 +/- 6.1 kg and VO2 max 62.1 +/- 2.9 ml/kg/min) gave their written informed consent to participate in this study, which had University of Essex ethical approval. Par-ticipants undertook 2 trials, and during each trial they con-sumed 5 ml/kg body mass (BM) of a 6.4 % carbohydrate-electrolyte beverage in addition to either 6 mg/kg BM of caf-feine (CHO-CAFF) or a placebo capsule (CHO) one hour before the start of exercise. During exercise, they ingested 2 ml/kg BM of the same beverage at 15 and 30 min. The ex-ercise protocol consisted of running on a motorised tread-mill (HP Quasar, Nussdorf, Germany) for 30 minutes at 70 % VO2 max, followed by a 10 km time trial. The or-der of the trials were randomly assigned, counterbalanced, and were separated by 7 days. Faster 10 km time trial per-formances were recorded in CHO-CAFF (47.0 +/- 13.1 vs. 48.8 +/- 13.7 min; t =3.09, P<0.05). Rating of perceived ex-ertion (Borg, 1998) was also lower in CHO-CAFF after 1