Performance Effects of Carbohydrate Ingestion Between Bouts of Intense Aerobic Interval Exercise

This study tested whether CHO intake during a 2-h rest between exercise bouts improved performance in the subsequent bout. In a randomized, single-blinded, crossover design, 10 recreationally-active participants (23 ± 4 yr, 70.8 ± 6.6 kg, VO :47.0 ± 5.4 mL O ·min ·kg body mass ) arrived at the lab post-prandial and completed 2 exercise bouts separated by 2-h rest. Bouts included 5 x 4-min intervals at ~80% VO separated by 2-min at ~40% VO and ended with an endurance trial (ET) to voluntary exhaustion at ~90% VO . During intervals 1 and 4 in each bout expired gases were collected and O deficit was estimated. Immediately following bout-1, either a CHO (1.2 g CHO·kg body mass ) or placebo (PL) solution was consumed. ET duration decreased in bout-2 vs. 1 in both conditions (P