The purpose of the present study was to analyze the effects of two pre-exercise energy bars on glycemic response and 10 km running performance in recreationally active college-aged females. Fifteen females (age: 20 ± 1 years; BMI: 21 ± 1.9 kg/m²; body fat: 20 ± 3.5%) were assigned to consume one of the energy bars on two separate occasions. Each testing session included an 8 h overnight fast, 24 h dietary recall, consumption of an energy bar (Power Bar: low glycemic index (GI); high glycemic load (GL); Snickers Bar: low GI; low GL) within 30 min of the time trial, 10 km run, fasting, pre 10 km and post 10 km blood glucose measurements. Heart rate (HR), RPE, time, perceived recovery (PR), gut fullness and bar preference was recorded for each trial. Repeated measures ANOVA indicated a significant difference (p=0.007) in blood glucose levels between the two energy bars (Power Bar: 3.7 ± 0.6, 5.5 ± 1.1, 5.6 ± 1.2 mmol/L; Snickers Bar: 3.8 ± 0.4, 4.5 ± 0.4, 5.3 ± 0.9 mmol/L, for fasting, pre 10 km and post 10 km, respectively). There was no significant difference (p=0.65) in average 10 km time (52.25 ± 6.4 and 52.00 ± 6.7 min between Power Bar and Snickers Bar, respectively), first and second 5 km time (p=0.85), post 10 km HR (p=0.99) and RPE (p=0.80). Although, there was a significant difference in metabolic response between the two preexercise energy bars lower GL bar did not provide an ergogenic effect over high GL energy bar under the conditions of the present study
