Blood was allowed to clot at room temperature for 20 min and

centrifuged at 1500 × g for 10 min. The serum layer was removed and frozen at -70°C in multiple aliquots for later analysis. All variables were analyzed in duplicates. Plasma glucose concentration was determined spectrophotometrically (Hitachi UV 2001) with commercially available kits (Spinreact, Santa Coloma, Spain). β-Endorphin and insulin were assayed by radioimmunoassay method. Blood lactate concentration was determined spectrophotometrically (Dr Lange LP 20, Berlin, Germany). Haematocrit was measured by microcentrifugation see more and haemoglobin was measured using a kit from Spinreact (Santa Coloma, Spain). Post exercise plasma volume changes were computed on the basis of haematocrit and haemoglobin as previously described [30]. CV for glucose, insulin, β-endorphin and lactate were 5.3%, 4.9%, 4.8% and 2.1%, respectively. Dietary analysis To control for the effect of previous diet on the outcome measures of the study and establish that participants had similar levels of macronutrient ABT-888 concentration intake under the three conditions, they were asked to record their diet for three days preceding each trial and repeat this diet before the second and third exercise condition. Each subject had been provided with a written set of guidelines for monitoring dietary consumption and

a record sheet for recording food intake. Diet records were analyzed using the nutritional analysis system Science Fit Diet 200A (Sciencefit, Greece) and the results

of the analysis are presented in Table 1. Table 1 3-day dietary analysis recall (mean ± SD)   Control LGI HGI Energy (kcal) 3559 ± 177 3627 ± 153 3721 ± 393 Carbohydrates (% energy) 51.1 ± 1.3 51.8 ± 1.1 52.4 ± 1.3 Fat (% energy) 33.3 ± 1.4 PFKL 32.1 ± 1.1 31.6 ± 2.0 Protein (% energy) 15.6 ± 1.0 16.1 ± 1.6 16.0 ± 1.1 No significant differences were detected in any variable between control group, low glycemic index (LGI) group and high glycemic index (HGI) group. Statistical analyses The distribution of all dependent variables was examined by Shapiro-Wilk test and was found not to differ significantly from normal. Data are presented as mean ± SEM. Two-way ANOVA (trial × time) with repeated measurements on both factors were used to analyze the assessed parameters. If a significant interaction was obtained, pairwise comparisons were performed through simple contrasts and simple main effects analysis. One way ANOVA was used to analyze time to exhaustion, carbohydrate and fat oxidation rates. Results Exercise performance The average exercise intensity during the 1-h submaximal cycling for the control, LGI, and HGI trials were 64.9 ± 2.4%, 64.7 ± 1.9% and 65.0 ± 2.1% of VO2max, respectively and was not different between trials. Individual responses and mean values of time to exhaustion of the three trials after the 1-h cycling are presented in Figure 1A and 1B, respectively.