Plasma fat concentration increases in visceral fat obese men during high-intensity endurance exercise

The purpose of this study was to investigate differences in fat metabolism between visceral fat obese (VF-Ob) and abdominal subcutaneous obese (SF-Ob) men during "high-intensity endurance exercise". Fourteen obese (body mass index >25 kg/m(2)) men were classified into two groups according to visceral fat area using computed tomography; i.e., VF-Ob (n = 7; mean age, 52.0 ± 2.5 year) and SF-Ob (n = 7; mean age, 57.3 ± 2.8 year) groups. Plasma fat concentration and fat oxidation were measured at rest and during 60-min high-intensity (70% of peak oxygen uptake) stationary cycling exercise. Plasma concentrations of free fatty acid and glycerol were significantly higher (P ≤ 0.05) in VF-Ob men compared with SF-Ob men during endurance exercise. However, no significant difference was found in fat oxidation between VF-Ob and SF-Ob men (697 ± 135 and 661 ± 96 kJ/h, respectively) during high-intensity endurance exercise. These results suggest that obesity phenotype affects plasma fat concentration even during high-intensity exercise. It is likely that plasma fat concentrations in visceral fat obese men during high-intensity endurance exercise are more increased compared with during moderate-intensity endurance exercise. Despite the difference in plasma fat concentration, total fat oxidation was similar in the two obese phenotypes.: