Increased blood cholesterol after a high saturated fat diet is prevented by aerobic exercise training

A high saturated fatty acids diet (HSFAD) deteriorates metabolic and cardiovascular health while aerobic training improves them. The aim of this study was to investigate in physically inactive and overweight people if 2 weeks of HSFAD leads to hyperlipemia or insulin resistance and if concurrent aerobic exercise training counteracts those effects. Fourteen overweight (body mass index, 27.5 ± 0.6 kg·m(-2)), healthy, young individuals (aged 24.8 ± 1.8 years) were randomly assigned to a diet (D) or a diet plus exercise (D + E) group. During 14 consecutive days both groups increased dietary saturated fatty acids from 31 ± 10 to 52 ± 14 g·day(-1) (p < 0.001) while maintaining total fat intake. Concurrent to the diet, the D + E group underwent 11 cycle-ergometer sessions of 55 min at 60% peak oxygen uptake (V˙O(2peak)). Before and after intervention, insulin sensitivity and body composition were estimated, and blood lipids, resting blood pressure, and VO(2peak) were measured. Body weight and composition, plasma free fatty acids composition and concentration, and insulin sensitivity remained unchanged in both groups. However, post-intervention total cholesterol (T(C)) and low-density lipoprotein cholesterol (LDL-C) increased above pre-intervention values in the D group (147 ± 8 to 161 ± 9 mg·dL(-1), p = 0.018 and 71 ± 10 to 82 ± 10 mg·dL(-1), p = 0.034, respectively). In contrast, in the D + E group, T(C) and LDL-C remained unchanged (153 ± 20 to 157 ± 24 mg·dL(-1) and 71 ± 21 to 70 ± 25 mg·dL(-1)). Additionally, the D + E group lowered systolic blood pressure (6 ± 2 mm Hg, p = 0.029) and increased VO(2peak) (6 ± 2 mL·kg(-1)·min(-1), p = 0.020). Increases in T(C) and LDL-C concentration induced by 14 days of HSFAD can be prevented by concurrent aerobic exercise training, which, in addition, improves cardiorespiratory fitness.