Effects of statins on fat oxidation improvements after aerobic exercise training.

BACKGROUND: Statin blunts cardiorespiratory fitness improvements after exercise training and may affect fat oxidation adaptations to training.

METHODS: One hundred and six metabolic syndrome individuals either chronically medicated with statins (i.e., STATIN group; n = 46) or statin naïve (i.e., CONTROL group; n = 60) completed a 16-week supervised high-intensity interval training (HIIT) program. Maximal rates of oxygen consumption (V̇O2MAX), fat oxidation (FOMAX), and the shape of the workload-fat oxidation curve were assessed before and 48 h after training in an overnight fasted state.

RESULTS: Starting from a similar value at baseline, both groups increased V̇O2MAX after training, but the increase was larger in the CONTROL than in the STATIN group (19.4% vs. 12.6%; P = 0.013). Before training, FOMAX in the STATIN group was lower (0.19 ± 0.08 vs. 0.23 ± 0.07 g·min-1; P = 0.023) and took place at a lower workload (33 ± 21 vs. 37 ± 19 W; P = 0.015) than in CONTROL. After training, FOMAX improved similarly in both groups (0.06 ± 0.08; 95% CI, 0.03 to 0.08 g·min-1 and 0.05 ± 0.09; 95% CI, 0.03 to 0.07 g·min-1, for STATIN and CONTROL respectively; P < 0.001). Still, after training, FOMAX occurred at a 28% lower workload in the STATIN group (38 ± 26 vs. 53 ± 32 W, P = 0.048).V̇O2 -workload slope decreased after training in both groups (both P < 0.001) along with reductions in the respiratory exchange ratio - workload slope. Fat oxidation increased at all workloads after training regardless of the use of statins.

CONCLUSION: Long-term statin treatment is associated with blunted exercise fat oxidation before exercise training. However, statin use does not blunt the improvements in exercise fat oxidation (FOMAX) derived from intense aerobic exercise training. This finding should encourage statin users to exercise-train to benefit from increased fat oxidation once their fitness level improves.