(-)-Epicatechin maintains endurance training adaptation in mice after 14 days of detraining

The purpose of this study was to determine whether (-)-epicatechin (mainly found in cocoa) could attenuate detraining effects in the hindlimb muscles of mice. Thirty-two male mice were randomized into 4 groups: control, trained, trained with 14 d of detraining and vehicle (DT-14-W), and trained with 14 d of detraining and (-)-epicatechin [DT-14-(-)-Epi]. DT-14-(-)-Epi received (-)-epicatechin (1.0 mg/kg2X/d), whereas water was given to the DT-14-W group. The latter 3 groups performed 5 wk of endurance training 5X/wk. Hindlimb muscles were harvested, and Western blots, as well as enzyme analyses, were performed. Training significantly increased capillary-to-fiber ratio (approximate to 78.8%), cytochrome-c oxidase (approximate to 35%), and activity (approximate to 144%) compared to controls. These adaptations returned to control levels for the DT-14-W group, whereas the DT-14-(-)-Epi group was able to maintain capillary-to-fiber ratio (approximate to 44%), CcO protein expression (approximate to 45%), and activity (approximate to 108%) above control levels. In addition, the increase in capillarity was related to decreased protein expression of thrombospondin-1, an antiangiogenic regulator. Furthermore, there were no significant differences in endurance capacity between the trained and DT-14-(-)-Epi groups. Our data suggest that (-)-epicatechin may be a suitable compound to maintain exercise-induced improved capillarity and mitochondrial capacity, even when exercise regimens are discontinued.-Huttemann, M., Lee, I., Malek, M. H. (-)-Epicatechin maintains endurance training adaptation in mice after 14 d of detraining. FASEB J. 26, 1413-1422 (2012). www.fasebj.org