(‐)‐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/kg 2×/d), whereas water was given to the DT‐14‐W group. The latter 3 groups performed 5 wk of endurance training 5×/wk. Hindlimb muscles were harvested, and Western blots, as well as enzyme analyses, were performed. Training significantly increased capillary‐to‐fiber ratio (ã 78.8%), cytochrome‐c oxidase (ã 35%), and activity (ã 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 (ã44%), CcO protein expression (ã45%), and activity (ã108%) 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.—Hüttemann, 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