Combined isometric, concentric, and eccentric resistance exercise prevents unloadinginduced muscle atrophy in rats

Combined isometric, concentric, and eccentric resistance exer-cise prevents unloading-induced muscle atrophy in rats. J Appl Physiol 103: 1644–1654, 2007. First published September 13, 2007; doi:10.1152/japplphysiol.00669.2007.—Previously, we re-ported that an isometric resistance training program that was effective in stimulating muscle hypertrophy in ambulatory rats could not completely prevent muscle atrophy during unloading (Haddad F, Adams GR, Bodell PW, Baldwin KM. J Appl Physiol 100: 433–441, 2006). These results indicated that preventing muscle atrophy does not appear to be simply a function of providing an anabolic stimulus. The present study was undertaken to determine if resistance training, with increased volume (3-s contractions) and incorporating both static and dynamic components, would be effective in preventing unloading-induced muscle atrophy. Rats were exposed to 5 days of muscle unloading via tail suspension. During that time one leg receive