Because paradoxical sleep deprivation (PSD) induces a catabolic hormone profile, we sought to evaluate the morphology of the tibialis anterior (TA) muscle and testosterone and corticosterone levels of paradoxical sleep-deprived rats. Three study groups of rats were established: the first group was sleep deprived for 96 h; the second group was also sleep deprived for 96 h, but then returned to their home-cage and allowed to sleep for the next 96 h; and the third group was the control group, with a normal sleep cycle. PSD reduced the weight and fiber cross-sectional area of the TA muscle. Moreover, PSD enhanced plasma corticosterone and reduced serum testosterone levels. The 96 h of sleep after PSD was sufficient to restore partially the morphology of TA, while hormones returned to basal levels. PSD induces hormonal alterations that may mediate muscle atrophy. Copyright © 2011 Wiley Periodicals, Inc.