Injuries that lead to a forced layoff of activity often happen in one's lifetime. Research has also shown that during this period of forced rest that one not only loses aerobic fitness, but muscle mass is also lost due to inactivity or being confined to a cast, as in the example of a broken leg.
Research out of Katholieke Universiteit Leuven, Leuven, Belgium, shows that creatine taken in doses ranging from 20 grams per day down to 5 grams per day during a 10-week rehabilitation program compared to a placebo aided in faster recovery of muscle mass and fitness. In the study, subjects' legs were casted for 2 weeks. Thereafter, the subjects participated in a knee-extension rehabilitation program. Half the subjects where given creatine, and half were given a placebo during the 10 weeks of rehab. Immobilization of 2 weeks decreased quadriceps muscle size by about 10% and maximal knee extension strength by about 25 % by the same magnitude in both groups. During rehabilitation, thigh size and maximal knee extension strength recovered at a significantly faster rate in the creatine supplemented group than in the placebo group.
The authors concluded that creatine supplementation stimulates muscle growth and strength during rehabilitative strength training.