Effects of oral creatine supplementation on maximal pedalling performance in older adults

This study was conducted to investigate the effects of giving short-term do ses of creatine by mouth to healthy older male subjects, taking into accoun t their training status. A group of 42 volunteers was divided into three: a sedentary group composed of elderly sedentary men (n = 14, mean age 70.1 ( SEM 1.2) years], a trained group composed of elderly trained cyclists [n=14 , mean age 66.4 (SEM 1.4) years] and a young group composed of young sedent ary men [n = 14, mean age 26.0 (SEM 1.2) years]. In each group, double-blin d randomization was carried out: one half was given creatine (3x5 gday(-1)) , and the other was given an iso-nitrogenated placebo (3x10 gday(-1)). Befo re and after the 5 days during which the supplements were given, all subjec ts performed five all-out 10-s sprints separated by 60-s intervals of passi ve recovery, seated on a cycle ergometer. Power output, work done and heart rate data were recorded during each sprint. The elderly and the young sede ntary subgroups given creatine showed significant (P<0.05) improvements in maximal power (+3.7% and +2.0%, respectively) (+4.1% and +5.1%, respectivel y) in the subsequent tests. In contrast, no significant change in pedalling performances was observed in the trained elderly subjects. The creatine di d not change the exercise and recovery heart rate profiles, in any group. O ur study suggested that creatine given by mouth increases the anaerobic pow er and work capacity of sedentary people of different ages during maximal p edalling tasks. However, the level of physical activity seems to be a deter minant of the ergogenic effect of creatine in older subjects.