In a double-blind crossover study, 26 healthy subjects were given 10 g daily of D-ribose or 10 g daily of dextrose (which served as the control) for two days, followed by another three days of treatment that was paired with high intensity exercise (60 minutes of cycling). When subjects took D-ribose, the mean and peak power output was significantly higher from day one to three, compared to the control group. The D-ribose group also had a significantly lower rate of perceived exertion and lower levels of creatine kinase.
Seifert JG, Brumet A, St Cyr JA. (2017). The influence of D-ribose ingestion and fitness level on performance and recovery. J Int Soc Sports Nutr. 14: 47