D-ribose, a natural occurring pentose carbohydrate, has repeatedly shown to enhance high-energy phosphates and improve function following ischemia, states of congestive heart failure, and recently in subjects with lung disease. An initial preliminary, open label pilot study demonstrated a positive benefit of D-ribose in "Baby-Boomer" subjects aged 50 to 65 years old complaining of persistent fatigue. The objective of this study will build on the previously collected data to evaluate oral D-ribose vs. dextrose (administered as a supplement) in relatively healthy, yet fatigued subjects with a goal of improving their state of fatigue.