Well, D-ribose is necessary for ATP, which is an energy form for muscle and heart tissue. it does support cardiovascular metoabolism, and seems to help with enhancing cardiac energy levels. So it really is an great supplement to be taking when doing high intensity workouts, and will really help with energy levels and recovery from these workouts. However, I wouldn't necessarily recommend using it to replace carbs either. But
D-Ribose is definitely something that would be great to add in this case (keeping some carbs in the diet as well).