I have a vague idea that this has been discussed before, but, is there any chance that when we do a Training Summary, Natural Energy can be added to the information displayed for each horse?
Feel free to submit it as a feature request on the bug system. Only problem I see is that physical energy is quite easy to tell, mental energy not so much. (At least not to such a fine degree, it would probably just be “Good” until it’s “Exhausted”.)
You can use the jockeys to tell in workouts, and the rewrite of that will let you pick what you want to learn about, so you could run a workout with a jockey to find out.