If deadly serious and you consider fitness to be a prime factor you then need to track a horse from the beginning of a campaign via trackwork and barrier trials. Of course you are limited somewhat by the amount of information available but there is still plenty to occupy yourself with.

There are a few little clues (which I do not intend to share) that can be picked up by analysing trackwork times and barier trial results.

Then again, as Chief suggests, there is the "trained eye". Look for some of these when next at the races:

To begin with, look at the horse's conformation. Does he have low soles that may be prone to stone bruising? Is he a touch weak behind the saddle, lacking rounding and engaging muscles?

Look at the abdomen for signs of a heave line during respiration.

Muscular definition, especially on the crest, shoulders, loins, hindquarters, forearm and thigh.

When you see a horse sweating, don't worry if the sweat is clear.

And, no, I won't be providing night classes in equine anatomy.

Privateer