"The Derby is a day away. It's Friday. Time for me to use what I considered a small secret weapon with this particular horse. I had done it with him in nearly every race of his career, but had kept it secret from the press.
A day prior to each of his races, instead of just galloping him for exercise, I would have the rider gallop about a mile and then quicken the pace to do the last half in 52 and change - a light breeze.
I kept that a secret race after race because if he would have thrown in a dull effort, the critics would have said it was because he'd been breezed the day before.
But, Unbridled could do a half in 52 and change and not really be extending himself. Instead of squeezing a drop from the lemon, I was merely adding to the potency of the contents."
-from Traits of a Winner, by Carl A. Nafzger
Very smart fellow, he may not know why it worked, but it did and he kept it quiet to avoid the media onslaught of second guessers.
Now, if you are reading this you likely don't have Unbridled in your barn and a half in 52 the day before a race will be way too much. Try a quarter instead, or 3F 2 days out, etc.
The key is to empty the spleen and fill it with new, oxygen rich blood cells just prior to raceday.
Many, many such 'uncharted' works are taking place out there every day - not too mention routine gallops ending in a few 13sec furlongs. None of this makes the DRF, so don't read the form and think you know everything that goes on behind the scenes to condition a horse.