American horse racing is very diffent to most other countries. Very speed orientated. This comes from racing predominantely on the dirt tracks instead of on turf. Horses resent getting shit thrown up at them so the pattern of racing on dirt is different. In the US it is normal for horses to run incredible early sectionals and then almost walk to the line. In most countries the fastest sectionals are normally the last part of the race.
This is one reason the Triple Crown is so hard to complete. Most th'breds can sustain this pattern of racing for about 2mins, the Belmont at 12furlongs takes 2.24plus. The early pace in the Belmont is usually about the same as for the other 2 legs. Given this pattern of racing more often than not the horses have slowed more than 2secs a furlong over the last 1-2 furlongs and pretty much anything can happen. Often a less talented horse that has been ridden less aggressively will run over the better horses. Of course every now and then a Secretariat arrives on the scene and just keeps going. nb.Secretariat won the triple crown in the 70s he won the Belmont in record time by a taggering 31 lengths.
In most countries the first few furlongs would be a relaxed jostle for positions and the horses would accelerate in the last 3-4 furlongs and sprint the last 1-2 as in middle distance running events. Therefore in most parts of the world horses are trained for this pattern of racing.
In Australia our richest race is the Melbourne Cup over 3200m/16f. usually takes 3.15-20.
The Japenese came out 2years back and finished 1st and 2d.
Their training patterns involved large amounts of slow work with occassional very hard efforts. The volume of slow work was much greater than is normal for Australian trainers. Also I've noted the Europeans/Brits use more slow work and often use hill reps in place of fast track work.
The great Aussie m/distance horse Northerly was trained off much more slow/steady pace training than is typical. He would do lap after lap of steady work on the heavy sand.
He was renowned for his fighting finishes and toughness.
The great jumps trainer Jim Houlahan used to give his horses huge volumes of slow xc work as a base for the long hurdle/steeplchase races. This is now much the norm for the Australian jumps trainers. Of course they add in faster gallops, hill work, jumps schooling and usually a shorter flat race or two in their build up.
One difference between man and horse is that the horse comes to peak fitness much more quickly so requires much less time and volume than we do.