Horse speed has not improve over the past 50 years but humans did drastically. Why?

This can easily be fixed by letting the horses race without jockeys on them.

Imagine if human runners had to carry monkeys as jockeys, and then you took the monkeys off. All the records gone, bam.

If you can train a dog to run like hell around a track by itself, I see no reason why a horse can't be trained to do it too.

It's because no horses have the dedication to run double threshold

Could it be because the price of a horse is so high that if you get one you have more interest of sticking to a tried method proven to work as opposed to innovate as the cost of failure is too high

Since there has been dramatic improvements in times across all level’s including HS, the advances are most likely due to mechanics, such as tracks and shoes. HS kids aren’t taking PEDs at the wholesale level, yet times are improving dramatically

If you were having your ass whipped while you were racing you would run to your limit, too.

Knowing nothing about horse training.

Does it actually make a difference? Humans, of course, react very strongly to training, but what about horses?

I know knowing about 'lion training' either, but I imagine if you could get a lion in the gym lifting weights it would have very little, if any, effect on their muscle mass. A lion that gets out of shape isn't long for this world--or at least a male lion isn't long for leading his pride--so they probably don't.

Human population has gone up, and more people have committed their time and energy to sports. Horse populations have gone down, and fewer people are committing to working with horses.

Athletics for a long time was just something you did in a club during your school years and then you stopped, it wasn't a job and people didn't commit to it during their professional work career. But people were making money from horse racing a long time ago and already reached their peak years of people who owned horses and worked with them.

Considering that XC speed ratings are somewhat based on the Beyer Speed Figures used in horse racing, I bet Bill Meylan could address this question better than just about anybody here if he was interested.

Horses are very fragile and extremely expensive. It doesn't take much to seriously injure a horse by pushing it too hard. Horses are not made for sprinting all out. Their lower limbs are very fragile. So, the limits of what a horse can do in training are pretty well defined and well established over many years of trial and error. The other thing is that horses are animals. You can't get a horse to lift weights, do pilates/yoga or plyometrics. A horse can run at different speeds for different lengths of time and that is about it. People have been able to improve because they have been able to improve upon training techniques year after year. Yes, people have been doping and equipment has improved. But there is a huge difference in the quality of training today versus the 1970s. I ran jr high track and XC under a coach who was a Div I runner at UGA and made NCAA champs in 5k. She was about as good as you would find back then. The training kids do today is on a completely different level.

It’s quite simple. The average horse - horses are flight animals - is already closer to their maximum than the average human. Humans untrained aren’t so great at running; humans with training can be or at least they’ll get closer to their maximum potential.

But keep in mind that horse racing isn’t just a matter of speed. It’s multi factorial, including things like if the horse is willing to run in front of other horses or if the horse will keep trying when he’s getting mud kicked up in his face. A horse can have all the speed in the world and not be interested in racing.

There are outliers like Secretariat, Spectacular Bid and the blazing fast Dr. Fager.

Thoroughbreds are inbred like mad and maybe are getting worse because of it. They should breed in some other horses for fresh blood.

The literal reason for their top performance is their non-fresh blood, i.e. the extra blood cells they store in their spleen. To get away from the saber tooth cat or whatever, their spleen would release the extra blood. The horses with the worst spleen would get eaten, but even the ones with the best spleen probably had some health effects from this process. The respiratory bleeding IIRC is possibly an effect.

They are capable of running themselves to death.

Thinking about this a bit further lead me to wonder why you chose fifty years as the era to compare. Does your question mean that say, a hundred years ago horses did get faster and then stopped doing it fifty years ago?

Thoroughbred horse racing has been international and popular since 19th Century. T&F has become international and mildly popular since 20th Century. Horses peaked 50 years ago, 1/2 mile to 1 1/2 mile. Humans, 60m to 1500m seemed to have peaked about 7 years ago. With fast shoes and fast tracks, more guys are racing sub-1:47 800m more than ever, but no one has raced sub-1:42 800m in over 4 years; with fast shoes and fast tracks, more gals are racing sub-2:02 800m more than ever but no woman has raced sub-1:55 800m in over 7 years.

Humans have more room for improvement. Horses have reached the full potential.

Humans haven't been used to run and pull carts for hundreds of years - horses have. Running has only been popular at an international scale like it is now for maybe 60-70 years? I think humans are just now capable of tapping into our running fitness potential, unlike horses.

Fifty years ago (Secretariat, 1973) is about as fast as horses ever got. I'm not the op, but that's the first thing I thought of when I saw your question. Seems reasonable.

No one is even close here. The reason that horse racing hasn’t changed is that the engine that generates tremendous power in horse racing can’t really be trained. Horses can be doped with good results, but training isn’t going to affect the fact that their internal organs act as a bellows to completely empty the lungs when they are at full gallop. Secretariat was a once in a century talent AND he didn’t get hurt.

The training stress - adaptation cycle that is responsible for human gains is not applicable to horses. Train too much and you ruin/kill the horses for racing.

To the OP, why would any animal get significantly faster over what is a nanosecond of evolutionary time??

Your not even close. No different for humans.