I find extremes very interesting when they occur in nature. Often there is a good reason behind some observable anomaly. Viewing the above graphs seems to suggest a major decrease in speed records in our modern times and there ought to be a good reason for this! Do not our experts tout this new century as being the best ever for technology as related to equine health, track surfaces, tack, nutrition, etc.? Do we not find more horses racing in more and richer events than ever before? Are our breeding farms ever more elaborate and steeped in proven breeding theories? Even more perplexing, we observe with this decrease in record performances, there was an extreme increase in numbers of individual horses racing and number of racing events carded. The question is why? What makes speed in our Thoroughbred and why does this speed seem to have lapsed in the last few decades? Some of the common variables for our sport may be seen in the breed itself. Representative individuals of the breed are constantly evolving. Training methodology may have changed. Also, riding styles, track surfaces, number of racing dates, advanced tack design, new medications, number of individuals competing, etc. may all have their influence on speed records. Then there is the view that the biologic horse can only go so fast and no faster. Have we hit this proverbial brick wall in performance increases? Another view is the "freak" theory. That those horses that can produce speed records are freaks of nature and should not be used as a gauge for breed improvement at any time in Thoroughbred history. There are, of course, truths to all of these points and fallacies, but I tend to dismiss most of them as not really worthy when given close consideration. It is so easy to lose sight of the forest by viewing only the closest trees. You will have to find your own big picture and look beyond what may appear obvious.
Depending on who you ask, you will get a different opinion. It is only human nature for the specialist to view his discipline as the primary influence on his world in general. For example, the trainer often views the conditioning program as paramount. The veterinarian will view the therapeutics sphere of racing as most important. The farrier may view improved racing plates as the key. The trackman will view his carefully manicured racing surface as the cause. These self-interests will go on and on. All of these biases aside, I find Dr. Robert Cook's views in his Specifications for Speed in the Racehorse, generally refreshing and enlightening though one must take into account that he is a veterinarian throat/windpipe man. What he has to say is food for thought and should not be lightly dismissed.
He points out a very vital fact about the Thoroughbred race horse. What is the one thing absolutely required in immediate time for a horse to compete successfully against others? Air, oxygen to be more exact. A horse can run without being fed that day, he can run without water, he can run without human intervention of any kind, but he absolutely must have oxygen to move at that precise moment. Respiration is vital for life and competition. You may have a superior race horse in all other respects, but you remove his capability to efficiently provide his body access to oxygen with corresponding exhalation of wastes and he is doomed. We have all seen the perfect individuals that are conformation and pedigree exquisite but could not beat a fat man! We have also seen horses prepared immaculately by trainer and groom and rode to perfection without achieving much success at all on the track. One thing is for sure, we have never seen a racehorse with an impaired breathing problem, ever, do well in competition. Always look to the variables of crucial importance! Only there within, may lay the truth in analyzing complex systems governed by limiting processes.
To make sense out of such a complex sport of many variables, a perspective of priorities is a must. Without the presence of oxygen, muscles will not move, the mind will not respond, and the body will not compete. We all know how quickly an inserted sponge can affect performance in the tampered racehorse! Stride length and stride rate is often pointed to as making speed. However, Dr. Cook points out that "…speed is probably governed more by the ability to breathe than by the ability to stride." Rate and depth of breathing in the racehorse is intimately linked to stride length and stride rate of that same horse. And Dr. Cook goes on to write that the most important factor limiting respiration is resistance to airflow found mostly in the throat and voice box. A running horse takes one stride for every breath. Breathing seems to govern striding in the racehorse. As Dr. Cook writes: "The deeper the breath, the longer the stride. The classic racehorses have the longest stride. As length of stride seems to be governed by ease with which a horse can breathe, rather than by the length of leg, the easy breathers are the best racehorses."
So, what comes in second on our priorities list to breathing? Personally, I think it is still something that must be intimately linked to breathing efficiency and that would be conditioning. It is the training program that hones the breathing apparatus of the racehorse for maximum efficiency. You can run a horse with flawless breathing conformation, but if he is not conditioned to compete most efficiently at the distance he is entered, he will fail. It doesn't matter if he has the biggest natural heart, the most prolific pedigree, the genetically superior natural speed, the best jock, etc-he will most likely fail and the longer the race the more certain that failure will be. Air flow and the training program designed to condition respiration under stress are the two requisites of priority for speed in the Thoroughbred. All others are dwarfed by their importance. The trends shown in the above graphs probably are influenced by those two variables more than any other, a healthy airflow path and a properly conditioned animal. I feel that our modern trends to under-train our horses, particularly during the initial foundation stages of a racehorse's program, in the last 20 years or so is a major detriment to obtaining top performance from our modern horses and the lowering of our current records. I do not feel that the American Thoroughbred has hit a physiological barrier. Our breed has the capability of sustaining a high rate of speed, longer, over a racing event than ever before. Conditioning is a key.