Every time your colt’s heart beats during a morning gallop, how far does he travel?
If it’s 6 feet, you are never going to win a race with him, time to cut bait and save yourself the aggravation. If it’s 14 feet, don’t think of selling because you are going to be fishing at the stakes level.
We call this the Thoroughbred Efficiency Score in feet per beat: (Distance in feet)/(time in sec)/(avg. heart rate) x 60
(For example: 660feet/22/165 = 10.91) - 6 feet up to 14 feet is the range of possible outcomes
70-80% of all energy in a TB race is aerobic in nature, meaning with oxygen, even during 6F ‘sprints’. This is your cruising speed as is very predictive of your ultimate success, or failure.
Think of a human miler who races for approx 4 min vs our Derby colt running for 2 min.
If you take 2 humans who can each run a 4 min/mile, the winner will be the one in practice who can accomplish more quarter mile intervals in :50sec – as in a competitive race he will have more physiological strength to count on in trying to hit 3:55. Because of the nature of equine conditioning this is not safe to do, so we need an onboard HR/GPS monitor to gauge what is going on internally, without running him to death via repeated intervals.
All horses can gallop a furlong in 15-25 seconds, but the amount of aerobic fuel required to do so differs greatly. And when you stretch them out to a race of 6-10F in 11-12 second splits – the one who is more metabolically efficient will excel as he will go the furthest before fatigue sets in.
Please look for me this September at the Pedigree and Genetics Symposium in Lexington where I will be giving a presentation on the intersection of genetic expression and real world measures of metabolic efficiency. The genesis for this idea comes from The Genetics of the Horse by Ann Bowling and Anatoly Ruvinsky, most notably pages 458-460: