They’re off and…what’s pacing?

When it comes to promoting Harness Racing and second careers for Standardbreds there is one question that is guaranteed to come up regularly, without a doubt:

What is pacing?

This is usually followed by a series of questions about why the horses are ‘forced’ to do that, how they can be ‘cured’ of it, if they’re even capable of anything other than pacing, what the straps around their legs are for, or a personal favourite, “but how did you teach it to trot?”

I’m going to try and answer all of those below, and hopefully break some stereotypes and misconceptions about pacing, retraining Standardbreds, and harness racing in the process.

Simply put, trotting is a two beated gait where the legs move in diagonal pairs whereas pacing is a two beated gait where the legs move in lateral pairs. For example:

Trotting – The left front leg moves in unison with the right hind leg. These legs are diagonally across the body from each other. Accordingly, the right front leg moves with the left hind leg. This creates two diagonal pairs of legs that move alternatively to create the two beated gait we know as trotting.

Pacing – The left front leg moves in unison with the left hind leg. These legs are on the same side of the body. Accordingly, the right front leg moves with the right hind leg. This creates two lateral pairs of legs that move alternatively to create the two beated gait we know as pacing.

In between each beat in both trotting and pacing there is what’s called a moment of suspension where all four legs are off the ground with one pair of legs reaching forward across the ground, and the other pair of legs extended backwards having just propelled the horse forward.

Now, when it comes to Standardbreds generally there are two varieties, those that race while trotting, and those that race while pacing. There are exceptions to this rule, as there are horses that have raced doing both, but they are uncommon. Occasionally, due to gene selection and the inheritance of certain genes when breeding, you will see a pacing Standardbred show up in a trotting bloodline, and occasionally you will see a trotting Standardbred show up in a pacing bloodline. But we’ll get into that later.

With that said, Standardbreds who pace CAN ALSO trot. The ability to pace is an additional gait in horses, not a replacement gait. That is to say, pacing DOES NOT REPLACE trotting. It merely gives the horses another option when it comes to movement.

The Science behind Pacing:

This is all determined by the presence of a mutation of the DMRT3 gene.  The DMRT3 gene is present in all mammals and dictates locomotion, or the ability to move, in all mammalian creatures. Mice have it, people have it, and horses have it. A mutation of this gene is what allows the horses to pace, and also to maintain either pacing or trotting at a very high speed. Horse breeds that do not possess this mutation would simply break into a canter or gallop to maintain higher speeds. The presence of additional genetic modifiers determine which gait the horse prefers. This is based on a study by Andersson et al., “Mutations in DMRT3 affect locomotion in horses and spinal circuit function in mice”where they looked into which genes allow the horses pace as well as to do so at high speeds.

 “In contrast to the pattern in Icelandic horses, where homozygosity for DMRT3_Ser301STOP was associated with the ability to pace, both Standardbred pacers and trotters are homozygous for the mutation. Thus, the mutation may promote the ability to trot or pace at high speed and genetic modifiers determine the gait to which the horse is best suited.” Andersson et al.

This study also showed the presence of the DMRT3 gene resulted in increased flexion, and extension of the limbs creating a greater stride length and enhanced propulsion.
In short, the ability to pace and to do so at high speeds, is genetically predetermined and a part of the horse’s DNA.

The Purpose of Hopples:

There are a number of misconceptions about harness racing that frequently appear in popular media. One of the these is that the hopples worn by harness racing horses are there to ‘force’ the horse into the gait by ‘tying their legs together with improvised shackles’.  This is, unfortunately, perpetuated by a lack of understanding of genetics, as well as a lack of understanding of the purpose and function of hopples.

Hopples are worn to help balance the pace in a harness racing horse, especially around turns. They aid the horse by encouraging regularity in the gait, however they do not keep the horse from walking or galloping while they are being worn. (Much to their owners dismay – some Standardbreds are remarkably good at galloping while wearing hopples.) However, some Standardbreds are naturally balanced enough to race without hopples. Major Hottie, a Canadian horse who most recently raced and stood stud in Alberta, is the current World Record Holder for free-legged pacers (with a lifetime mark of 1:48.3). Free-legged means he raced without the use of hopples. He was a pacer and maintained this gait throughout the race, however once he was done racing he would turn around and trot back to the barn.

Here is the news coverage from Standardbred Canada from Hottie’s world record setting race. The image at the top of the article clearly shows Major Hottie not wearing any hopples of any kind while pacing. Furthermore, a number of Standardbreds can be seen regularly pacing while turned out in the field, being ridden, or while quietly jogging – all without hopples.

Trotting bred Standardbreds can also wear hopples specifically designed for trotting while racing, however these are not as common. Both varieties of hopples serve the same purpose and help stabilize the pairs of legs while traveling at high speeds.

Retraining the Pacer to Canter:

Due to the nature of harness racing (aka if you canter you are disqualified), Standardbreds that previously raced, or have gone through race training, typically have to go through a period of retraining.  This is because they have been taught (as necessary for their sport) that pacing is VERY desirable, and cantering is very NOT desirable. Likewise, when they get confused or flustered it is very easy for them to revert back or ‘guess’ that pacing is the answer because up until now, pacing has always been the answer. With patience and the right amount of positive encouragement, they can learn that you are instead asking for the canter.


Some things I’ve found to be helpful while developing the canter are:

1) Thinking of the canter as a gait change, and change in the way of moving, but not necessarily as a speed change. For non-gaited horses, faster means canter. For retired harness racing horses, faster means pacing. (or simply more trot for the trotters.)

2) Small jumps, cavalettis, and placing poles. These exercises can help reassure the canter and give the horse the sensation of a regular canter rhythm. It can also encourage the horse to lift their spine and engage their core muscles which makes carrying the canter easier.

3) Finding a long stretch of ground, longer than found in the typical arena, like a field, and letting the horse have some time to ‘practice’ cantering without having to worry about turning, or avoiding obstacles.

4) Praise. Praise the horses excessively for every canter effort made. Standardbreds are known for having an incredible work ethic, take advantage of that and use their enthusiasm to build on success. It’s all about taking the little moments and extending them.

In conclusion:

The ability to pace, and to maintain the trot and/or pace at high speeds is determined by genetics and is therefore a natural thing for horses possessing the mutation of the DMRT3 gene to do. Horses that are capable of pacing are also capable of walking, trotting, cantering, and galloping with some horses showing a strong preference for pacing over ‘regular horse’ gaits. All Standardbreds are capable of the canter but some of them, especially those with lengthy harness racing careers, require extra assistance and patience to learn how to balance in the canter, and to build the muscles necessary for doing so.

If you have any questions, or suggestions for future topics you'd like to see me cover feel free to message me on Facebook, or send me an email,!

5 thoughts on “They’re off and…what’s pacing?

  1. Lynda says:

    That was very informative, many yrs ago in the 80s, my cousin Nd i helped on stables were three sets of relations all trained harness racers, one family preferred trotters to pacers, we had great times jogging in the sulky round the oval track, we would go to york or to Musselburgh, etc and we would aslo ride out the horses hacking, one of the names i remember was a stallion calles repeat performance, owned by jd maw Nd driven by Gary maw, ws had great times i prefer the standard bred thT trots to pace, also i visit my cousin in malta, trotters are very popular in marsa its there biggest sport

  2. Amy B says:

    Great article! I have an unraced pacer and my ex’s gelding is actually True Story (was the World Record holder for fastest double gaited. I believe he is now 2nd). I ridden both pacers who have raced and not raced as well as trotters and I have ALWAYS found that pacers are SO much easier to get to canter! I suspect it’s because the leg movement of pace and canter is so similar. If you want to see my mare in action, I have a YouTube Channel called “Standard Equestrian”. She’s super bouncy and has a difficult trot, but her canter is lovely and smooth. I think standies are the best all around horse! I’m not being biased at all! LOL They are great in the show ring, playing around on the farm, hack with little to no spook, great jumpers, hard workers and dedicated to their humans who love them! Thanks for writing this article! It’s great!

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