top of page
  • Amanda Anderson

How is your horse going to develop over time?

One of the top concerns riders speak to me about when saddle shopping is their horse changing with work and their saddle not fitting in the long run.

The first thought I want to put into your head is this: Do you know ANYONE who hires a Personal Trainer - and sticks to an intense training program - go from a size 6 to a size 16 in clothes? No? Me either.

As you can see, its ALWAYS the reverse (cheating and/or metabolic issues not withstanding), even if the person wasn’t overweight to begin with. Which brings us to some of the more prevalent things I hear about horse development...

There are quite a few MYTHS about how a horse will change with work. The most common ones are the following:

1. Any type of work - be it Dressage, Eventing, Show Jumping, or Endurance - will change the horse’s body in the same way - specifically, the horse will “get bigger”, and build muscles like a body builder does.

2. The horse will “get wider” with work, and thus will need a wider tree width as he advances up the levels.

3. All horse breeds will develop the same way with the same type of work.

Now let’s discuss what REALLY HAPPENS when you take an average horse and put him into a training program. Horses absolutely do change - and like humans, they will build muscle with weight training and get leaner with cardio/high intensity interval training (HIIT) work.

How much your horse changes depends on the following:

> The type of work (Dressage versus Endurance).

> The intensity of the exercise program (training 5 days a week with a professional versus 1-2 lessons a week with an amateur rider).

> The duration of the activity (30 minute lesson versus 8 hour endurance ride).

> The proper diet, of course (But for simplicity, we are going to assume that everyone is eating correctly).

For the sake of this article, let’s say we have an “average” horse who is going to a professional to be trained for 6 months. Prior to this, the horse was only ridden lightly a couple times a week because his owner has kids and works a 9-5. How will this horse change with work?

The easiest way to make this content relatable to you is to compare the horse (a mammal) to a human (also a mammal), because our muscles respond and adapt to exercise in the same way.

What would this horse look like if he was a human? Well, if our fictional horse/human is considered to be “average”, this means he isn’t fat - but he isn’t skinny either - because he hasn’t been doing much exercise lately. He’s got some excess weight around the waist, and his muscles are a bit saggy. Basically, he’s got the awesome Dad Bod going on.

One day, our fictional horse/human decides to take up an active sport, joins a team, and starts playing this sport 4-5 times a week. What changes can we expect to see? Regardless of the sport our person has chosen to play, over the first 30-90 days, he will lose body fat and GET LEANER***.

***I think people, in general, equate leanness with less strength. It is true that a marathon runner is probably not going to be able to deadlift what a body builder can, but the body builder is not going to be able to run long distances like the marathon runner. People have different types of strengths, and you can be quite strong without looking like Conan the Barbarian. (My mother is proof of that.)

However, what happens to his body after the initial 30-90 days depends solely on the type of sport/exercise our person chooses to play: AEROBIC or ANAEROBIC.

AEROBIC = Cardio/HIIT based activities. If you do this type of exercise, you will get LEANER.

ANAEROBIC = Body building/weight lifting activities. If you do this type of exercise, you will BULK UP.

For example, let’s say our fictional human decides to become a MARATHON RUNNER. This is a type of AEROBIC exercise that burns an enormous amount of calories, plus the runner is active for hours at a time. This type of activity is NOT going to produce huge muscle gains like weight lifting. Your serious marathon runners are long and lean. In the horse world, this sport is most like ENDURANCE. Horses that train for endurance races generally get LEANER with increased training.

What if our fictional human chooses WEIGHT LIFTING? After the initial slim down phase, our person will begin “bulking up”. This means that muscles*** like the biceps, deltoids, quads, hamstrings, and gluteals will all begin to get bigger as they adapt to increasing loads. Weight lifting is an ANAEROBIC exercise, and puts different demands on the body than aerobic exercise does. Body builders typically lift very heavy, but do so with low repetitions and rest periods between sets. DRESSAGE is very similar to weight lifting. We ask our horses to collect (sit and lift), then give them plenty of rest breaks like free walks and stretchy circles. Horses that are put into an intensive dressage training program will bulk up in the muscles that are necessary for locomotion***.

***Note that targeted development of the Trapezius muscle in humans leads to neck and back pain and decreased range of motion of the cervical spine. Likewise, we do not want to see hypertrophy of the horse’s Trapezius muscle. Remember, the Trapezius’ primary function is to stabilize the cervical and upper thoracic spine, not movement.

What sport is SHOW JUMPING most like? Let’s say our fictional human decides to join the track team, and signs up for the 400m hurdles. During the race, he is expending a ton of energy (calories) by performing an aerobic activity (running, which means he will get leaner) coupled with the anaerobic activity of lifting his body weight over obstacles (which means he will have muscle growth). At first, we can expect him to become leaner overall, but as time progresses, the muscles he uses to propel himself over fences - his lower body (legs and gluteals) - will have moderate muscle growth as his body adapts. However, due to the primarily aerobic nature of the discipline, he won’t see the type of muscle growth an anaerobic weight lifter will. Likewise, horses that start a show jumping training program will become leaner and more uphill, but gain significant muscle in the hind legs and gluteals.

How about EVENTING? For this sport, our fictional human has decided to be a Triathlete. This means he trains equally in aerobic and anaerobic activities. You can expect to see him to have extremely low body fat, but have significant muscle gains in this arms, deltoids, Latissimus, gluteals, and legs. However, if he is training correctly, he will NOT have muscle growth in the Trapezius.


Let’s go back and look at the MYTHS from above.

MYTH: Any type of work - Dressage or Endurance - will produce the same type of muscle growth in a horse. Now that you can differentiate between AEROBIC and ANAEROBIC activity, you can look at the pictures and realize this is a fundamentally FALSE idea. We expect to see horses become leaner in Endurance, Show Jumping, and Eventing, and for horses to “bulk up” in Dressage.

FACT: Horses will get LEANER in the aerobic disciplines, not wider.

MYTH: Every horse will need a wider tree as they advance up the levels. Again, FALSE. I almost NEVER see horses in the aerobic disciplines getting wider as they journey from Green as Grass to the 5* level. I do occasionally see horses needing a slightly wider tree width as they go from dressage Training Level to FEI, but I suspect that is mostly due to the majority of USDF competitors riding Warmbloods - the type of horse who puts on weight easier and usually does not have as prominent withers as the leaner OTTBs. Remember that the Trapezius must be RELAXED in order for the horse to collect, so we should not see increased muscle mass here with work.

FACT: Many Endurance, SJ, and Eventers will need a NARROWER tree as they progress up the levels.

FACT: Horses will get wider in Dressage, but should not show significant development of the Trapezius due to its primary function as a stabilizing muscle.

MYTH: All breeds will develop the same way when put into the same type of work.

Have you ever known someone that could eat as much pizza as she wanted, and never get fat? (Yeah, I hate those b^tches, too.) Horses are the same. Every off the track thoroughbred (OTTB) owner mortgages the farm to pay the feed bill every month, while many Warmblood owners are asked daily if their horse is pregnant or “just fat” when they feed them barely a handful of pellets. It takes A LOT to get the same muscle gains on an OTTB as you will see in a Draft horse.

FACT: The hot blooded horses will not have the same muscle growth as a cold blooded horse under the same work conditions.

I’m not quite sure why the majority of us go to the gym with the expectation of becoming leaner, but when our horses do the same it is cause for concern? Remember that our bodies have the same physiological response to exercise because we are mammals.

Although having your horse get wider with work is certainly fine, don’t be surprised or upset when your Fitter says your horse needs a narrower tree despite being in heavy work. It likely means your training is paying off and you two are on the right path for correct development.

502 views1 comment

Recent Posts

See All
bottom of page