Limit the Load: how much can horses carry?

The amount of load a horse can carry on his back is generally measured as a percentage of bodyweight, despite how muscular, fit, and spunky he might appear. Decades ago, the U.S. Cavalry advised that horses not carry more than 20 percent of their own bodyweight. At figures above that, horses demonstrated clear and measurable strain.

More recently, researchers arrived independently at this same percentage— 20 percent— and published their findings in the Journal of Equine Veterinary Science. When asked to carry heavier loads, horses showed signs of stress in subsequent days. These markers included bone stress, sore muscles, elevated heart rates and fatigue. As someone who helps horses become fitter and more comfortable in their bodies, I frequently see them hindered by this issue of load. The plain truth is that horses cannot make positive adaptations if they are under too much load. Instead, they torque joints, form poor movement patterns, and end up sore.

Fortunately, calculating your own horse’s load limit is simple math. Maybe less fortunately, many riders might not be realistic when it comes to estimating their own weight including all their tack and gear. Competitive endurance riders and jockeys might be the only ones I know who routinely step on a scale while carrying their saddle, bridle and boots. Remember, the whole load cannot be more than 20 percent. Let’s run some numbers, just to clarify.

An 800-pound Arabian should carry no more than 160 pounds total. A 15.1-hand Quarter Horse that weighs 1,000 pounds should carry no more than 200 pounds. Given that many Western saddles weigh nearly 40 pounds, that means the rider only gets 160 pounds in this equation. And, remember, that doesn’t mean 160 naked pounds on your bathroom scale at home. It means 160 pounds in your riding pants, boots, spurs, etc. Your vet can accurately tell you how much your horse weighs. From there, it’s up to you to figure out how much of his bodyweight he is being asked to carry on his back.

Beyond the fact that horses CAN carry up to 20 percent of their bodyweight, I would like to consider the nuances of this number. Twenty percent of bodyweight is widely accepted as the maximum load. It is worth considering that a horse being asked to carry its maximum load every day might not be thriving. Would it not be better for him to carry LESS than the upper end of his physical limits?

Here is where I like to make human analogies. Let’s say your maximum effort when bench-pressing is 100 pounds. Does this mean that your body will enjoy doing repetitions of that maximal effort day after day after day? I would like to raise the point that, no, most bodies do not function well at their maximum effort continuously. Instead, they thrive by occasional days at maximum effort followed by days of less strain where movement can flow easier, joints are less burdened, and soft tissues can glide more freely.