Can We Really Ride Lighter? Understanding Rider Weight, Force and Pressure in the Saddle

“Ride lighter.” “Take your weight out of the saddle.” “Don't sit so heavily.”

These are all familiar phrases in riding, and most of us probably understand what somebody is trying to achieve when they use them. Sometimes they are simply coaching imagery - an instruction intended to create a particular response rather than a literal description of what is happening to the rider. But looking at these instructions through rider biomechanics and basic physics raises an interesting question: can we actually take our weight out of the saddle while still sitting in it?

Imagery can be useful, but it is important to understand the difference between what something feels like, what a cue is trying to achieve and what is actually happening mechanically. If we take “ride lighter” literally, there is an immediate problem - we can't actually ride lighter than we weigh. If we reduce the support underneath our seat, our body weight hasn't disappeared. It has to be supported somewhere else. And once the horse starts moving, the question becomes more interesting again, because now we aren't only dealing with the rider's gravitational weight - we are also dealing with the forces involved in accelerating and decelerating the rider's mass.

Rider weight in the saddle - what can actually change?

To understand this, we first need to separate mass, weight and force. Mass is measured in kilograms, so if a rider has a mass of 70 kg, they remain a 70 kg person whether they are standing on the ground, sitting in the saddle or standing in their stirrups. Weight is the force produced by gravity acting on that mass and can be described as weight = mass × gravitational acceleration (W = mg). So while we commonly talk about a rider “weighing 70 kg”, kilograms actually describe their mass. Their weight is a force, measured in newtons.

For riding, the important point is that changing our position doesn't change our mass or make gravity stop acting on it.

If that rider sits quietly in the saddle on a stationary horse, something has to support their body weight. If we temporarily ignore the stirrups, that support comes from the saddle underneath their pelvis. The rider doesn't need to actively push down into the saddle to create their body weight, just as we don't need to push ourselves down into a chair when we sit on it. Gravity is already acting on us and the chair simply provides the external support that stops us continuing towards the floor. In the same way, the saddle can support the rider without the rider actively pushing themselves into it.

Allowing the saddle to support our body weight is not the same as actively driving our weight down into the saddle.

Once the feet are placed into the stirrups, however, another route of support becomes available. If the rider takes more support through their feet, less support is required directly underneath the pelvis. Continue that process far enough and eventually the pelvis can lift completely away from the saddle. There may now be very little pressure underneath the rider's seat, but their mass hasn't changed, gravity hasn't changed and their body weight hasn't disappeared.

What has changed is how their body is being supported and how the forces are transmitted through the horse-saddle-rider system.

In either situation, the rider's weight ultimately still has to be supported by the horse through the saddle. The saddle's role is to distribute those forces over a larger area of the horse's back, rather than concentrating them at the smaller areas where the rider interacts with the saddle. This is where it is useful to separate pressure from force:

Pressure = force ÷ area

The same force distributed over a larger area produces less pressure at any one point. So reducing the pressure underneath the rider's seat does not mean their weight has disappeared from the horse's back. The forces may simply be entering the saddle differently and being distributed across a different area.

Less pressure under the seat does not mean less rider weight being carried by the horse.

Standing up from a chair is useful here because the same principle is much easier to recognise on the ground. When we are sitting normally, the chair provides much of our support while our feet are also in contact with the floor. As we begin to stand, our body position changes, our legs produce force against the ground and progressively more support is transferred towards our feet until the pelvis leaves the chair. We can stop halfway and hold ourselves there, but we haven't somehow become lighter while remaining normally seated - we have changed our position and are using muscular force to maintain a partially raised position.

The same continuum exists in riding. At one end we can be sitting in the saddle and at the other we can be standing in the stirrups, with positions such as half-seat and the rising phase of rising trot existing between those two ends. As the rider changes position, the contribution from the seat and stirrups changes as a consequence. If we measured the forces underneath the seat and feet, we might find a particular distribution, but that measurement describes the result of how the rider has organised their body at that moment. It doesn't necessarily mean that selecting an arbitrary percentage should be the starting point for organising the rider's position.

This is where telling a seated rider to “take some weight out of the saddle” can become confusing. If they deliberately reduce the support underneath their pelvis, something else has to provide that support, so they may push more through the stirrups, increase muscular effort through the legs, change their joint positions, alter the position of their centre of mass or begin to lift the pelvis towards a hovering position.

They haven't reduced their body weight - they have changed how that weight is being supported.

 That isn't inherently wrong: in half-seat, jumping position or the rising phase of rising trot, transferring more support towards the stirrups is part of the position and has a mechanical purpose. But if the task is to remain sitting in the saddle, deliberately trying to offload the seat starts to change the very position we are trying to maintain.

What changes when the horse starts moving?

So far, we have deliberately considered a stationary horse and rider. That's important, because we need to understand what happens when horse and rider are still before we add the additional forces involved when the horse starts moving. Once the horse moves, the rider still has the same mass and gravitational weight, but now that mass has to move too.

The horse's limbs apply forces against the ground, the ground applies forces back onto the horse, and the horse's body and saddle move upwards, downwards and forwards and change orientation throughout every stride. If the rider is going to travel with the horse, their body has to move too, which means their mass has to be continually accelerated and decelerated.

This is where Newton's second law becomes useful: force = mass × acceleration (F = ma). In simple terms, the forces involved in changing the movement of something depend both on how much mass there is and how quickly that movement is changing. A heavily loaded shopping trolley requires more force than an empty one to achieve the same acceleration, but even with exactly the same trolley, changing its movement quickly involves greater acceleration than changing it more gradually. The mass can remain exactly the same while the forces involved in moving it change.

The same principle applies to the rider. A 70 kg rider does not produce one constant rider-horse interaction force throughout every stride of trot or canter. Their gravitational weight remains approximately the same, but that 70 kg mass is now moving, accelerating and decelerating.

The rider's weight hasn't changed, but the forces exchanged between horse and rider can. 

This is an important distinction because it means body mass is part of the equation, but it doesn't tell us everything about the interaction between a rider and a moving horse.

Imagine two riders who both have a mass of 70 kg. On a stationary horse their gravitational weight is the same, but once the horse starts moving, those two bodies may not move in the same way. One rider may coordinate their movement relatively well with the movement of the horse and saddle, while another may repeatedly move away from the saddle and then reconnect with it. Their mass hasn't changed, but the movement of that mass relative to the saddle has. If the rider is moving relative to the saddle when contact is re-established, that relative movement has to change as horse and rider come back together, and if that change in velocity occurs quickly, the acceleration or deceleration involved can contribute to a larger peak in force.

That doesn't mean maintaining contact automatically produces lower forces, or that the aim is to make the rider's body completely still. Quite the opposite - a rider sitting on a moving horse has to move. Their mass has to accelerate and decelerate if it is going to travel with the horse. The skill is therefore not avoiding movement or avoiding force, but becoming better at controlling and coordinating that movement.

So what does being a “light” rider actually mean?

This is where the language we use becomes important. A heavier rider has greater gravitational weight than a lighter rider, and skill cannot make that difference disappear. A 90 kg skilled rider cannot somehow make themselves weigh 60 kg, just as a 60 kg rider doesn't suddenly weigh 90 kg because they bounce. But body mass alone does not tell us everything about the forces exchanged between horse and rider once movement is involved, because how that mass moves matters too.

So when we describe a skilled rider as looking or feeling “light”, perhaps weight isn't actually the variable we are describing. What we may be seeing is a rider who is better able to manage the movement of their mass and therefore the forces associated with that movement. That is quite different from physically trying to remove weight from the saddle, and the distinction matters because the words we use influence what riders actually do. If somebody is told simply to “take weight out of the saddle”, it is perfectly logical for them to push into the stirrups, increase muscular effort through the legs or begin to hover slightly above the saddle. But if they are supposed to be sitting, that may not be what we wanted them to do at all.

So there are really three separate ideas that shouldn't be confused:

• Changing where the rider is supported does not make their body weight disappear.

• Changing the rider's position changes how forces are distributed between the seat and stirrups.

• Once the horse moves, the rider's mass has to accelerate and decelerate, so the forces exchanged between horse and rider change even though the rider's mass does not.

Perhaps, then, becoming a “lighter” rider isn't really about becoming lighter at all. It is about becoming better at managing the mass we already have and the forces associated with moving it. And that leads to the next question. If we are sitting on a saddle that is itself moving and accelerating underneath us, should we actually be trying to take our seat away from it?

In the next article, I'll look at why I want the seat bones to stay in contact with the saddle when we are sitting, and why maintaining that contact is very different from pushing down or “sitting heavily”.

If you want to understand more of the anatomy, biomechanics and physics behind your riding, Riding Ready takes these concepts further and helps you develop the understanding, body awareness and physical ability to apply them. If you want to work specifically on your own riding, Rider Physio sessions use simulator, video and sensor feedback to identify what your body is doing and work on the control needed to change it. And SymmFit helps make rider position and asymmetry easier to see - because you can't change what you can't see.