Exercise = Forces Applied to Anatomy

When we talk about exercise design, prescription, and application, we are talking about applying forces to anatomy.

That's it. Forces meeting a body. The body responding to those forces.

Tom Purvis, the founder of RTS, puts it this way: exercise is internal force production in response to external force application. It's not a movement pattern. It's not a name. It's a force relationship.

What's Inside an Exercise?

Every exercise - from running to yoga to bodybuilding - can be broken down into its composite pieces. What motion is occurring? What position is the body in? What are the resistance properties? These are some of the key variables that matter.

That's what's inside every exercise. The name is just a label.

Why This Matters

Anatomy is a function of gravity. That phrase comes from a physics textbook, but it captures something profound. If you look at a cross-section of a  femur, the bone density patterns aren't random - they reflect force history. Where forces have been applied repeatedly, bone has responded by becoming denser.

Your client's body works the same way. It responds to the forces you apply - not to the exercise name you call it.

So when a client can't feel their glutes in a hip thrust, maybe it's not about the amount of force. Maybe it's about the direction of force. If the way they are pushing is creating a bigger challenge to the quads, the nervous system will organise around the most effective solution available. Change the direction, change the demand.

The same thinking applies to all of our clients' goals.

When working with someone on bone density, the question isn't 'which exercise is good for osteoporosis?' It's: which bone are we targeting, what forces does that bone normally experience, and how do we design something to encourage adaptation?

The Shift

Exercise names are shortcuts. Useful for communication, but limiting when they become the unit of thinking.

A Pilates reformer and a leg press look different, but mechanically they're asking similar questions of the body. A Romanian deadlift and a cable hip hinge might share a name family, but they're different force environments.

The equation doesn't tell you what to prescribe. It tells you what matters.

What motion is actually available? What position gives us the resistance relationship we need? Where does the force change through the range? What is this client's anatomy capable of responding to?

Those questions lead somewhere. Exercise names lead to recipes.

This is where we start.