Community Contact
Contact About
MMThe Modern Meathead
Get the manual →
The Biomechanics Manual

Stop memorizing exercises. Start seeing them.

A 148-page visual guide to the principles underneath every exercise in the gym. Learn how to look at force, torque, movement, muscle bias, and stability so you can understand why an exercise works—and how to change it when it doesn’t.

Get The Biomechanics Manual$49 USD · one-time purchase
The Biomechanics Manual by Ben Yanes
The real goal

Biomechanics should give you a language for what you’re already looking at.

Most people see a bench press, a row, a squat, or a lateral raise as a category. This manual teaches you to look underneath the name: Where is the force? What is it trying to rotate? Where is the exercise heavy or light? What muscles can oppose it? Once you can answer those questions, the gym becomes a lot less mysterious.

The transformation

From collecting answers to being able to find them.

The point isn’t to give you another list of “best exercises.” It’s to teach you principles that transfer from one exercise, machine, body, and problem to the next.

Before
  • You recognize exercises mostly by their names.
  • You need someone else to tell you what an exercise “hits.”
  • Machines feel confusing when they look unfamiliar.
  • You know an exercise feels off, but can’t describe why.
  • You change technique based on rules, cues, or convention.
  • You see the implement more clearly than the forces acting on the person.
After
  • You can break an exercise into forces, joints, axes, and motion.
  • You can reason backward from a target muscle.
  • You can predict where an exercise will be heavier or lighter.
  • You can explain why two similar-looking exercises may load you differently.
  • You can change setup intentionally instead of guessing.
  • You have a framework for figuring out exercises you’ve never seen before.
A new way to look

Three questions change almost everything.

The manual repeatedly brings complex biomechanics back to simple first-principles reasoning.

01

Where is the force?

Identify where a force contacts the body and the direction it pushes or pulls. That gives you the starting point for understanding the exercise.

02

What is it trying to rotate?

Follow the force to the joint. Which rotation does the exercise create? Now you can work backward toward the muscles involved.

03

Where is the challenge?

Compare torque throughout the range. See where leverage increases, where it falls away, and how a small setup change can reshape the entire exercise.

The Rule of 90

Learn to see where an exercise gets heavy.

One of the most useful ideas in the manual is learning to compare the relationship between a force and a joint axis. Once you can see moment arms, you can begin to predict where an exercise challenges you most—and deliberately move that challenge.

At its simplest: when a force meets a segment at 90 degrees, that force has its best ability to rotate it.

Inside the manual

Eight foundations. One connected way of thinking.

The chapters build on each other so you’re not just learning definitions—you’re learning how to use them to understand real exercises.

01

How Muscle Works

Start with the central idea: muscle contraction is a response to force.

02

Force

Learn to identify point of contact and direction, then work backward from the effect on the body.

03

Torque

Understand rotational challenge, axes, moment arms, and why leverage changes throughout an exercise.

04

How We Move

See joints as rotations and bones as arcs instead of assuming your body follows the machine or weight.

05

Heavy VS Light

Learn why challenge changes through a range of motion and how to alter where an exercise is hardest.

06

Biasing Muscles

Reason from muscle action, fiber direction, stretch/shortening, and force to make an exercise more specific.

07

Stability

Understand anchors and opposing forces so you can see why support changes what the rest of the body has to do.

08

Feedback

Use what you notice in the real world to refine your understanding instead of treating theory as the final answer.

Who this is for

If you spend time in the gym, this changes what you notice.

For lifters

Stop blindly copying setups. Understand why an exercise feels the way it does, how to target the muscle you want, and what you can change when something isn’t working.

For coaches

Build a more precise language for what you’re observing so you can explain, adjust, and individualize exercises instead of relying on memorized rules.

For biomechanics nerds

Turn terms like force, torque, moment arm, axis, muscle bias, and stability into concepts you can actually use on the gym floor.

Feedback from readers

Complex ideas. Made usable.

★★★★★
“This book is phenomenal both in theory and practical application. The concepts you talk about are ones I’ve had both in my own head and also use in practice as a physical therapist. I’m so glad that someone has made the concepts of moment arms and lengthened vs shortened positions directly applied in an educational context.”
Michael · Physical Therapist
★★★★★
“The manual explains biomechanics in a very simple yet incredibly detailed way. I liked how it teaches principles through examples and tasks that actually got me to think for myself, which is why so much of it has stuck.”
Charlie
★★★★★
“The manual’s ability to simplify complex concepts and break them down into clear components is a game changer. I already have some of your products, and every time I read your stuff, the picture gets clearer.”
Thiago · Coach / PT
The Biomechanics Manual

Give yourself a map of the gym.

You don’t need another list of exercises to memorize. Learn the principles underneath them and give yourself a way to reason through the next exercise, machine, client, or problem you encounter.

$49 USD
Get The Biomechanics Manual

One-time purchase.

© The Modern MeatheadUnderstand lifting. Think for yourself.