In this post, we’re going to break down training intensities and how they relate to three key methods used to develop strength and power. Each method serves a different purpose but ultimately contributes to the same goal: helping you move more weight, build more muscle, and get faster and stronger.
The Three Main Training Methods
Maximum Effort Method – Lifting maximal loads (heavy weights) for 1–3 repetitions.
Dynamic Effort Method – Lifting submaximal weights with the intent to move them as fast as possible (also known as speed work).
Repetition Method – Performing as many reps as possible to near failure.
Each of these methods trains different qualities of strength but also complements the others. When implemented correctly, all three recruit maximum motor units.
What Are Motor Units — and Why Do They Matter?
A motor unit is made up of a single nerve and the muscle fibers it controls. That nerve might control just a few fibers (for fine movement) or thousands (for forceful contractions). The human body contains approximately 250–300 million muscle fibers and 400,000 to 1 million motor units that control them.
Imagine a steel cable: it’s not one solid strand, but hundreds or thousands of tiny wires wound together. A muscle works similarly — made up of many fibers grouped into motor units.
We aim to recruit as many motor units as possible because doing so activates more muscle fibers, producing more force. Muscle fibers operate in a binary way — they are either on or off. There's no partial activation. If less force is needed, fewer motor units are recruited. As force demands rise, more motor units are called into action.
The Size Principle
The Size Principle describes the order in which motor units are recruited:
It starts with small, slow-twitch fibers (low force, long duration).
As intensity increases, the body recruits larger, fast-twitch fibers (high force, short duration).
These high-threshold motor units are only activated during near-maximal or explosive efforts — and they’re essential for building maximum strength and power.
Example: Walking vs. Sprinting
Let’s use locomotion to illustrate:
Walking activates only 10–30% of your muscle fibers. It’s low effort but sustainable for long periods.
Sprinting, on the other hand, activates 80–100% of your muscles — recruiting the largest, most powerful fibers. However, this effort can only be sustained for about 5–10 seconds.
How Does This Tie Into Training?
To get stronger and more powerful, you need to tap into the high-threshold motor units.
Take the squat as an example:
Maximum Effort Method – Work up to a heavy single, double, or triple (e.g., a 1RM).
Dynamic Effort Method – Perform squats at submaximal weight with maximum speed and intent.
Repetition Method – Use a moderate weight and perform as many reps as possible near failure.
Each method, if performed with maximum intent, will recruit high-threshold motor units. This not only builds strength but also trains your body to coordinate global contractions — engaging your nervous system and multiple muscle groups together.
Each method emphasizes different qualities of high-threshold motor unit recruitment:
Max effort builds coordination and absolute strength.
Dynamic effort builds rate of force development (how fast you can apply force).
Repetition method builds muscle size and endurance under fatigue.
All three methods are complementary. Ignoring one means leaving a critical part of your strength and power development on the table.
Practical Application
Every exercise in your training should fall into one of these three categories. However, submaximal effort is sometimes necessary before applying maximal methods. For example:
If someone’s form isn’t technically sound
If they’re recovering from injury
If they lack basic control or coordination
If they are prone to injury
Some exercises can be safely pushed hard (e.g., banded triceps extensions), while others (like deadlifts) carry more risk and require foundational skill and control.
Form always comes first. Maximal effort means nothing if it’s performed with poor mechanics.