Step Loading: From Movement Efficiency to Force Expression

Long-term strength development requires both intermuscular and intramuscular coordination. The athlete needs to become more efficient at coordinating the movement pattern while also improving the ability to activate the musculature responsible for producing force within that pattern. Step Loading allows both qualities to be emphasized within the same A Series by progressing from technically precise, submaximal exposures toward heavier sets requiring greater force expression.

When developing strength, two massively important variables need to be considered: intermuscular coordination and intramuscular coordination.

Both are neurological qualities. Both influence force production. Both contribute to long-term strength development.

However, they do not describe the same thing, and they are not emphasized in exactly the same way within training.

Intermuscular coordination refers to the ability of different muscle groups to work together efficiently during a movement. It involves the nervous system coordinating prime movers, synergists, stabilizers, and antagonists to produce a complex movement with precision and efficiency.

In the context of strength training, intermuscular coordination is a major reason someone becomes more technically proficient and more efficient at performing specific lifts over time.

Intramuscular coordination refers to how the nervous system controls and activates muscle fibers within a single muscle. It relies primarily on motor unit recruitment, firing rate, and synchronization. These qualities determine how effectively a muscle can express force once the movement pattern itself is being coordinated efficiently.

Both matter.

Strength is not developed only by making muscles larger, and it is not developed only by practicing technique. Long-term strength development requires the athlete to improve the coordination of the movement pattern and the ability to activate the musculature responsible for producing force within that pattern.

This is one of the reasons Step Loading works so well for A Series exercises.

It allows the athlete to train both ends of the coordination spectrum within the same primary loading structure.

Intermuscular Coordination: Becoming More Efficient at the Lift

Intermuscular coordination allows a trainee to become more efficient at completing a specific lift.

Early in the training process, this is easy to appreciate. A new trainee improves rapidly because they are learning how to coordinate the movement.

They learn how to brace, maintain position, distribute force, control the eccentric, transition effectively, and produce force through the correct pattern. The lift becomes more efficient because the nervous system becomes better at organizing the muscles involved.

However, intermuscular coordination does not stop mattering once basic technique has been established.

This is where Bompa’s explanation of intermuscular coordination becomes especially valuable and what made me take notice of its importance in long-term strength development.

Bompa states in Periodization Training for Sports:

“Intermuscular coordination, on the other hand, is the capacity of the nervous system to coordinate the ‘rings’ of the kinetic chain, thus making the gesture more efficient. With time, as the nervous system learns the gesture, fewer motor units get activated by the same weight, which leaves more motor units available for activation by higher weights. Therefore, to increase the weight lifted in a given exercise over the long term, intermuscular coordination training (technique training) is the key.”

To phrase this slightly differently, as the nervous system becomes more efficient at coordinating the lift, less unnecessary muscular activity is required to complete the same task.

This improves force transfer, reduces wasted effort, and increases the athlete’s ability to express force as loading increases.

This is a critical concept for long-term strength development.

If a trainee can lift the same weight with greater efficiency, that load no longer requires the same neurological cost. The movement becomes cleaner, more repeatable, and less wasteful.

More of the available force-producing capacity can then be directed toward lifting heavier loads rather than simply managing poor coordination or an inefficient movement strategy.

In practical terms, intermuscular coordination improves the athlete’s ability to perform the lift well.

It improves technical proficiency, movement efficiency, timing, bracing, stabilization, and force transmission across the entire system.

For primary compound movements, this is essential because strength is not expressed by one muscle in isolation. It is expressed through a coordinated movement pattern.

Intermuscular coordination is generally best trained with submaximal loads, often below approximately 80% of 1RM, with sets kept far enough away from failure that movement quality remains high.

The goal is not to grind. The goal is to rehearse the lift with enough load to matter, but not so much load or fatigue that execution deteriorates.

This type of work builds the efficiency that future strength expression depends on.

Intramuscular Coordination: Expressing More Force

Only training intermuscular coordination would be a mistake.

Strength development also requires intramuscular coordination. Once the movement pattern is efficient, the athlete still needs to improve the ability to activate the muscle fibers responsible for producing force.

Intramuscular coordination includes three primary components: motor unit recruitment, firing rate, and synchronization.

Motor Unit Recruitment

Motor unit recruitment refers to the ability to activate more motor units within a muscle.

This is a major contributor to force development as loading increases toward approximately 80% of 1RM. As demand rises, the nervous system recruits additional motor units to produce more force.

This is a learned skill. Jurgen Hartmann and Harold Tunnemann state in their book Fitness and Strength for All Sports that elite throwers have been found to be able to recruit 85–90% of their entire motor unit pool, whereas the untrained population can only recruit about 60%.

Firing Rate

Firing rate, often referred to as rate coding, refers to how frequently motor units discharge.

This becomes increasingly important as intensities move above roughly 80% of 1RM and closer to maximal loads.

Once high levels of recruitment have occurred, increasing firing frequency becomes one of the major ways the nervous system continues to increase force output.

Synchronization

Synchronization refers to the timing of motor unit activation.

Improved synchronization can contribute to more coordinated force expression within the muscle, particularly under high-force demands.

These qualities are generally trained more effectively with heavier loads, commonly above 80% of 1RM.

At these intensities, the nervous system is required to recruit higher-threshold motor units, increase firing rate, and coordinate force expression under more demanding conditions.

This is where intramuscular coordination becomes essential for displaying higher levels of strength.

Intermuscular coordination improves the efficiency of the movement.

Intramuscular coordination improves force-producing expression within the muscles responsible for the movement.

A strong A Series structure can take advantage of both.

How Step Loading Integrates Both Qualities

Step Loading is one of the most effective ways to integrate both intermuscular and intramuscular coordination into the same primary exercise.

When we Step Load, we generally recommend a 7.5–12.5% intensity spread across the working sets. This can be higher or lower depending on the total number of sets prescribed, the goal of the phase, and the strength level of the athlete, but this range is a common and practical starting point.

The purpose of this intensity spread is not just to make the loading look organized on paper.

It changes the emphasis of the session across the working sets.

The early sets are usually lighter, more technically manageable, and farther away from failure. These sets create an opportunity to emphasize intermuscular coordination.

The athlete can rehearse the movement with meaningful load while maintaining high levels of technical precision, positional control, and execution quality.

As the sets progress and load increases, the emphasis gradually shifts toward intramuscular coordination.

The heavier sets create higher demands for motor unit recruitment, firing rate, and synchronization. The athlete is no longer only rehearsing the movement efficiently. They are now required to express force at higher intensities.

This is the value of Step Loading.

It creates a bridge between efficient practice and high-force expression within the same A Series exercise.

Example: 5 × 5 Step Loading Toward a 5RM

Take a simple example: 5 sets of 5 reps with a 10% intensity spread, progressing toward a 5RM load on the final set.

A 5RM is commonly associated with approximately 85% of 1RM. For simplicity, imagine the athlete’s 5RM load is 100 kg.

Using a 10% intensity spread, the session may look like this:

• Set 1: 90 kg × 5

• Set 2: 92.5 kg × 5

• Set 3: 95 kg × 5

• Set 4: 97.5 kg × 5

• Set 5: 100 kg × 5

If 100 kg represents approximately 85% of 1RM, the athlete’s estimated 1RM would be roughly 117.5 kg.

The loading structure would therefore look approximately like this:

• Set 1: 90 kg × 5, approximately 76.5% of 1RM

• Set 2: 92.5 kg × 5, approximately 78.5% of 1RM

• Set 3: 95 kg × 5, approximately 80.8% of 1RM

• Set 4: 97.5 kg × 5, approximately 83% of 1RM

• Set 5: 100 kg × 5, approximately 85% of 1RM

In this example, the first two sets fall below 80% of 1RM and are performed with meaningful repetitions in reserve.

These sets are not just warm-ups, they are productive exposures. The loads are heavy enough to reinforce the movement pattern under meaningful demand, but light enough that fatigue should not compromise execution.

This makes them well suited for emphasizing intermuscular coordination. The athlete can focus on bracing, position, bar path, tempo, timing, and efficient force transfer.

Set 3 at 95 kg represents the transition point.

The load is now slightly above 80% of estimated 1RM, and the athlete is likely moving closer to the point where intramuscular coordination becomes more emphasized.

Technical efficiency still matters, but the demand for motor unit recruitment, firing rate, and synchronization is increasing.

Sets 4 and 5 bias intramuscular coordination more clearly.

The loads are now close to the athlete’s repetition maximum. The final set at 100 kg represents the 5RM exposure, meaning the athlete is working with minimal repetitions in reserve.

These sets create the highest demand for motor unit recruitment, firing rate, and synchronization.

Across the full A Series, the athlete has not simply completed five sets of five.

They have moved through a progression of neurological emphasis.

The early sets emphasize efficient coordination of the lift.

The later sets emphasize force expression within that coordinated pattern.

Step Loading Versus Straight Sets

This is one of the reasons Step Loading can be more sustainable than performing all working sets at the same top load.

If the athlete attempted to perform 5 sets of 5 at 100 kg, every working set would be maximal. The intramuscular coordination demand would be extremely high from the start, but fatigue would accumulate rapidly.

Technical quality may deteriorate, bar speed will drop, and the chances of completing all of the prescribed volume are pretty nonexistent.

Step Loading creates a more gradual increase in demand.

The athlete accumulates high-quality volume before reaching the heaviest sets. The early exposures build technical consistency and movement efficiency. The later exposures challenge the nervous system to express higher force.

The total session still contains heavy loading, but the fatigue cost is distributed more intelligently.

This matters because strength development is not only about how heavy the final set is.

It is also about how much high-quality work was performed before that final set, how well the athlete maintained execution, and whether the session can be repeated and progressed across the mesocycle.

Why This Matters for the A Series

The A Series usually contains the primary compound movement of the session.

This is where exercise execution, loading progression, and long-term strength development matter most.

For this reason, the A Series needs to create high-quality exposure to the movement pattern while also developing the ability to express higher levels of force.

Step Loading fits this requirement extremely well.

The first sets provide an opportunity to refine the movement under meaningful but manageable load. This supports intermuscular coordination.

The later sets provide exposure to heavier loading and higher neural demand. This supports intramuscular coordination.

The exercise is practiced.

Then it is challenged.

If the athlete jumps immediately to the heaviest load, they may miss valuable rehearsal opportunities and accumulate fatigue too quickly.

If the athlete never reaches heavier loading, they may improve efficiency but fail to sufficiently challenge the neural qualities required to display strength.

Practical Application

When using Step Loading for A Series strength development, the goal is not simply to reach a top set.

The goal is to create a sequence of exposures that progressively shifts the emphasis from movement efficiency to force expression.

Early sets should be performed with high technical intent. The athlete should control the eccentric, maintain technical efficiencies, apply intended maximal concentric acceleration, and avoid unnecessary fatigue.

These sets should feel explosive, not maximal.

Final sets should expose the athlete to the highest loads of the session.

These sets place greater demand on motor unit recruitment, firing rate, and synchronization. The athlete is now expressing force within the pattern that was rehearsed earlier in the session.

These sets can feel like a grind, but technique should remain solid.

This is why intensity spread matters.

A 7.5–12.5% spread allows the coach to create meaningful differences between early and late sets without making the early sets too light or the final sets too aggressive.

The exact spread should be adjusted based on the number of sets, the rep bracket, and the training age of the athlete.

More sets may require a wider spread to manage fatigue.

Fewer sets may require a tighter spread to ensure enough meaningful exposure.

The principle remains the same.

The loading structure should allow the athlete to build coordination early and express force later.

Building Efficiency Before Expressing Force

Step Loading the A Series is not just a way to organize load progression.

It is a way to train both intermuscular and intramuscular coordination within the same primary exercise.

The early sets allow the athlete to rehearse the lift with meaningful load while maintaining technical quality and substantial repetitions in reserve. This emphasizes intermuscular coordination by improving efficiency, timing, stabilization, and force transfer across the movement pattern.

The later sets expose the athlete to higher intensities and lower repetitions in reserve. This emphasizes intramuscular coordination by increasing the demand for motor unit recruitment, firing rate, and synchronization.

Together, these qualities create a more sustainable pathway for strength development.

Intermuscular coordination helps the athlete lift more efficiently.

Intramuscular coordination helps the athlete express more force.

Step Loading allows both to be trained within the same A Series structure.