Many coaches are familiar with long-term training load models such as CTL®, ATL® and TSB®. These metrics have been useful because they help coaches move beyond single-session analysis and understand training as a cumulative process.

Vekta Load & Strain solve a similar coaching problem, but with a different model of training demand.

The key difference is this:

CTL®, ATL® and TSB® are built from one combined stress score. Vekta separates volume-based load from intensity-based strain before looking at long-term trends.

That separation matters because two sessions can create similar total stress scores but very different physiological demands.

A long endurance ride and a short VO2max interval session may both be difficult. But they are difficult in different ways. They affect adaptation, fatigue, recovery and performance readiness differently.

Vekta is not trying to create a more complicated version of the same model. It is trying to preserve the parts of training demand that coaches already know are different: total volume, recent volume pressure and intensity strain.

In TrainingPeaks-style models, the starting point is TSS®, which assigns a training stress score to each workout based on duration and intensity relative to threshold.

CTL® and ATL® then apply different time windows to that same daily stress score. CTL® is typically used as a longer-term fitness or load estimate. ATL® is typically used as a shorter-term fatigue estimate. TSB® is calculated as the difference between the two and is often interpreted as “form.”

This structure is useful because it gives coaches a simple way to monitor trends:

Is the athlete building load?
Has recent training increased sharply?
Is the athlete carrying more short-term fatigue than usual?
Is training being reduced before an event?

The limitation is not the idea of rolling load. The limitation is the input.

If the single daily score does not fully describe the session, then every long-term metric built from that score inherits the same blind spots.

Traditional training stress models combine duration and intensity into one score.

That creates a practical coaching issue.

Two sessions can have a similar total score but create very different demands:

A long, steady endurance session may create a large volume-based load.
A shorter interval session may create high intensity strain.
A race-specific session may create both.

Those sessions should not always be planned, monitored or tapered from in the same way.

Vekta addresses this by separating the session into two signals:

Vekta Volume
The total work demand of the session: how much training was completed.

Vekta Intensity
The difficulty of the session: how hard the work was for that athlete.

This separation is the foundation of Vekta’s long-term model. Vekta does not first compress the session into one number and then smooth it. It preserves the distinction between volume and intensity, then tracks each signal over time. (Learn more)

Vekta uses exponentially weighted moving averages, like traditional performance-management models, but applies them to more specific inputs.

Instead of applying short-term and long-term time windows to one combined stress score, Vekta tracks volume and intensity separately. (Learn more)

What it is:
An 8-week exponentially weighted moving average of Vekta Volume.

What it tells you:
The athlete’s long-term volume-based training demand.

How to use it:
Use Load-8 to understand aerobic workload, base development, long-term consistency and the amount of training the athlete has recently adapted to.

Load-8 is the closest Vekta equivalent to the role CTL® often plays, but it is based specifically on volume rather than a blended stress score.

What it is:
A 2-week exponentially weighted moving average of Vekta Volume.

What it tells you:
The athlete’s recent volume accumulation.

How to use it:
Use Load-2 to identify short-term volume spikes, recovery needs, deload timing and rapid changes in training demand.

Load-2 overlaps with the role ATL® often plays, but it is volume-specific.

What it is:
A 2-week exponentially weighted moving average of Vekta Intensity.

What it tells you:
The athlete’s recent intensity profile.

How to use it:
Use Strain to identify when high-intensity work is stacking, when race-specific stress is increasing, or when fatigue risk is rising even if total volume is not especially high.

This is a major difference from CTL® / ATL® / TSB®-style models. Vekta gives intensity its own long-term signal instead of hiding it inside a combined score.

A single fatigue or form number may show that training stress has increased or decreased. But it may not show why.

Vekta separates the question into clearer parts:

Load-8 shows the athlete’s long-term volume preparation.
Load-2 shows recent volume pressure.
Strain shows recent intensity pressure.

This helps coaches distinguish between situations that may look similar in a single-score model but require different decisions.

A rise in recent training demand can come from different sources.

Load-2 rising while Strain is stable
The athlete is accumulating more volume, but intensity is not increasing much. Recovery may be needed, but the stress is mostly volume-driven.

Load-2 stable while Strain is rising
The athlete is not necessarily doing more total work, but recent sessions are harder. This can happen during sharpening phases, race-specific work or poorly balanced training weeks.

Load-2 and Strain both rising
The athlete is stacking both volume and intensity. This may be appropriate in a planned overload block, but it needs close monitoring.

These are different coaching situations. Vekta makes those differences visible.

A core problem with a single stress score is that it can imply different types of training are equivalent because they produce the same number.

But coaches do not treat all training stress as equivalent.

A five-hour endurance ride, a threshold session and repeated anaerobic intervals may all be demanding. But they do not create the same type of fatigue. They do not support the same adaptation. They do not require the same recovery strategy.

Vekta keeps those differences visible.

Volume tells you about the size of the training dose.
Intensity tells you about the difficulty and sharpness of the dose.
Load and Strain show how those patterns are accumulating over time.

High-intensity work does not scale neatly.

Small increases above critical power or critical speed can create disproportionately higher physiological strain. This is especially important when athletes are doing repeated high-intensity efforts, race-specific surges or sessions that draw heavily on finite above-threshold capacity.

Vekta Intensity is designed around that principle. It gives greater weight to work above CP/CS, uses athlete-specific scaling, accounts for cumulative fatigue and can adjust for environmental factors such as altitude.

This matters because intensity spikes are often where important coaching signals appear:

An athlete may be adding too much high-intensity work too quickly.
A session may be sharper than the total volume suggests.
Race-specific stress may be increasing.
Recovery needs may be higher than the weekly load total implies.

In a single-score model, those signals can be flattened.

Threshold is useful, but it does not fully describe an athlete’s physiology.

Two athletes can have the same threshold but very different capacities above threshold. One athlete may tolerate repeated surges well. Another may fatigue quickly once work exceeds CP/CS.

Vekta Intensity uses athlete-specific inputs such as CP/CS, W′/D′ and Pmax. This makes the intensity score more sensitive to the athlete’s actual profile rather than assuming all athletes respond similarly once relative threshold is accounted for.

TrainingPeaks uses TSB® as a “form” score by subtracting short-term load from long-term load. In simple terms, when recent training drops below long-term training, TSB® rises.

This can be useful during a taper because it shows that acute training stress is falling relative to the athlete’s longer-term load.

But it creates a problem if the number is interpreted too literally.

A high form score does not automatically mean the athlete is ready to perform well. It often means the athlete has reduced recent training. Taken to the extreme, a form score can continue improving simply because training has been reduced. But reduced training is not always the same as improved readiness.

Freshness is not the same as readiness.

Readiness requires the athlete to reduce unnecessary fatigue while maintaining the physiological, neuromuscular and event-specific qualities needed for performance.

A good taper should reduce accumulated pressure without removing the training signals that keep the athlete sharp.

This is why Vekta does not reduce tapering or readiness to one balance number.

A TSB®-style form score can encourage the wrong question:

“How high can we get the form score?”

That is not the same as asking:

“What is the athlete ready to do?”

A very high form score may reflect low recent training rather than optimal race preparation. The athlete may be rested, but also under-stimulated. They may have reduced fatigue, but lost rhythm, intensity tolerance or event-specific sharpness.

For endurance performance, the goal is usually not to eliminate training stress. The goal is to control it.

That means reducing the right type of pressure at the right time.

A taper should usually lower recent volume load while preserving enough race-relevant intensity to maintain readiness. A single form score can hide this distinction because it treats reduced training stress as universally positive.

Vekta separates the tapering question into clearer parts:

Is recent volume pressure dropping?
Look at Load-2.

Is the athlete still receiving enough race-relevant intensity?
Look at Strain and the structure of the final sessions.

Does the athlete have enough long-term preparation behind them?
Look at Load-8.

During a taper, Load-2 is the primary Vekta metric for monitoring the reduction in recent volume pressure.

Because Load-2 reflects recent volume-based demand, it should usually decline as the athlete moves toward a key event. This shows that the coach is reducing accumulated workload and allowing fatigue to fall.

But the goal is not to drive Load-2 as low as possible.

A useful taper allows Load-2 to fall enough to reduce fatigue while avoiding a complete loss of training rhythm. The right decline depends on the athlete, the event, the previous training block and the athlete’s response to reduced volume.

Use Load-2 to answer:

Has recent volume pressure come down enough?
The athlete should arrive at the event with less short-term volume pressure than during the build or overload phase.

Has the reduction happened gradually enough?
A sudden collapse in Load-2 may indicate that too much training has been removed too quickly.

Is the athlete still receiving the right stimulus?
Load-2 may fall while carefully selected intensity sessions remain in the plan.

Does the taper match the athlete’s history?
Some athletes perform best after a larger reduction in volume. Others feel flat if Load-2 falls too far.

Load-2 should not be interpreted alone. The taper becomes clearer when Load-2 is read alongside Strain.

A good taper will often show:

Load-8 remains relatively stable
The athlete still carries the long-term preparation from the previous training block.

Load-2 trends downward
Recent volume pressure is being reduced.

Strain is maintained or reduced more selectively
The athlete keeps some race-relevant intensity without accumulating excessive intensity pressure.

This distinction is important.

If both Load-2 and Strain fall too sharply, the athlete may become rested but lose sharpness.

If Load-2 falls but Strain remains very high, the athlete may reduce volume but still carry intensity-related fatigue.

If Load-2 stays high, the athlete may not unload enough before the event.

The goal is not the highest possible freshness score. The goal is the right balance of reduced volume pressure, controlled intensity exposure and maintained event-specific readiness.

Load-8 stable, Load-2 falling, Strain controlled
This is often the desired taper pattern. The athlete still carries long-term preparation, recent volume pressure is falling and intensity is being managed.

Load-8 stable, Load-2 falling sharply, Strain very low
The athlete is unloading, but may be losing too much rhythm or sharpness. This may be appropriate for some athletes, but it should be checked against the athlete’s previous taper responses.

Load-8 stable, Load-2 falling, Strain high
Volume has been reduced, but intensity may still be creating fatigue. This can happen when too many sharp sessions are kept in the taper.

Load-8 falling, Load-2 very low, Strain very low
The athlete may be moving beyond tapering and into detraining. This may produce freshness, but not necessarily readiness.

Load-2 high close to the event
The athlete may still be carrying too much recent volume pressure. This can be appropriate for some lower-priority events, but it may compromise performance for an important race.

Conceptually, Vekta is solving a similar problem: understanding how training accumulates over time.

But it is not a one-to-one replacement.

When using Vekta, coaches should stop asking only:

“Is the athlete’s load going up or down?”

They should also ask:

“What type of load is changing?”

Use Load-8 to understand long-term volume adaptation.
Use Load-2 to monitor recent volume pressure.
Use Strain to monitor recent intensity pressure.

CTL®, ATL® and TSB® helped coaches think about training as a cumulative process. That idea remains valuable.

Vekta builds on that idea with more specific inputs.

Instead of using one combined stress score to represent every type of training demand, Vekta separates volume from intensity and tracks both over time. This gives coaches a clearer view of what the athlete is adapting to, where fatigue is coming from and what should change in the next block.

Load-8 tells you what long-term volume preparation the athlete is carrying.
Load-2 tells you how much recent volume pressure is accumulating.
Strain tells you how hard the recent training has been.

Together, they give coaches a more precise way to manage progression, recovery, tapering and performance readiness.

Training Stress Score® / TSS®, Chronic Training Load® / CTL®, Acute Training Load® / ATL®, and Training Stress Balance® / TSB® are registered trademark terms owned by TrainingPeaks, LLC.