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Variables What are they? What do they indicate? What are they for?

Variables What are they? What do they indicate? What are they for?

We will start by defining a variable as a characteristic that can take different values and be modified by different factors that influence it.

Although the variables are the essential analysis tool of the coach, today we will subdivide the variables into 3 groups. Depending on the function they fulfill in the training process, the moment in which they are observed or analyzed and the conclusions to which their interpretation can lead us.

Variables in real time (Observable during the session)

Result variables (obtained after training as a consequence of what was executed)

Analytical control variables (Result of the statistical and analytical process that involves the result variables)

Variables in real time:

They are those to which the athlete must be controlling and paying special attention during the execution of the session.

Volume: Refers to the amount of time in seconds elapsed ( h:min:sec )

Intensity: It talks about how much effort is being made (Watts, Fc and rhythm)

Execution: It tells us how we are achieving that intensity (Cadence, fluency and step length for athletes)

Balance: It indicates the contribution that each of our extremities is making in the generation of intensity (LEFT/RIGHT).

Energy: It is an indicator of the amount of effort accumulated over time (Kcal, Kjoules )

There will also be other related variables that will be very useful in making slightly more complex decisions: Speed, lactemia, glycemia, oxemia, Altitude, temperature, humidity, inclination and aerodynamic coefficient. These last variables will be of great importance within the competition since they will help us understand the best moments to follow the wheels, attack, change rhythm and even when and how to feed.

The most used within these real-time variables could be those related to intensity, volume, and execution.

Intensity – Power (watts): It refers to the intensity at which we pedal, meaning, how hard and how fast (Force*cadence).

Execution – Cadence (Rpm): It tells us how many complete pedal strokes we perform in 1 minute, the higher the cadence, the greater the neuromuscular and aerobic stimulus, on the contrary, the lower it is, the stimulus will be directed more towards force.

Balance ( Left / Right): Indicates how much is the difference % of power production between both legs. It will be ideal to observe in continuous segments of medium or long duration.

Result variables:

These variables will give us the summary and will tell us what the effect of the training applied on the athlete has been.

Volume: It refers to the amount of time used during the session ( H:mm:ss ), there will be the time elapsed from the beginning to the end and the effective time that will be the one during which some degree of intensity was being printed on the pedals.

Intensity: How intense was the session compared to the athlete’s ability (IF, NP, AVG watts )

Energy: It tells us how much metabolic energy we use in training (Kcal, Kjoules )

Load: How much stress was placed on the body as a result of the training session (TSS, HRTSS, rTSS )

The most used of these variables will be:
Training stress score (TSS): It refers to the total load of training, it means how much stress the body was subjected to during the session. This will be useful to study the relevance of whether a regenerative session should be applied and to keep track of the progressivity and undulation of the loads.

TSS Intensity Recovery
<150 Low Generally full recovery is achieved with in one day
150-300 Moderate Some fatigue may be present the day after, full recovery is achieved with in 48 h
300-450 High Some fatigue after 2 days
>450 Very high Probably the fatigue will last a lot of days

Table 1. Classification of training based on TSS points and the recovery required in each case (modified from Allen and Coggan , 2010)

Time in zones: It tells us how long we have stimulated each of the training zones, allowing us to understand where our adaptations will be directed.

Normalized Power (NP): It is the average of watts of the training or in a segment of it, excluding the peaks and valleys in the record, that is, without counting the sprints or the pedaling moments at zero.

Average Power: It is the final average of watts of the entire training, taking into account all the data, without counting the total pauses.

Intensity Factor (IF): It can tell us how intense the entire training was, but since it is calculated from the normalized power, it will underestimate those criterium-type competitions or sprint training, it is better to evaluate the IF in certain periods of time than in the entire session.

An IF greater than 1.05 in a 20-minute test or greater than 1 in a 1-hour effort will indicate that the threshold has increased. Assuming uniformity in its execution without many zeros in the power register, since the IF is calculated using the NP and not the average power.
The IF is a personal value since the intensity is compared against the threshold of each person.

Subject with previous ftp of 200 watts that moves 220 watts during a training session for 30 minutes = IF:1,1 is a subject whose ftp must be recalculated.

Analytical control variables:

These variables are given because of the statistical analysis of the load and will allow us to keep a macro control of how the state of Preparation: Fatigue of each athlete.
FTP (Functional Threshold Power):
It is the result of the analysis of an indirect effort test and it will be a number in theoretical watts that our athlete could maintain for approximately one hour. It is a value related to and close to the intensity of the ventilatory threshold 2 or the maximum stable state of lactate.
CTL (Chronic Training Load – 42 days):
With this variable we will be able to quantify how much we have trained and more precisely how much training load we have given to our system during the last 42 days.
ATL (Acute Training Load – 7 days):
It tells us about the intensity of the printed load during the last week and it will have a great relationship with the perceived fatigue since it is the recently accumulated stress closest to the day of the measurement.
TSB (CTL:ATL Training Stress Balance):
This value will allow us to analyze the balance between the chronically accumulated load and the result of the stress derived from the last sessions, the more negative the number, the greater the fatigue and the more positive the number, the greater the freshness. The ideal for the competition will be to arrive as chronically charged as possible (following the principles of progressiveness and undulation of the charge) and as fresh as possible.
The reference values for the ideal TSB when facing the competition will be between 10 and -10, the negative number being better for 1-day races and the positive number better for stage tests.


All the variables will only make sense if and only if the factors that condition them are adequate (sensor calibration, zone calculation and training thresholds).

-It’s not just accumulating charge and finding a balance. How we deliver and assimilate the load will be essential for the success of the process.

By Pablo Pulido – Methodological director of threshold experts sas .