Training Load, MP4, Fitness, Fatigue, Form and Performance Potential

Training Load

Training Load (Load) is the accumulation of training stress. To compute your training load, Athletica combines markers of intensity (i.e., speed, power, heart rate) determined from the zone measurements with the actual time spent exercising or the distance covered across the various pre-established intensity zones outlined. These are ultimately used to determine your fitness, fatigue and form levels described below.

Fractional Training Intensity

Fractional Training Intensity (FTI) is a measure of the intensity of the activity completed vs. your threshold. For example, an FTI of 100% would indicate that you worked at your threshold for the duration of the activity.

Efficiency Factor

We define the efficiency factor (EF) of a session as the ratio of your external (e.g., speed or power) to internal (e.g., heart rate) load ratio.

Aerobic Decoupling

Aerobic decoupling is a ratio number indicative of the durability of your efficiency across a session. More specifically, the number is a simple ratio of your session’s first half EF to its last half, where lower numbers tend to represent higher levels of durability.

Workout Reserve (WR)

By analyzing your past training data over different time ranges we can estimate how closely you performed to your maximum during each moment of your session. A score of 100% means you were fresh and far away from your previous best performance at the exercise duration in question. Conversely, a score of 0% would indicate you reached the best performance for the duration indicated. In essence, your WR serves as an indicator of your internal battery level throughout the specified duration of your workout.

Note that for the highest level of accuracy, you need to include a variety of maximum efforts over the entire spectrum of exercise durations on display. Don’t worry, if you follow our training plans this is ensured. Note that the WR marker is modelled in a non-linear fashion, just like the rating of perceived exertion (RPE) scale you may be more familiar with. Thus, emptying your batteries from 30% down to 20% is much easier than going from 20 to 10%. You can see your WR under the ‘Analysis / Session Chart’ tab.

minimum Workout Reserve (mWR)

The lowest value of your WR achieved during each training session plays a prominent role in our system, which is why we show it separately. A negative value means that you exceeded your previous best performance for the exercise duration indicated by the WR chart.

Quartic Mean Power (MP⁴)

Quartic Mean Power (MP⁴) is a power averaging method, measured in Watts, used to equilibrate for variable riding conditions (i.e., periods of high and low power output). The MP⁴ weighs periods of hard riding, such as with surges in pace, as higher compared to the condition of simply averaging the power over the same duration. This results in a more accurate depiction of the power requirements in a given duration and resultant training load.

Fitness

Fitness can be defined as the accumulation of, and adaptation to, training stress, over a long period of time. This broadly can be considered as your capacity to perform (i.e., how fit you are). Athletica uses a modified version of the original Banister et al. (1975) paper^[1] to make this calculation.

Form

Form (or freshness), refers to how much relief you have from training stress. Form is considered the inverse of the fatigue term. Athletica uses a modified version of the original Banister et al. (1975) paper to make this calculation.

Fatigue

Fatigue is the accumulation of training stress over a short period of time. For example, perform a large training session (high stress) relative to the daily amount of training you are used to having, and naturally, you will feel fatigued. Athletica uses a modified version of the original Banister et al. (1975) paper to make this calculation.

‘Performance Potential’ chart

Your Performance Potential chart (Figure 2) amalgamates the concepts of training load, into levels of fitness, fatigue and form, and subsequently reveals the journey you are on towards optimizing your Performance Potential for the races you have entered. Simply put, Athletica prescribes a training load that maximizes fitness and minimizes fatigue (enhances form) just prior to the performance you declare you are targeting (A, B or C race). Your Athletica training program updates its recommendations on a daily basis depending upon what does or doesn't get completed in training.

Figure 2. Example chart of Athletica providing daily load prescriptions to control fatigue, maximize fitness and maximize form before your next key event.