In my recent posts, I explored how the Area of Normal Functioning — ANF — can be applied beyond computer systems.
I started with sport-performance data, including SoccerMon athlete-monitoring data and longitudinal runner training logs. Those examples showed that ANF can describe an athlete’s normal training-load range, detect unusual weeks, identify shifts in the normal regime, and even suggest possible training cycles.
This time I wanted to test ANF on a different kind of human-performance dataset: not competitive sport, but clinical exercise and recovery monitoring.
For this experiment, I used the ATOPE+Breast dataset, which contains daily monitoring records for breast-cancer patients during a therapeutic exercise intervention. The uploaded records.csv file includes daily fields for patient ID, study day, training-session information, HRV metrics, wellness self-reports, sleep, and activity/steps. The available fields include lnrmssd, recovery, fatigue, distress, sleep_satisfaction, sleep_time, Fitbit sleep fields, and step/activity metrics.
This makes the dataset especially interesting for ANF. The goal here is not athletic performance. The goal is safer human adaptation: how a patient responds to exercise, recovery, sleep, fatigue, and treatment context over time.
Why this dataset is different
In runner or soccer data, the main question is often about performance:
- Is the athlete training inside a normal load range?
In clinical exercise data, the question is different:
- Is the patient recovering and adapting within their own normal functional range?
That makes ANF potentially useful as a patient-specific monitoring layer. It does not diagnose medical problems, and it should not replace clinical judgment. But it can help highlight when a patient’s daily recovery or physiological state moves away from their recent normal pattern.
For a first proof of concept, I selected one patient with a relatively long daily history and built ANF charts using rolling percentile boundaries.
The model used:
- rolling baseline from recent observations,
- CL = P50,
- UCL = P95,
- LCL = P05,
- gray band = ANF,
- orange points = outside the ANF,
- vertical markers = training-session days.
Chart 1 — LnRMSSD / HRV ANF
The first chart uses LnRMSSD.
LnRMSSD means the natural logarithm of RMSSD, a common heart-rate-variability metric. In practical terms, it is often used as an indicator of autonomic recovery or physiological readiness.
For ANF, this is important because it gives us a more objective physiological signal than self-reported wellness alone.
In this chart, the ANF band represents the patient’s recent normal range of HRV-based recovery. A day below the lower boundary may suggest that the patient’s physiological recovery is lower than usual. A sustained downward movement may indicate stress, fatigue, treatment burden, poor sleep, or another contextual factor.
Of course, one point should not be over-interpreted. Human physiology is noisy. The value of ANF is not in treating one daily value as a diagnosis, but in showing how the patient’s recovery pattern behaves relative to their own recent baseline.
Chart 2 — Recovery Risk Index ANF
he second chart uses a combined recovery-risk index.
This index summarizes the subjective side of recovery: perceived recovery, fatigue, distress, and sleep-related state. The dataset includes daily self-reported variables such as recovery, fatigue, distress, sleep_satisfaction, and sleep_time.
This chart is interesting because it represents the “human feeling” side of the same process. HRV may show physiological recovery, but subjective wellness may show how the patient actually feels.
In ANF terms, the recovery-risk chart asks:
Is the patient’s perceived recovery state still within their recent normal range?
Days above the upper boundary may suggest unusually elevated recovery risk — for example, higher fatigue, lower perceived recovery, poorer sleep, or higher distress. Again, ANF does not explain the cause by itself. It highlights the departure from the patient’s own recent normal state.
Why the combination matters
The most interesting part is not either chart alone, but the idea of comparing them.
A patient may have:
- normal HRV but poor subjective recovery,
- low HRV but normal self-reported recovery,
- both signals inside ANF,
- or both signals outside ANF.
That combination may be more useful than a single metric.
For example, if HRV drops below normal and the recovery-risk index rises above normal, that may be a stronger signal that the patient is under unusual strain. If only one signal changes, the interpretation may require more context.
This is very similar to the way I previously connected business-driver metrics with computer-system metrics. A single signal is useful, but two related ANFs can provide a better diagnostic picture.
From sport performance to human recovery
This example broadens the ANF idea.
In the runner dataset, ANF described normal weekly training load.
In SoccerMon, ANF described athlete load and wellness/readiness.
In ATOPE+Breast, ANF describes patient-specific recovery and adaptation during therapeutic exercise.
That is an important step.
It suggests that ANF may apply not only to computer systems and athletes, but also to broader human recovery and rehabilitation contexts.
The common question remains the same:
What is normal for this system, at this time, and when has that normal changed?
First conclusion
This is still an exploratory proof of concept, but it is a useful one.
The ATOPE+Breast dataset shows that ANF can be applied to daily human recovery data, combining physiological, subjective, sleep, activity, and training-session information.
For me, the main takeaway is:
ANF can help describe a patient-specific area of normal recovery and adaptation.
This should not be interpreted as medical diagnosis. Instead, it is a monitoring and interpretation framework that may help clinicians, coaches, researchers, or patients notice when daily recovery patterns move outside the recent normal range.
In the broader ANF research direction, this dataset provides an important bridge:
- from technical systems,
- to sport-performance systems,
- to clinical human adaptation and recovery.
That makes it a valuable addition to the future ANF paper.



