Some users feel that their results (stress, recovery, or readiness) change significantly without matching their activities, fatigue, or subjective feelings. This is common and has several logical explanations. Elonga does not monitor only physical load. It evaluates the overall state of the autonomic nervous system (ANS), which reacts to a wide range of stimuli. Connections to activities are therefore not always direct or immediately obvious.

1. The ANS reacts not only to physical activity but also to psychological and internal processes

ANS activity is influenced by:

• psychological stress or tension,

• sleep quality and duration,

• nutrition and hydration,

• work, worries, emotions,

• recovery, fatigue, overtraining,

• early-stage illness or hormonal changes.

Many of these influences may not be consciously felt, but the ANS registers them earlier than you notice them.

Values may therefore change without a clear link to physical activity, yet still make perfect physiological sense.

2. HRV detects changes before they appear externally

A typical example is the onset of illness. HRV may drop or rise significantly before symptoms appear.

Your body is already responding, even though you feel completely normal.

This can make the results seem as if they are “jumping without reason,” even though the cause is already active in your system.

3. Not all activities have an immediate or direct effect

Sometimes:

• higher physical load leads to better results (correct timing + parasympathetic activation),

• a rest day produces a worse result (accumulated fatigue being processed),

• light activity improves recovery,

• the body reacts with delay, visible the following day.

ANS reactions are not linear or intuitive, they reflect complex physiology.

4. Short-term fluctuations are normal- the long-term trend matters

Day-to-day values can vary significantly. For the ANS, this is completely normal.

What matters is the trend, not individual spikes.

We recommend:

• consistent morning measurements,

• focusing on long-term development,

• avoiding conclusions based on one or two unexpected results.

5. Check the measurement conditions

Incorrect or non-standard measurements may create seemingly random results.

Make sure that:

• you measure only in the morning / after your main sleep,

• you stay still during the measurement,

• the sensor is positioned correctly,

• conditions are standardized,

• you do not perform repeated or back-to-back measurements.

Summary

Your results may appear to “jump” because:

• the ANS reacts to dozens of factors, not just physical activity,

• changes may appear before you consciously feel them,

• the body’s reactions are not always linear or immediate,

• psychological state strongly influences HRV,

• the long-term trend matters far more than individual values.

This is normal and not a sign of a measurement error.