Wellness scores and heart rate variability

Load tells you what went in. Wellness and HRV are two cheap ways of asking what came back out.

The morning check in

Athlivate uses the five questions most programs already ask: fatigue, nutrition, hydration by urine colour, energy and sleep quality, each on a 0 to 5 scale, plus a free text box for anything that hurts. It takes under 30 seconds. That brevity is not laziness. A questionnaire an athlete skips produces no data at all, and self report only works when compliance is high.

Every item is worded so that higher always means better. A 5 for fatigue means no fatigue. Anything written in the complaints box goes to the physio. Mixing directions is how monitoring systems end up quietly reporting the opposite of the truth.

Why we compare an athlete to themselves

Raw scores across a squad are close to meaningless. One 15 year old reports 4 on a good day and another never goes below 6. So each item is converted to a z score against that athlete's own rolling 28 day baseline.

The composite score is the mean of the five item z scores. A flag fires when the composite drops below -1.0, when any single item hits its worst possible value, or when the score falls more than 2 points from the day before. That last rule catches the sharp overnight change that a rolling average would smooth away.

Heart rate variability

HRV measures the variation in time between consecutive heartbeats. That variation is driven largely by parasympathetic, or vagal, activity. More variation usually means a nervous system in a recovered, adaptable state. Less variation often means the body is still dealing with something, whether that is training, illness, travel, or exam week.

The specific metric we use is RMSSD, the root mean square of successive differences between beats. RMSSD is skewed, so it gets a natural log transform, written lnRMSSD. Take it on waking, in the same position, before caffeine, before looking at a phone. Consistency of measurement matters more than the device.

Smallest worthwhile change

A single low reading means very little. Day to day HRV is genuinely noisy. So we compare a 7 day rolling mean against a 60 day baseline, and we only call it a change if it moves outside half a standard deviation of that baseline. That threshold is the smallest worthwhile change.