A Case Study
Do wellness metrics predict illness - maybe!
Over the last week or so I've had (head) cold type symptoms which tested negative to COVID.
The evening of the 23rd May (the red arrow on the graph) I had either a bit of 'pursuiter's cough' or a mildly sore throat - training earlier that day had been ergo at threshold heart rate.
By the next morning though it was a definite sore throat, spreading to blocked sinuses by the 25th. I felt the worst the evening of the 26th.
The period of illness lasted until the 30th May (the pretty classic one week for a cold) although symptoms were very mild by the end.
Could I have seen this coming? The answer is 'yes', however it is only really visible in hindsight (orange circles).
- my resting HR was elevated the day before but then dropped on the 23rd - but not back to the level in the days before. It then remains elevated for the period of illness.
- my respiration rate was also elevated the day before before dropping on the 23rd - again, but not back to the level in the days before.
The Body Battery data is interesting (but not predictive). Personally, I do find the body battery data a good proxy for 'energy', mainly driven by sleep quality. During the period of illness the body battery struggles to 'charge', even though plenty of sleep hours - obviously not enough quality when faced with a virus. And the score of '5' on the 26th is the lowest I've ever had (and the day I felt the worst).
For those interested in training through a cold infection, the number one rule is to do nothing if you have any type of infection below the throat - which I didn't. Most of my training during the period of illness (marked by the yellow circle) was at LT1 which didn't feel impacted by being ill, except for the 26th (the worst day of symptoms).
UPDATE: A new study has identified that for COVID infections there is an increase in respiration rate (1 breath per minute) above the baseline, along with a 1 beat per minute in resting heart rate above the baseline in the two days before testing positive. https://bmjopen.bmj.com/content/12/6/e058274