What affects Nick's energy?

2025-08-13 → 2026-07-26 first pass · exploratory

Nick has no record labelled "energy", so this page uses the two closest things he has:

His own rating. Each morning, in the check-in he kept in the Reflections app, he rated his readiness 1, 2 or 3, where 3 means most ready. It records how he felt, by his own account, on 323 mornings.
His Oura ring's readiness score, 0–100, which the ring calculates each morning from his body: heart rate variability, temperature and the night's sleep.

The two do not agree. Across 288 mornings with both, the correlation between them is -0.03, which is essentially none. So they are looked at separately.

A note on timing. Each morning's score is compared with what Nick did the day before, not the same day. A drink on Tuesday, and Tuesday night's bedtime and sleep, are compared with how ready he was on Wednesday morning.

His own rating

We checked 26 things he tracked, one at a time, against how he rated himself the next morning. Almost nothing moved it. These 4 were the only ones that showed anything:

The day before	Correlation	Days	Signal
Time in high stress (Oura)	-0.18	321	a lead
Sleep efficiency (Oura)	+0.15	286	weak, could be chance
Amount of sugary snacks	+0.17	224	weak, could be chance
Sleep score (Oura)	+0.13	288	weak, could be chance

A correlation runs from −1 to +1, and all of these are small. After allowing for having checked 26 things, only one survives: Time in high stress (Oura). More stressful days go with feeling a little less ready the next morning. The other 22 showed nothing, including caffeine (p=0.95), alcohol (p=0.23), steps (p=0.47), hours slept (p=0.89), weekends (p=1.00).

Oura readiness: behaviours only

Nick's Oura readiness averages 75. This section and the next use the 243 days where every measure below was recorded. Sleep measures are left out here, because Oura calculates readiness from them. Alcohol, leaving his comfort zone, and caffeine, looked at together:

The day before	Compares	Readiness next morning	Signal
Alcohol	a day he drank, against a day he didn't	-3.9 points	clear
Left comfort zone	a day he logged leaving his comfort zone, against one he didn't	-2.9 points	clear
Caffeine, per cup	each extra cup of coffee that day	-1.4 points	unclear

Together these explain about 10% of the day-to-day ups and downs in his Oura readiness.

Oura readiness: adding bedtime

The same three behaviours, plus what time he went to bed that night.

The day before	Compares	Readiness next morning	Signal
Alcohol	a day he drank, against a day he didn't	-3.2 points	clear
Left comfort zone	a day he logged leaving his comfort zone, against one he didn't	-2.5 points	clear
Caffeine, per cup	each extra cup of coffee that day	-0.3 points	unclear
Bedtime, per hour later	each hour later he went to bed that night	-2.1 points	clear

Now about 15% is explained.

What this says

The ring and Nick measure different things. What predicts one says little about the other.
His own rating barely responds to anything he tracks. The one lead is stress.
Oura readiness: alcohol lowers it by about 3.2 points, and leaving his comfort zone by about 2.5, even once bedtime is accounted for.
Caffeine seems to act through bedtime: -1.4 points per cup on its own, -0.3 once bedtime is included. Coffee days are later-bedtime days, and the later bedtime is what shows up in readiness.

For the multi-variate analysis (weighing several behaviours at once, so each one's effect is measured with the others held steady) click here

That analysis covers Oura readiness only. Nick's own rating had too little signal for it: only one thing stood out once we allowed for how many were checked, and only weakly, so there is nothing yet to weigh against anything else.