Polar · Your reading
My Polar Nightly Recharge is poor. Should I train today?
Poor or very poor means you haven’t recovered well, so swap hard training for something easy. Compromised means slightly weakened recovery, usually from sleep, so train with the top trimmed. OK and above, train as planned.
What the status is made of.
Nightly Recharge combines two parts, each compared with your usual level over the past 28 days. ANS charge shows how well your autonomic nervous system calmed down, from heart rate, heart rate variability and breathing rate across roughly the first four hours of sleep. Heart rate has the most weight, breathing rate the least.
ANS charge runs from −10 to +10, with your usual level around zero; Polar’s white paper puts usual at −2 to +2. Sleep charge compares last night’s sleep score with your usual, on a scale from much below usual to much above usual.
Polar says ANS charge carries more weight. If it is much below your usual level, the status is red whatever your sleep was. You need three nights of wear, with more than 4 hours of sleep, before the first status.
What each status means for today.
| Score | Level | What to do today |
|---|---|---|
| Very poor | Very poor | Recover deliberately: a walk, easy mobility or genuine rest, chosen on purpose. If it repeats or you feel unwell, rest fully. |
| Poor | Poor | Switch the session: intervals become easy aerobic work, the heavy lift becomes mobility, and the hard day moves out two or three days. |
| Compromised | Compromised | Train, trimmed. Polar calls this slightly weakened recovery: for example, a sleep charge much below usual with ANS charge at usual. Keep the session, ease the intensity. |
| OK | OK | Train as planned. Polar counts OK as recovered well. |
| Good | Good | Train as planned. A good day for the session that matters most this week. |
| Very good | Very good | Train as planned. Take the hard session; don’t add extra just because the number allows it. |
Educational, not medical advice. With chest pain, a fever or feeling unwell, rest and see a doctor.
What the status can’t see.
Polar is clear that your body doesn’t separate stress from training, work, a late night or a party. A red morning after an obvious cause is noise. Several red mornings with no obvious cause is a pattern, and patterns decide.
The status can’t see a niggle, the race on Sunday or how you have eaten. Polar also notes that if you start while ill or very stressed, your usual level reflects an unusual time until it updates. Read ANS charge and sleep charge separately: a short night with a calm nervous system is a different day from the reverse.
Resting heart rate and HRV tell you most when read as trends against your own baseline, which is how Nightly Recharge is built. px reads your Nightly Recharge every morning alongside your sleep, HRV, resting heart rate and calendar, and sizes the day from all of it, telling you why.
Questions
What does compromised mean on Polar Nightly Recharge?
It is the yellow status: slightly weakened recovery. Polar gives the example of a sleep charge much below usual while ANS charge is at your usual level or higher. A trimmed session usually fits.
Should I train when Nightly Recharge is poor?
Polar says the red statuses, poor and very poor, mean you have not recovered well, and its daily exercise tip tells you whether to train, train lightly or rest. Easy aerobic work or mobility is usually the right swap, with the hard session moved a few days.
What is a normal ANS charge?
Around zero. The scale runs from −10 to +10 and Polar’s white paper puts your usual level at roughly −2 to +2, set from your past 28 days.
Why am I not getting a Nightly Recharge status?
Polar needs three consecutive nights of successful sleep measurement, more than 4 hours of sleep, and continuous heart rate tracking switched on. A loose strap or very restless sleep can also stop it.
px reads your Polar Nightly Recharge every morning.
Alongside your sleep, HRV, resting heart rate and calendar, so the day is sized from all of it, not one number. You get the plan and the reason.