What data comes in
- ·Nightly Recharge (ANS charge score)
- ·Sleep (duration, stages: light/deep/REM)
- ·Heart rate (overnight average)
- ·Breathing rate
- ·Training sessions (duration, HR, sport type, calories)
What Polar is good at
Nightly Recharge is one of the better consumer recovery metrics — it’s derived from HRV analysis during the first hours of sleep, when autonomic recovery is most measurable. Polar devices are popular with runners and triathletes. Clean hardware, long battery life, and the ANS charge concept is scientifically grounded.
What it misses
How you actually feel this morning. Your training load from other sources (Strava, Wahoo). What’s on today’s plan. Whether yesterday’s session was easy or hard. Life context — stress, travel, motivation. The ANS charge tells you about overnight recovery, not about whether you should do today’s intervals.
How Rudder uses it
Polar feeds the Recovery channel— the same pipeline as Oura readiness and WHOOP recovery. Rudder looks at:
- ·ANS charge normalized against your personal baseline
- ·Sleep duration and stages normalized
- ·Breathing rate contributes to illness detection
When Polar says recovery is low but you feel great, Rudder detects and resolves the conflict using your personal history.
Best for
Runners and triathletes who train with Polar watches (Vantage, Grit X, Pacer Pro). Athletes who want Nightly Recharge to inform actual training decisions instead of just being a number on the watch.
Example decision
ANS charge is below usual. You feel fine. Today’s plan: tempo run. Sleep was 7.5h (adequate), breathing rate normal, no illness pattern. The low ANS charge is from yesterday’s hard session — your body is processing load, not declining.
Rudder recommends GO WITH LIMITS — cap at moderate effort. The ANS charge will recover by tomorrow.
How to connect
Polar connects directly via OAuth — no need to go through Intervals.icu as a bridge. Direct integration means your Nightly Recharge data syncs automatically.
Frequently asked
- What data does Rudder read from Polar?
- Nightly Recharge (HRV-derived recovery score), sleep data, and training sessions via Polar AccessLink. The Nightly Recharge score maps to Rudder's recovery channel.
- How do I connect Polar to Rudder?
- Go to Settings, tap Connect next to Polar, and authorize via the Polar AccessLink OAuth flow.
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