Knowledge

What Apple Watch measures as HRV at night

How Apple Watch records heart rate variability, how often it measures, and why the number moves from one night to the next.

SDNN vs. RMSSD: the difference in HRV

What SDNN and RMSSD each calculate, why Apple Health reports SDNN, and why values from the two metrics cannot be converted into each other.

How a recovery score works

How HRV, resting heart rate and sleep become a value from 0 to 100 – and why your own 30-day norm is what counts, not a reference table.

Adjusting training when recovery is low

On weak days cut sets first, then the weight – and only take a rest day last. How LeibFit ties volume and progression to your recovery.

Missing Apple Health data: trace the path

Find where missing health values stop: the wearable, its companion app, Apple Health or read access. Keep your Health history intact.

Missing HRV: no reading does not mean zero

Missing HRV is not low HRV. Check the record, date, source and permission before using the gap to explain your training readiness.

Understand multiple Apple Health sources

When watches, bands and apps write to Health, inspect source and time period to understand overlaps, duplicate workouts and changing trends.

Sleep score and recovery: why they differ

Good sleep and low recovery can appear together. Understand the different questions, inputs and time windows behind the two scores.

Readiness and training load are different

Readiness looks ahead; workload describes activity. Understand recovery, daily readiness and completed sessions without mixing up their roles.

Put sleep and training in context

Read sleep records, recovery and your planned session together. One score cannot settle an individual training decision on its own.

New wearable: compare the HRV trend carefully

A changed HRV trend after switching devices may reflect recording differences. Check the metric, time window and source before drawing conclusions.