Tracked
Training Methodologies
8 min read
10/2/2026

HRV Explained: SDNN vs RMSSD

What heart rate variability measures, why SDNN and RMSSD give different numbers, why your own baseline matters more than anyone else's, and how Tracked labels the HRV it imports.

hrv
recovery
health sync
wearables
science
Loading content...

Ready to take your training to the next level?

Join 100,000+ athletes already using Tracked. Free forever, no ads, no hidden fees.

Available on iOS and Android. No credit card required.

Related articles