Four Heart Rate Variability Myths
Four HRV myths are Heart Rate Variability Is Bad, Stability Is Good, The Sympathetic Nervous System Plays a Major Role in Short-Term HRV,...
The BioSource Blog
BioSource Faculty Explain Core Concepts Based on
Peer-Reviewed Science
Fred Shaffer
- Aug 1
- 2 min
How Do You Know When HRV Training is Succeeding?
During slow-paced breathing between 4.6 to 6.5 bpm, you can examine your client's raw heart rate (HR) and respiration waveforms,...
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Fred Shaffer
- Jul 31
- 5 min
Slow-Paced Contraction Increases HRV
Slow-paced contraction (SPC) offers an alternative to slow-paced breathing, which is sometimes challenging (e.g., chronic pain) or...
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Fred Shaffer
- Jul 28
- 3 min
Low-Frequency Power and Coherence Index HRV Biofeedback Training Success
The low-frequency (LF) band (0.04-0.15 Hz) is affected by breathing from ~3-9 bpm (Task Force, 1996). The baroreflex system’s resonance...
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Fred Shaffer
- Jul 28
- 3 min
What is the RMSSD and Why is it Important to HRV Biofeedback?
The RMSSD is the root mean square of successive differences between normal heartbeats. Let's unpack this. We obtain the RMSSD by first...
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Fred Shaffer
- Jul 27
- 2 min
When Should You Not Use PPG Sensors to Measure HRV?
The electrocardiograph (ECG) and photoplethysmograph (PPG) are two methods of detecting heart rate (HR) and heart rate variability (HRV)....
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Fred Shaffer
- Jul 26
- 1 min
How HRV Biofeedback Increases RSA
Respiratory sinus arrhythmia (RSA) is the speeding and slowing of the heart across each breathing cycle. RSA is the primary and entirely...
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Fred Shaffer
- Jul 26
- 2 min
Faster Heart Rates Lower HRV and Increase Dementia Risk
Heart rate (HR) is important because a high rate can reduce heart rate variability (HRV), the changes in the time intervals between...
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