SPECIAL ISSUE: Slow-Paced Contraction: An Evidence-Based Method for Increasing Heart Rate Variability

Abstract

Slow-paced muscle contraction (SPC) is an easily learned method for increasing heart rate variability (HRV). SPC provides an alternative to slow-paced breathing (SPB) in clinical and optimal performance applications. SPB can be challenging (e.g., chronic pain), anatomically impossible (e.g., phrenic nerve damage), or medically contraindicated (e.g., diabetes and kidney disease). SPC may be especially helpful for clients who breathe dysfunctionally or who cannot slow their breathing to the resonance frequency (RF) range. The RF is an individual’s unique stimulation rate that maximally increases HRV. Wrist-core-ankle SPC increases several HRV metrics more than only contracting the wrists and ankles. Preliminary evidence suggests that combining wrist-ankle SPC with SPB may increase HRV more than either method alone.