Nervous System Training May Support Running Recovery

At a women’s movement and education festival in Breinigsville, Pennsylvania, psychologist Erin Ayala demonstrated resonance frequency breathing, a method calibrated to the individual. A waist strap and finger sensor tracked breathing, pulse, blood oxygen and nervous-system activity. During the exercise, a five-count inhale and seven-count exhale coincided with reduced stress signals and greater parasympathetic activity—the system associated with rest, digestion and relaxation.

The technique is intended to raise heart rate variability, or HRV, relative to a person’s usual level. HRV reflects tiny differences, measured in milliseconds, between consecutive heartbeats and can indicate how the nervous system is balancing strain with recovery. Among healthy adults, the typical range spans 19 to 75 milliseconds, although personal levels differ with age, genetics, fitness and daily behavior. Genetics may explain 50 to 60 percent of that variation. Several small studies have connected this breathing practice with changes in HRV and blood-pressure regulation. In 2020, a small Journal of Human Kinetics study found a promising improvement in track athletes’ 5K performance after HRV biofeedback training.

For runners, the potential value lies in helping the body shift from fight-or-flight activity toward recovery and regulation. Slow, low breathing is central to the method; breathing forcefully or rapidly can instead increase arousal and cause lightheadedness, tingling or a racing heart. HRV can also be influenced by sleep, exercise, hydration, stress and alcohol. Wearables can estimate it during rest: Garmin collects overnight readings in five-minute segments, establishes a personal range over three weeks, and then updates that range using rolling seven-day averages.