Schipper 2025 — HRV & Breathing Training in Golf (Master Thesis, DSHS Cologne)

What Was Investigated?

This master thesis at the German Sport University Cologne examined whether consciously controlled resonance frequency breathing (RFB) can influence heart rate variability (HRV) in golfers during putting — and whether this translates into improved accuracy under stress conditions. The study bridges two current research fields: HRV-based biofeedback and mental performance optimization in sports.

Methodology

28 recreational golfers participated in this experimental prospective randomized intervention study. Using a repeated measures design, each participant served as their own control. Subjects putted under two conditions: voluntary breathing (control condition) and prescribed RFB breathing frequency (4 seconds inhalation, 6 seconds exhalation). Auditory stimuli via headphones simulated a stress-like competitive situation.

HRV was measured using the Mindfield eSense Pulse — a validated device with 1-channel ECG and 500 Hz sampling rate that records inter-beat intervals (IBI) via a chest strap and transmits data via Bluetooth to the eSense App. Respiratory rate was simultaneously measured with the Mindfield eSense Respiration, which uses an abdominal belt to register the expansion and compression of abdominal breathing. Psychophysiological workload was additionally assessed using the NASA Task Load Index (NASA-TLX) questionnaire.

Results

Resonance frequency breathing produced significant changes in several HRV parameters in the intervention group compared to the control group:

• Heart rate: Significant reduction (p = 0.003)
• RR interval: Significant increase (p = 0.003)
• SDNN: Significant increase (p = 0.039)

The breathing rate of the intervention group was, as expected, significantly lower than in the control group, confirming successful implementation of the RFB protocol.

However, no statistically significant performance difference in putting results could be demonstrated — neither from two meters distance (p = 0.284) nor from four meters (p = 0.458). The NASA-TLX questionnaire showed significantly higher psychophysiological workload (p < 0.001) in the intervention group, suggesting that simultaneously performing breathing control and the putting task required additional cognitive resources.

Practical Significance

The study demonstrates that HRV can be significantly influenced through conscious reduction of breathing rate via RFB in the short term — an important finding for all application areas where HRV modulation is used as a stress management tool.

The author primarily attributes the absence of improved putting performance to the dual-task effect: simultaneously controlling breathing and executing the motor task overwhelmed participants’ cognitive capacities, which is supported by the elevated NASA-TLX scores. The brief familiarization phase with the RFB technique likely also played a role.

For practical applications, this means: longer-term RFB training that automates the breathing technique could make the positive HRV effects usable without the additional cognitive burden. The study also recommends individually adapted breathing patterns rather than a fixed 4:6 rhythm.

Furthermore, the thesis confirms the suitability of Mindfield eSense sensors for sports research — both the eSense Pulse for HRV recording under movement conditions and the eSense Respiration for real-time breathing rate monitoring.