A dataset of heart rate variability and respiratory activity during paced and free breathing

Overview This dataset contains physiological recordings of respiratory activity and heart rate variability (RR intervals). The data were collected to investigate and analyze respiratory sinus arrhythmia (RSA). All files are provided in .xlsx, .csv, and .txt format to ensure broad interoperability and are optimized for analysis in software such as R, Python, or MATLAB. Version 1.1.2 update: Standardized all column headers across processed datasets to English; uncropped raw data time series (raw_data_RSA.xlsx); included supplementary breathing frequency metrics (breathing_frequency.xlsx). Incorporated an extended RSA metrics sheet (Porges–Bohrer amplitudes, spectral coherence, phase, and respiratory energy ratios) alongside a comprehensive Data Dictionary (Data_Dictionary.xlsx) Data Content The repository includes heart rate variability (HRV) and respiration data to map cardiorespiratory coupling. Heart rate variability data: Provided in both wide (RR_hrvb.csv) and long (RR_long_format.csv) format. It contains the time intervals between successive heartbeats (RR intervals), suitable for HRV analysis. HRV parameters (hrv_indexes.xlsx): Time and frequency domain indexes for each participant, session and breathing frequency. Furthermore, an RSA metrics sheet was incorporated. Respiration data in long format (resp_hrvb.txt): Provided in long format. Uncropped and unfiltered raw data (raw_data_RSA.xlsx): Continuous, unfiltered raw RR time series as directly exported from the acquisition server. Breathing frequency metrics (breathing_frequency.xlsx): Derived breathing frequency values (breaths per minute) calculated for each participant, session, and protocol step. Data dictionary: Dataset file, variable name(s), description, data type, unids, and valid range / coding. Column name conventions in the HRV wide format file: Column names begin by specifying the variable as RR (rr) and timestamps (time). The variable name is followed by the participant number and session. This is the original file downloaded from the server where the data is stored. Variables (column names) across the HRV long format file includes: participant_id: Unique identifier for each participant. session_id: Session number (from 1 to 6). rr: RR interval in milliseconds (ms). timestamps: Time of recording in seconds from start. protocol_step: Respiratory frequency from 1 to 10. output: Binary indicator where 1 represents paced breathing and 0 represents spontaneous breathing. Variables (column names) across the Respiration long format file includes: participant_id: Unique identifier for each participant. session_id: Session number (from 1 to 6). resp_amplitude: Signal amplitude in millivolts (this is directly the output of Sleepsense band). timestamps: Time of recording in seconds from start. protocol_step: Respiratory frequency from 1 to 10. output: Binary indicator where 1 represents paced breathing and 0 represents spontaneous breathing. Variables (column names) across the HRV indexes file includes: participant_id: Unique identifier for each participant. session_id: Session number (from 1 to 6). protocol_step: Respiratory frequency from 1 to 10. MeanHR mRR SDNN RMSSD pNN50 VLF_peak LF_peak HF_peak VLF_power LF_power HF_power VLF_norm LF_norm HF_norm LF_nu HF_nu LF_HF_ratio Total_power output: Binary indicator where 1 represents paced breathing and 0 represents spontaneous breathing. Variables (column names) across the HRV indexes file, RSA sheet includes: participant_id: Unique identifier assigned to each subject (e.g., 001 to 035). session_id: The optimal RF session number (ranging from 1 to 6). resp_freq: Target respiratory frequency (ranging from 4.5 to 6.5 breaths/min). RSA_index: RSA index computed with the Porges–Bohrer algorithm in ln(ms²) units. Cxy_rsa: Spectral coherence between RR and the respiratory signal at frequency Fpeak_rsa. ang_rsa: Phase of the cross-spectrum between RR and the respiratory signal at frequency Fpeak_rsa in degrees. %RSA(0.004-0.16Hz): Percentage of energy of the respiratory peak, within a bandwidth of 2 breaths/min (0.033 Hz), of the respiration signal relative to its total energy between 0.004 and 0.16 Hz. %RSA(0.004-0.4Hz): Percentage of energy of the respiratory peak, within a bandwidth of 2 breaths/min (0.033 Hz), of the RSA signal relative to its total energy between 0.004 and 0.4 Hz. Variables (column names) across the breathing_frequency.xlsx file include: participant_id: Unique identifier for each participant. session_id: Session number (from 1 to 6). resp_pct_6.5 to resp_pct_4.5: Percentage of target paced breathing compliance at each metronomic rate (6.5, 6.0, 5.5, 5.0, and 4.5 bpm). bb_6.5 to bb_4.5: Measured breathing frequency (breaths per minute, bpm) derived via time-domain breath-by-breath peak detection for each target rate. sdbb_6.5 to sdbb_4.5: Standard deviation of breath-by-breath respiratory rate (breaths per minute) during each target paced breathing step. FFT6.5 to FFT4.5: Peak respiratory frequency (bpm) calculated via spectral Fast Fourier Transform analysis for each target step. BW6.5 to BW4.5: Respiratory bandwidth metrics derived for each target breathing rate. Data acquisition The dataset includes 35 healthy participants, 16 men (average age = 30.5 ± 13.10 years) and 19 women (average age = 25.63 ± 7.26 years). The study consisted of six weekly sessions of optimal resonance frequency protocol. Each session comprised 20 minutes of continuous, synchronized recording of RR intervals and respiration.Each session began with two minutes of paced breathing guided by an audio metronome set at 6.5 breaths per minute (bpm). This phase was immediately followed by a period of spontaneous breathing, during which no metronome was displayed (free breathing). The sequence of paced and free breathing phases alternated throughout the session. During each subsequent paced breathing phase, the breathing rate was progressively reduced by 0.5 bpm compared to the previous one, until reaching a final paced breathing rate of 4.5 bpm.