A study to explore whether different temperatures of warm water footbaths have different effects on the cardiovascular system, the autonomic nervous system and the general well-being of healthy women.
This is a blinded, four-arm randomized controlled trial with crossover design to explore the effects of warm water footbaths with different water temperatures on cardiovascular stress, reaction of the autonomic nervous system and a feeling of comfort and warmth in healthy female volunteers. Cardiovascular and ANS measurements are performed continuously throughout the interventions and the participants rate their feelings of warmth, general well-being and the footbath-related comfort with questionnaires.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Enrollment
28
A ten-minute pre-intervention rest period followed by a 30-minute footbath with 16 l of warm water at a constant temperature of 38°C, followed by a ten-minute post-intervention rest period.
A ten-minute pre-intervention rest period followed by a 30-minute footbath with 16 l of warm water at a constant temperature of 40°C, followed by a ten-minute post-intervention rest period.
A ten-minute pre-intervention rest period followed by a 30-minute footbath with 16 l of warm water at a constant temperature of 42°C, followed by a ten-minute post-intervention rest period.
Arcim Institute
Filderstadt, Baden-Wurttemberg, Germany
Pressure Rate Product (PRP) at timepoint t5 (footbath minute 21-30)
Pressure Rate Product (PRP), calculated from systolic blood pressure (measured with the Mobil-O-Graph® PWA) and heart rate (measured with the Bittium Faros 360TM ECG recorder) at timepoint 5 (t5 = mean of the measurements recorded from minute 21 to minute 30 of the footbath).
Time frame: Timepoint 5 (t5 = mean of the measurements recorded from minute 21-30 of the 30-minute footbath)
Change in Pressure Rate Product (PRP) at timepoints t1 (minute 1-10 of the pre-intervention rest period), t3 (minute 1-10 of the footbath), t4 (minute 11-20 of the footbath), and t7 (minute 1-10 of the post-intervention rest period).
Pressure Rate Product (PRP), calculated from systolic blood pressure (measured with the Mobil-O-Graph® PWA) and heart rate (measured with the Bittium Faros 360TM ECG recorder) at timepoints t1 (t1 = mean of the measurements recorded from minute 1 to minute 10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1 to minute 10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11 to minute 20 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1 to minute 10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Heart rate variability (HRV) analysis: Change in SDNN
SDNN: Standard deviation of normal to normal (NN) intervals (ms) (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
A ten-minute pre-intervention rest period followed by a 30-minute footbath with 16 l of warm water. Water temperature starts at 38°C and is increased by 1°C every 6 minutes, resulting in 42°C after 30 minutes. The footbath is followed by a ten-minute post-intervention rest period.
Change in pNN50
pNN50: Percentage of successive NN intervals that differ from each other by more than 50 ms (%) (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in HF
HF: High frequency power band (0.15-0.40 Hz) (ms2) from frequency domain analysis (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in LF
LF: Low frequency power band (0.04-0.15 Hz) (ms2) from frequency domain analysis (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in LF/HF ratio
LF/HF ratio = ratio of two bands from frequency domain analysis: LF band (0.04-0.15 Hz), HF band (0.15-0.40 Hz) (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in VLF
VLF: Very low frequency power band (0.0033-0.04 Hz) (ms2) from frequency domain analysis (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Mean Heart Rate
Mean heart rate (bpm) (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in SD2/SD1 ratio
SD2/SD1 ratio, derived from Poincaré plot (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Stress Index
Stress Index (SI) according to Baevsky's formula SI = AMo/2Mo\*MxDMn (Mo = mode, AMo = mode amplitude, MxDMn = variation range of RR intervals) (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Respiration Rate
Respiration rate (1/min) (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Heart Rate/Respiration Rate ratio
Heart rate/respiration rate ratio (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in RMSSD
RMSSD: Root mean square of successive differences (ms) (Bittium Faros 360TM ECG recorder). Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Stiffness Index
Stiffness Index, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Perfusion Index
Perfusion Index, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Peak to Peak Time
Peak to Peak Time (PPT, ms), measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in SlopeInW1
SlopeInW1, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in SlopeInW2
SlopeInW2, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in SlopeInW3
SlopeInW3, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in SlopeInW4
SlopeInW4, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Reflection Index
Reflection Index, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in TimeTX
TimeTX (ms), measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in TimeTY
TimeTY (ms), measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in QuotTYTX
QuotTYTX, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in AreaAX
AreaAX, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in AreaAY
AreaAY, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in QuotAYAX
QuotAYAX, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in TimeTV
TimeTV (ms), measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in TimeTW
TimeTW (ms), measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in QuotTVTW
QuotTVTW, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in AreaAV
AreaAV, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in AreaAW
AreaAW, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in QuotAVAW
QuotAVAW, measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Oxygen Saturation
Oxygen saturation (SpO2, %), measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Pulse Transit Time
Pulse Transit Time (PTT, ms), measured with the Vitaguard® VG 3100 monitor, getemed, Germany. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Systolic Blood Pressure
Systolic Blood Pressure (mmHg), measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Diastolic Blood Pressure
Diastolic Blood Pressure (mmHg), measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Mean Arterial Pressure
Mean Arterial Pressure (mmHg), measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Pulse Pressure
Pulse Pressure (mmHg), measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Stroke Volume
Stroke Volume (ml), measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Cardiac Output
Cardiac Output (l/min), measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Peripheral Resistance
Peripheral Resistance, measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Cardiac Index
Cardiac Index, measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Augmentation Pressure
Augmentation Pressure (mmHg), measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Augmentation Index
Augmentation Index, measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in Pulse Wave Velocity
Pulse Wave Velocity (PWV, m/s), measured with the Mobil-O-Graph® PWA. Measurements analysed at timepoints t1 (t1 = mean of the measurements recorded from minute 1-10 of the pre-intervention rest period), t3 (t3 = mean of the measurements recorded from minute 1-10 of the footbath), t4 (t4 = mean of the measurements recorded from minute 11-20 of the footbath), t5 (t5 = mean of the measurements recorded from minute 21-30 of the footbath), and t7 (t7 = mean of the measurements recorded from minute 1-10 of the post-intervention rest period).
Time frame: Physiological parameters are measured continuously (Vitaguard® VG 3100, GETEMED; Bittium Faros 360TM) and every 2 min (Mobil-O-Graph® PWA) for a total duration of 50 min.
Change in warmth perception at the feet
Self-reported warmth perception at both feet, assessed with the "Herdecke warmth perception questionnaire" immediately before (timepoint 2, t2), immediately after (timepoint 6, t6) and 10 minutes following the footbath (timepoint 8, t8). Each item is scored 0-4 (0 = cold; 4 = hot), yielding a mean between 0 and 4.
Time frame: Immediately before (timepoint 2, t2), immediately after (timepoint 6, t6) and 10 minutes following the footbath (timepoint 8, t8) (length of footbath is up to 30 minutes).
Change in warmth perception at the hands
Self-reported warmth perception at both hands, assessed with the "Herdecke warmth perception questionnaire" immediately before (timepoint 2, t2), immediately after (timepoint 6, t6) and 10 minutes following the footbath (timepoint 8, t8). Each item is scored 0-4 (0 = cold; 4 = hot), yielding a mean between 0 and 4.
Time frame: Immediately before (timepoint 2, t2), immediately after (timepoint 6, t6) and 10 minutes following the footbath (timepoint 8, t8) (length of footbath is up to 30 minutes).
Change in warmth perception at the head
Self-reported warmth perception at the head, assessed with the "Herdecke warmth perception questionnaire" immediately before (timepoint 2, t2), immediately after (timepoint 6, t6) and 10 minutes following the footbath (timepoint 8, t8). Each item is scored 0-4 (0 = cold; 4 = hot), yielding a mean between 0 and 4.
Time frame: Immediately before (timepoint 2, t2), immediately after (timepoint 6, t6) and 10 minutes following the footbath (timepoint 8, t8) (length of footbath is up to 30 minutes).
Change in overall warmth perception
Self-reported overall warmth perception, assessed with the "Herdecke warmth perception questionnaire" immediately before (timepoint 2, t2), immediately after (timepoint 6, t6) and 10 minutes following the footbath (timepoint 8, t8). The item is scored 0-4 (0 = cold; 4 = hot).
Time frame: Immediately before (timepoint 2, t2), immediately after (timepoint 6, t6) and 10 minutes following the footbath (timepoint 8, t8) (length of footbath is up to 30 minutes).
Change in general well-being
Self-reported well-being, assessed with the "Basler Befindlichkeits-Skala" (Basel Mood Questionnaire, BBS) immediately before (t2), immediately after (t6) and 10 minutes following the footbath (t8) (BBS: 16 items; 7-point rating scale; higher values represent a better outcome).
Time frame: Immediately before (timepoint 2, t2), immediately after (timepoint 6, t6) and 10 minutes following the footbath (timepoint 8, t8) (length of footbath is up to 30 minutes).
Change in feeling of comfort during footbath
Self-reported footbath comfort, assessed with a 7-point face scale ranging from "very comfortable" (laughing face) to "very hard stress" (crying face).
Time frame: Immediately before the footbath (timepoint 2, t2), every 6 minutes during the 30-minute footbath, and 10 minutes following the footbath (timepoint 8, t8).