A Sex-Stratified Block-Randomized Controlled Trial of Bicarbonate-Rich Thermal Water Immersion on Cognitive Reliability and Post-Maximal Exercise Recovery in Adolescent Rowers During Field-Based Moderate-Altitude Training
| Registry | NCT07608913 |
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| Status | Completed |
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| Phase | Not applicable |
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| Study type | Interventional; randomized, parallel, masking: double, other |
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| Enrollment | 27 (Actual) |
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| Sponsor | Macao Polytechnic University (Other) |
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| Conditions | Altitude Training Adaptation, Cognitive Function, Cerebral Hemodynamics, Exercise Performance, Hydrotherapy, Balneotherapy, Hypoxia |
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| Interventions | Control Group：Natural Recovery, Hot water immersion group, hot spring immersion group (Behavioral) |
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| Dates | start 2026-01-25, primary completion 2026-02-26, completion 2026-03-08, first posted 2026-05-27, last updated 2026-08-04 |
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| Locations | 1 site in China |
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Related Papers Related Patents Related Grants Related Experts
All trials for Altitude Training Adaptation All trials for Cognitive Function All trials of Control Group：Natural Recovery All trials of Hot water immersion group
-Summary
This randomized controlled trial aims to investigate the effects of hot spring bath therapy on cognitive function recovery, cerebral hemodynamics, and athletic performance in athletes undergoing altitude training. Participants will be randomly assigned to either a hot spring intervention group, a hot water control group, or a blank control group. The hot spring intervention group receives hot spring baths (38°C, 20 minutes) combined with altitude training; the hot water control group receives hot water baths (38°C, 20 minutes) combined with altitude training; and the blank control group receives standard recovery procedures combined with altitude training. Primary outcome measures include cognitive performance assessments (Stroop test, psychomotor vigilance test) and cerebral hemodynamic indicators (functional near-infrared spectroscopy, transcranial Doppler ultrasound). Secondary outcomes included exercise capacity (maximal oxygen uptake, triathlon performance, 500-meter test), blood lactate, and hematological parameters (white blood cells, neutrophils, platelets). These findings may provide evidence for non-pharmacological interventions to enhance cognitive recovery and brain adaptation during altitude training.
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+Arms and interventions
| Arm | Type | Interventions | Description |
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| Natural Recovery Group | Active comparator | Behavioral: Control Group：Natural Recovery | Control group participants will undergo the same altitude training protocol (altitude 1600 meters) for 4 weeks. Participants underwent a 20-minute quiet seated rest at 16:00 on Tuesdays, Thursdays, and Saturdays, with ad libitum water consumption permitted and electronic devices prohibited. |
| Hot water immersion group | Active comparator | Behavioral: Hot water immersion group | The hot water immersion group will undergo a 4-week altitude training at 1600 meters above sea level. Subjects will receive a 20-minute hot water immersion (daily tap water, 38°C±0.5°C) in a standardized indoor hot spring facility. The immersion protocol includes partial-body immersion up to the xiphoid process (lower chest) for 20 minutes, followed by a 10-minute rest before leaving the facility. Three times per week. |
| Hot Spring Immersion Group | Experimental | Behavioral: hot spring immersion group | The hot spring immersion group will undergo a 4-week high-altitude training at an altitude of 1600 meters. Subjects will receive a 20-minute hot spring therapy (natural hot spring water, 38°C ± 0.5°C) in a standardized indoor hot spring facility. The immersion protocol includes partial-body immersion up to the xiphoid process (lower chest) for 20 minutes, performed three times per week, followed by a 10-minute rest before leaving the facility. |
- Control Group：Natural Recovery (Behavioral), also known as NR: Control group participants will undergo the same altitude training protocol (altitude 1600 meters) for 4 weeks. After each training session, participants will receive standard recovery procedures, including 20 minutes of passive rest in a thermoneutral environment (room temperature 24°C), supplemented with mild hydration and self-selected stretching. No hydrothermal intervention will be provided.
- Hot water immersion group (Behavioral), also known as HWI: The hot water immersion group will undergo a 4-week altitude training at 1600 meters above sea level. Subjects will receive a 20-minute hot water immersion (daily tap water, 38°C±1°C) in a standardized indoor hot spring facility. The immersion protocol includes whole-body immersion up to the neck for 20 minutes, followed by a 10-minute rest before leaving the facility. Three times per week.
- hot spring immersion group (Behavioral), also known as HSI: The hot spring immersion group will undergo a 4-week high-altitude training at an altitude of 1600 meters. Subjects will receive a 20-minute hot spring therapy (natural hot spring water, 38°C ± 1°C) in a standardized indoor hot spring facility. The immersion protocol includes whole-body immersion to the neck for 20 minutes, followed by a 10-minute rest before leaving the facility. Three times per week.
+Outcome measures
Primary outcomes
- Psychomotor Vigilance Test (PVT) [Baselines were measured at the formal start of the experiment, at night during the 2nd, 3rd, and 4th weeks (post-intervention) after ascending the plateau, and post-tests were conducted one week after descending the plateau.]: 5-minute PVT measuring sustained attention and psychomotor vigilance. Outcome variables: mean reciprocal response time (1/RT). Administered via standardized software on a tablet/computer. Unit: second.
- Stroop Test Performance [Baselines were measured at the formal start of the experiment, at night during the 2nd, 3rd, and 4th weeks (post-intervention) after ascending the plateau, and post-tests were conducted one week after descending the plateau.]: Computerized Stroop Color-Word Test measuring executive function and cognitive inhibition. Outcome variables: reaction time (ms). Administered in a quiet, temperature-controlled room (22-24°C). Unit: milliseconds (ms).
- Cerebral Oxygenation (fNIRS) [Baseline, Week 2, Week 5]: Changes in oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR) in the prefrontal cortex during cognitive tasks, measured by functional near-infrared spectroscopy (fNIRS) with a multichannel system. Outcome: relative changes in HbO and HbR concentrations. Unit: micromolar (μM).
- Cerebral Blood Flow Velocity (TCD) [Baseline, Week 2, Week 4]: Mean blood flow velocity in the middle cerebral artery (MCA) and anterior cerebral artery (ACA) measured by transcranial Doppler ultrasound (TCD) with 2MHz probe. Measurements taken in supine position after 10 minutes of rest. Outcome: mean velocity (cm/s). Unit: centimeters/second (cm/s).
Secondary outcomes
- Maximal Oxygen Uptake (VO2max) [Baseline, Week 5]: Maximal oxygen uptake measured using a portable metabolic analyzer during a graded exercise test on a rowing ergometer. Test protocol: incremental ramp test to exhaustion. Unit: mL/kg/min.
- 1000-Meter Running Test [Baseline, Week 3, Week4]: 1000-meter maximal effort running test on a standard 400m track or treadmill. Total completion time recorded. Unit: seconds (s).
- Peripheral Oxygen Saturation (SpO2) [one month.]: Resting peripheral oxygen saturation measured via fingertip pulse oximeter after 10 minutes of seated rest. Unit: percentage (%).
+Eligibility
Sex: All, ages: 11 Years to 17 Years, accepts healthy volunteers
Inclusion Criteria:
* Male or female aged 11-17 years- Regular endurance training (≥3 sessions/week) for ≥2 years
* No history of altitude exposure >2000m in the past 3 months
* No contraindications to hot water immersion (e.g., uncontrolled hypertension, severe cardiovascular disease, open wounds, pregnancy)
* Ability to provide written informed consent
* Willingness to abstain from other recovery modalities (e.g., massage, cryotherapy, compression garments) during the study period
* No color blindness or uncorrected visual impairment that would affect Stroop test performance
Exclusion Criteria:
* History of cardiovascular, respiratory, renal, or endocrine disorders
* Current use of medications affecting autonomic function or cognition (e.g., beta-blockers, anticholinergics, stimulants, sedatives)
* History of syncope, heat intolerance, or neurological disorders
* Acute musculoskeletal injury within the past 6 months- Regular use of sauna, hot tub, or spa within the past month- Pregnancy or breastfeeding (for female participants)
* Shift work or trans-meridian travel within 2 weeks prior to baseline assessment- Alcohol consumption >14 units/week or smoking
* History of traumatic brain injury, stroke, or psychiatric disorders
+Locations (1)
| Facility | City | Country | Status |
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| Field altitude-training camp, approximately 1600 m | Tengyue, Yunnan | China | |
+Publications
- Stanley J, Peake JM, Buchheit M. Consecutive days of cold water immersion: effects on cycling performance and heart rate variability. Eur J Appl Physiol. 2013 Feb;113(2):371-84. doi: 10.1007/s00421-012-2445-2. Epub 2012 Jul 3. PMID 22752345
- MacLeod CM. Half a century of research on the Stroop effect: an integrative review. Psychol Bull. 1991 Mar;109(2):163-203. doi: 10.1037/0033-2909.109.2.163. No abstract available. PMID 2034749
- Ando S, Hatamoto Y, Sudo M, Kiyonaga A, Tanaka H, Higaki Y. The effects of exercise under hypoxia on cognitive function. PLoS One. 2013 May 10;8(5):e63630. doi: 10.1371/journal.pone.0063630. Print 2013. PMID 23675496
- Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Intern Med. 2015 Apr;175(4):542-8. doi: 10.1001/jamainternmed.2014.8187. PMID 25705824
- Ohori T, Nozawa T, Ihori H, Shida T, Sobajima M, Matsuki A, Yasumura S, Inoue H. Effect of repeated sauna treatment on exercise tolerance and endothelial function in patients with chronic heart failure. Am J Cardiol. 2012 Jan 1;109(1):100-4. doi: 10.1016/j.amjcard.2011.08.014. Epub 2011 Sep 23. PMID 21944673
- Buchheit M, Simpson BM, Garvican-Lewis LA, Hammond K, Kley M, Schmidt WF, Aughey RJ, Soria R, Sargent C, Roach GD, Claros JC, Wachsmuth N, Gore CJ, Bourdon PC. Wellness, fatigue and physical performance acclimatisation to a 2-week soccer camp at 3600 m (ISA3600). Br J Sports Med. 2013 Dec;47 Suppl 1(Suppl 1):i100-6. doi: 10.1136/bjsports-2013-092749. PMID 24282195