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Effects of Bicarbonate Spring Water Immersion on Cognitive Reliability and Post-Maximal Exercise Recovery in Adolescent Rowers During Altitude Training: A Sex-Stratified Three-Arm Randomized Controlled Trial

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

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07608913
Enrollment
27
Registered
2026-05-27
Start date
2026-01-25
Completion date
2026-03-08
Last updated
2026-08-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Altitude Training Adaptation, Balneotherapy, Cerebral Hemodynamics, Cognitive Function, Exercise Performance, Hydrotherapy, Hypoxia

Keywords

Altitude Sickness, Cognition, Cerebrovascular Circulation, Physical Performance, Hydrotherapy, Hot Springs

Brief 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.

Interventions

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.

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.

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.

Sponsors

Macao Polytechnic University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
DOUBLE (Subject, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
11 Years to 17 Years
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frameDescription
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 PerformanceBaselines 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 5Changes 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 4Mean 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

MeasureTime frameDescription
Maximal Oxygen Uptake (VO2max)Baseline, Week 5Maximal 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 TestBaseline, Week 3, Week41000-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 (%).

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 5, 2026