Prefrontal Hemodynamics and Working Memory After Exhaustive Aquatic Exercise

NCT07837661 | Completed

• 1 other identifier: 3784
• Study Type: interventional
• Target: 22
• Locations: 1 country
• Sites: 1

Brief Summary

This study compared prefrontal cortex hemodynamics and working memory performance following exhaustive aquatic exercise between endurance athletes and physically active individuals. Twenty-two healthy male participants aged 18-30 years, including 10 endurance athletes and 12 physically active controls, completed an incremental stepping exercise to exhaustion during head-out water immersion. The exercise was performed on a 20-cm step at xiphoid-level water depth, with cadence beginning at 18 steps/min and increasing by 2 steps/min every 30 seconds. Approximately 5 minutes after exercise, participants completed a seated 2-back working memory task while prefrontal cortex hemodynamic responses were assessed using functional near-infrared spectroscopy (fNIRS). Cognitive performance and prefrontal hemodynamic responses were compared between the two groups.

Conditions

Healthy Participants

Keywords

Functional Near-Infrared Spectroscopy; Prefrontal Cortex; Working Memory; 2-Back Task; Aquatic Exercise; Cerebral Hemodynamics

Outcome Measures

Primary Outcomes (5)

• Prefrontal Oxygenated Hemoglobin (HbO) During the 2-Back Task

  Whole-prefrontal oxygenated hemoglobin (HbO) was assessed using functional near-infrared spectroscopy (fNIRS) during the post-exercise 2-back task. HbO represents a baseline-referenced relative concentration change referenced to the 30-s post-exercise pre-task resting baseline and averaged across the five 2-back blocks.

  During the 2-back task beginning 5 minutes after exercise cessation

• Prefrontal Deoxygenated Hemoglobin (HbR) During the 2-Back Task

  Whole-prefrontal deoxygenated hemoglobin (HbR) was assessed using functional near-infrared spectroscopy (fNIRS) during the post-exercise 2-back task. HbR represents a baseline-referenced relative concentration change referenced to the 30-s post-exercise pre-task resting baseline and averaged across the five 2-back blocks.

  During the 2-back task beginning 5 minutes after exercise cessation

• Correct Responses During the 2-Back Task

  Number of correct responses (hits) to target trials during the 2-back working memory task, pooled across five blocks.

  During the 2-back task beginning 5 minutes after exercise cessation

• Incorrect Responses During the 2-Back Task

  Number of incorrect responses (false alarms) to non-target trials during the 2-back working memory task, pooled across five blocks.

  During the 2-back task beginning 5 minutes after exercise cessation

• Reaction Time for Correct Responses During the 2-Back Task

  Reaction time, in seconds, for correct responses (hits) during the 2-back working memory task, pooled across five blocks.

  During the 2-back task beginning 5 minutes after exercise cessation

Secondary Outcomes (1)

• Prefrontal Total Hemoglobin (HbT) During the 2-Back Task

  During the 2-back task beginning 5 minutes after exercise cessation

Study Arms (2)

Endurance Athletes

EXPERIMENTAL

Endurance athletes completed an incremental exhaustive aquatic stepping exercise protocol, followed approximately 5 minutes later by a seated 2-back working memory task with prefrontal fNIRS assessment.

Other: Incremental Exhaustive Aquatic Stepping Exercise

Physically Active Controls

EXPERIMENTAL

Physically active controls completed the same incremental exhaustive aquatic stepping exercise protocol, followed approximately 5 minutes later by a seated 2-back working memory task with prefrontal fNIRS assessment.

Other: Incremental Exhaustive Aquatic Stepping Exercise

Interventions

Incremental Exhaustive Aquatic Stepping Exercise OTHER

Participants performed stepping exercise on a 20-cm step during head-out water immersion at approximately xiphoid depth and approximately 30 °C water temperature. The protocol began at 18 steps/min, with cadence increasing by 2 steps/min every 30 seconds, and continued until exhaustion.

Endurance Athletes; Physically Active Controls

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy males aged 18-30 years.
• Endurance athletes or physically active individuals according to the study's predefined group criteria.
• Able to perform the aquatic stepping exercise protocol and complete the 2-back working memory task.
• Provided written informed consent to participate.

You may not qualify if:

• Presence of cardiovascular, pulmonary, neurological, metabolic, musculoskeletal, or psychiatric conditions that could affect exercise performance or cognitive assessment.
• Use of medications or substances that could influence cognitive function, cardiovascular responses, or exercise tolerance.
• Inability to safely perform the aquatic exercise protocol or complete the study procedures.

Sponsors & Collaborators

• Manisa Celal Bayar University: lead

Study Sites (1)

Manisa Celal Bayar University, Faculty of Sport Sciences, PERFORMS Laboratory

Manisa, 45040, Turkey (Türkiye)

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants were classified as endurance athletes or physically active controls based on their pre-existing training status. Both groups completed the same incremental exhaustive aquatic stepping exercise protocol; participants were not assigned to groups by the investigators.

Study Record Dates

• First Submitted: September 18, 2026
• First Posted: September 23, 2026
• Study Start: February 1, 2026
• Primary Completion: June 12, 2026
• Study Completion: June 12, 2026
• Last Updated: September 25, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)