Effects of Creatine Supplementation on Cognitive Measures and Markers of Acute Kidney Injury After Exercise in the Heat

NCT07472426 | Recruiting

• 1 other identifier: IRB-FY26-36
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn if one week of creatine monohydrate supplementation alters inflammation, markers of acute kidney injury (AKI) risk, and cognitive performance in active, young, healthy volunteers. The main questions it aims to answer are:

• Complete a baseline aerobic exercise test to measure VO2max
• Ingest 20 grams per day of creatine monohydrate or placebo (maltodextrin) for seven consecutive days
• Cycle for 90 minutes in a heated chamber (38 C, \~40% relative humidity), alternating low- and high-intensity exercise
• Self-collect urine before, after, and one-hour after exercise
• Self-insert a rectal thermistor to measure core temperature
• Complete cognitive tasks using the NIH toolbox before and after exercise to assess cognition
• Complete the other condition (placebo or creatine) at least 21 days later

Conditions

Acute Kidney Injury; Exertional Heat Illness

Keywords

acute kidney injury; creatine monohydrate; exertional heat stress; cognition

Outcome Measures

Primary Outcomes (1)

• Change in Urine Biomarker of Acute Kidney Injury Risk from Creatine Use Prior to Exercise in the Heat (The mathematical product of IGBFP7 and TIMP-2 [IGFBP7 x TIMP-2; NephroCheck®])

  Concentrations of both IGBFP7 and TIMP-2 will be measured in the urine. The mathematical product of these values (IGFBP7 x TIMP-2) will then be calculated and reported for each time point.

  Change in urinary IGBP7 x TIMP-2 from immediately before exercise in the heat to 1 hour after exercise in the heat.

Study Arms (2)

Creatine Monohydrate

EXPERIMENTAL

Participants will ingest 20 grams per day of creatine monohydrate for 7 days, then 1 day of 5 grams before the exertional heat trial.

Dietary Supplement: Creatine Monohydrate

Placebo (Maltodextrin)

PLACEBO COMPARATOR

Participants will ingest 20 grams per day of maltodextrin for 7 days, then 1 day of 5 grams before the exertional heat trial.

Dietary Supplement: Maltodextrin (Placebo)

Interventions

Creatine Monohydrate DIETARY_SUPPLEMENT

20 grams per day of creatine monohydrate for 7 days, followed by 1 day of 5 grams of supplementation.

Creatine Monohydrate

Maltodextrin (Placebo) DIETARY_SUPPLEMENT

Participants will ingest 20 grams per day for 7 days, followed by 1 day of 5 grams.

Placebo (Maltodextrin)

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age range: 18-45 years old
• Physical Activity Level: Classified as 'active' using the criteria of engaging in planned exercise at least 3x/week, for a minimum of 30 minutes per session, over the past 3 months
• Aerobic Fitness Level: Subjects must have an aerobic fitness classification of at least 'good' per American College of Sports Medicine (ACSM) criteria and assessed via maximal oxygen uptake test
• Health Status: Free of any known cardiovascular, metabolic, renal, or neurologic conditions.
• Physical Limitations: Indicates no physical limitations to cycling for \~ 90 minutes
• Supplementation: Reports no use of creatine within the past 4 weeks
• Recent Illness: Reports no presence of illness, vomiting, or diarrhea in the previous three days.

You may not qualify if:

• Known allergy to creatine or maltodextrin.
• History of adverse heat-related events (e.g., heat exhaustion, heat stroke, severe dehydration requiring medical intervention)
• Reports use of medications or supplements that may interfere with thermoregulation, heart rate, kidney injury or blood pressure responses during exercise (e.g. NSAID)

Sponsors & Collaborators

• University of Northern Iowa: lead

Study Sites (1)

Wellness and Recreation Center

Cedar Falls, Iowa, 50614, United States

RECRUITING

MeSH Terms

Conditions

Acute Kidney Injury; Heat Stress Disorders

Interventions

Creatine; maltodextrin

Condition Hierarchy (Ancestors)

Renal Insufficiency; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Wounds and Injuries

Intervention Hierarchy (Ancestors)

Guanidines; Amidines; Organic Chemicals; Amino Acids; Amino Acids, Peptides, and Proteins

Central Study Contacts

Assistant Professor, PhD

CONTACT

5635137807; jonathan.specht@uni.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: March 6, 2026
• First Posted: March 16, 2026
• Study Start: March 12, 2026
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): May 1, 2027
• Last Updated: March 16, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)