Chronic Exercise With Overdressing

NCT07099872 | Completed

• 1 other identifier: 24-26
• Study Type: interventional
• Target: 13
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to determine if five training sessions of exercise with overdressing can induce heat acclimation.

Conditions

Heat Acclimation and Thermotolerance

Keywords

Heat Acclimation; Heat Stress Test

Outcome Measures

Primary Outcomes (4)

• End-exercise Core Temperature

  End-exercise core temperature during heat stress test

  Through study completion, an average of 8 weeks

• Resting Core Temperature

  Core Temperature at Rest during Heat Stress Test

  Through study completion, an average of 8 weeks

• End-exercise heart rate

  Heart rate at end of heat stress test

  Through study completion, an average of 8 weeks

• End-exercise Mean Weighted Skin Temperature

  Mean weighted Skin temperature at end of heat stress test

  Through study completion, an average of 8 weeks

Secondary Outcomes (1)

• Urine Specific Gravity

  Through study completion, an average of 8 weeks

Study Arms (2)

Exercise with Overdressing

EXPERIMENTAL

5 days of standardized exercise with overdressing

Other: Overdressing

Exercise

ACTIVE COMPARATOR

5 days of standardized exercise wearing PT clothing

Other: Control

Interventions

Control OTHER

Wear normal attire (shorts/t-shirt) during exercise sessions in a gym-like environment.

Exercise

Overdressing OTHER

Wear standardized overdressing ensemble during exercise sessions in a gym-like environment.

Exercise with Overdressing

Eligibility Criteria

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

You may qualify if:

• Females must be premenopausal.
• Body mass index 18.5-33.0 kg m-2.
• In good health as determined by the Office of Medical Support \& Oversight (OMSO) General Medical Clearance.
• Performs aerobic exercise at least 2 times per week and capable of running 2 miles in under 17:00 (8:30 minute mile pace).
• Willing to abstain from exercise and alcoholic beverages for 24 hrs before each study visit.
• Willing to abstain from caffeine for 12 hrs prior to all study visits.
• Willing to abstain from food for 2 hrs prior to all study visits.
• Willing to abstain from nicotine/tobacco for at least 8 hrs prior to all study visits.
• Have supervisor approval if permanent party military or a federal employee at U.S. Army Natick Soldier System Center.

You may not qualify if:

• Frequent hot bath or sauna users (e.g., more than three times a week for the past month).
• Females who are pregnant or planning to become pregnant during the study.
• Taking dietary supplements, prescriptions, or over the counter medication, other than a contraceptive (unless approved by OMSO \& PI).
• Abnormal blood count during OMSO medical screening (For example: hemoglobin (Hb) outside of the typical normal values reported by LabCorp in accordance with OMSO (Normal \[Hb\] Males = 12.6-17.7 g/dL; Females = 11.1-15.9 g/dL) or hematocrit (Hct) outside of the normal ranges (Normal Hct Males = 37.5-51.0%; Females = 34.0-46.6%) levels, presence of abnormal blood chemicals (hemoglobin S or sickle cell traits).
• Any history of pulmonary, cardiovascular, or renal disease (unless approved by OMSO \& PI).
• Uncontrolled asthma.
• Current or recent respiratory tract or sinus infections (\< 2 weeks prior).
• History of heat stroke or orthostatic intolerance.
• Diagnosed and/or treated for fluid/electrolyte imbalance within the last 30 days.
• History of obstructive disease of the gastrointestinal tract including (but not limited to) diverticulosis, diverticulitis and inflammatory bowel disease, peptic ulcer disease, Crohn's disease, ulcerative colitis.
• Scheduled MRI during testing.
• Allergies to adhesives (e.g., medical tape).

Sponsors & Collaborators

• United States Army Research Institute of Environmental Medicine: lead

Study Sites (1)

US Army Research Institute of Environmental Medicine

Natick, Massachusetts, 01760, United States

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: FED
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 26, 2025
• First Posted: August 1, 2025
• Study Start: October 28, 2024
• Primary Completion: May 5, 2025
• Study Completion: May 5, 2025
• Last Updated: August 1, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)