Predicting Responses to Exhausting, Prolonged, And Repeated Exercise Demands (PREPARED) for Heat

January 22, 2026 updated by: Riana Pryor, State University of New York at Buffalo
The overall goal of this project is to identify a work/rest cycle that allows for faster mission completion needed in emergency situations, compared to current Army heat guidance, while mitigating heat strain and neuromuscular fatigue. This project will determine the trade-off between faster mission completion and risk of heat strain and physical performance decrements. Completion of this project will allow military leaders to make informed decisions by understanding the impact of their choices on the magnitude of physical performance decrements and expected heat casualties, setting up hot weather missions for success.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
24

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • New York
      • Buffalo, New York, United States, 14214
        • Recruiting
        • Center for Research and Education in Special Environments
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Healthy individuals
  • Physically active

Exclusion Criteria:

  • History of cardiovascular, metabolic (such as clinical thyroid disease), respiratory, neural, or renal disease
  • Hypertensive (systolic blood pressure > 139 mmHg, diastolic blood pressure > 89 mmHg) or tachycardic (heart rate > 100 bpm) during the screening visit
  • Taking medications or supplements known to effect physiologic responses to exercise or thermoregulation (e.g., beta blockers, omega-3 fatty acids, statins, aspirin)
  • Tobacco or nicotine use currently or in the past six months
  • Musculoskeletal injury expected to impact exercise in the protocol
  • A positive pregnancy test at any point in the study
  • Study physician discretion based on any other medical condition or medication
  • Inability to understand or follow instructions or the protocol
  • Gastrointestinal disease or previous surgery prohibiting core temperature capsule use. Participants with a contraindication can opt to insert the pill rectally as a suppository.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: 30/30 work/rest cycle first
Participants will first complete the 30/30 work/rest cycle, and then complete the other three conditions in a randomized fashion
Other: 30/30 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 30 minutes of work followed by 30 minutes of rest.
Other: 30/20 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 30 minutes of work followed by 20 minutes of rest.
Other: 40/30 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 40 minutes of work followed by 30 minutes of rest.
Other: 20/12 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 20 minutes of work followed by 12 minutes of rest.
Experimental: 30/20 work/rest cycle first
Participants will first complete the 30/20 work/rest cycle, and then complete the other three conditions in a randomized fashion
Other: 30/30 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 30 minutes of work followed by 30 minutes of rest.
Other: 30/20 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 30 minutes of work followed by 20 minutes of rest.
Other: 40/30 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 40 minutes of work followed by 30 minutes of rest.
Other: 20/12 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 20 minutes of work followed by 12 minutes of rest.
Experimental: 40/30 work/rest cycle first
Participants will first complete the 40/30 work/rest cycle, and then complete the other three conditions in a randomized fashion
Other: 30/30 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 30 minutes of work followed by 30 minutes of rest.
Other: 30/20 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 30 minutes of work followed by 20 minutes of rest.
Other: 40/30 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 40 minutes of work followed by 30 minutes of rest.
Other: 20/12 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 20 minutes of work followed by 12 minutes of rest.
Experimental: 20/12 work/rest cycle first
Participants will first complete the 20/12 work/rest cycle, and then complete the other three conditions in a randomized fashion
Other: 30/30 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 30 minutes of work followed by 30 minutes of rest.
Other: 30/20 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 30 minutes of work followed by 20 minutes of rest.
Other: 40/30 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 40 minutes of work followed by 30 minutes of rest.
Other: 20/12 work/rest cycle
Participants will walk on a treadmill while wearing a weighted backpack to a work/rest cycle of 20 minutes of work followed by 12 minutes of rest.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Core temperature
Time Frame: 180 minutes of work
Maximum gastrointestinal temperature reached during the work protocol
180 minutes of work
Isometric mid-thigh pull strength
Time Frame: 180 minutes of work
Maximum voluntary contraction strength assessed using a force plate
180 minutes of work

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Metabolic cost
Time Frame: 180 minutes of work
Collected expired air using a one-way mask will be analyzed using a metabolic cart to calculate metabolic heat production
180 minutes of work
Heart rate
Time Frame: 180 minutes of work
Maximum heart rate measured using a telemetry strap throughout the work protocol
180 minutes of work
Mean skin temperature
Time Frame: 180 minutes of work
Maximum skin temperature measured using buttons at four skin sites
180 minutes of work
Vastus lateralis electromyography
Time Frame: 180 minutes of work
Wireless electromyography electrodes placed lengthwise over the vastus lateralis muscle belly
180 minutes of work

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
State University of New York at Buffalo

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
United States Department of Defense

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Riana R Pryor, PhD, University at Buffalo

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 14, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 20, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 26, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 26, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 22, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • STUDY00007981
  • CDMRP-BA230031 (Other Grant/Funding Number: Department of Defense)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Aggregate results will be shared via publications and/or presentations. De-identified data may be shared and reviewed by the Department of Defense and as part of our Cooperative Research & Development Agreement with the United States Army Research Institute of Environmental Medicine.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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