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RecruitingNCT06475339Updated Jan 26, 2026

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

An interventional study of 30/30 work/rest cycle and 30/20 work/rest cycle in Hyperthermia and Fatigue; Heat, sponsored by State University of New York at Buffalo. Recruiting at 1 site in United States. Open to participants aged 18 Years to 39 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-26.

Sponsored by State University of New York at Buffalo · Not applicable, Interventional, and Prevention

Phase
Not applicable
Study type
Interventional
Enrollment
24
Allocation
Randomized
Ages
18 Years to 39 Years
Sex
All
01

Study summary

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.

02

Conditions studied

  • Hyperthermia
  • Fatigue; Heat
03

Who can participate

Ages eligible
18 Years to 39 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Healthy individuals
  • Physically active

Exclusion criteria

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.
04

Study design

Phase
Not applicable
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Crossover assignment
Masking
None (open label)
Enrollment
24 participants (estimated)

Study arms

  • 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 · Other: 30/20 work/rest cycle · Other: 40/30 work/rest cycle · Other: 20/12 work/rest cycle

  • 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 · Other: 30/20 work/rest cycle · Other: 40/30 work/rest cycle · Other: 20/12 work/rest cycle

  • 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 · Other: 30/20 work/rest cycle · Other: 40/30 work/rest cycle · Other: 20/12 work/rest cycle

  • 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 · Other: 30/20 work/rest cycle · Other: 40/30 work/rest cycle · Other: 20/12 work/rest cycle

Interventions

  • Other30/30 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.

  • Other30/20 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.

  • Other40/30 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.

  • Other20/12 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.

05

What researchers measure

Primary outcomes

  1. Core temperature

    Maximum gastrointestinal temperature reached during the work protocol

    Time frame: 180 minutes of work

  2. Isometric mid-thigh pull strength

    Maximum voluntary contraction strength assessed using a force plate

    Time frame: 180 minutes of work

Secondary outcomes

  1. Metabolic cost

    Collected expired air using a one-way mask will be analyzed using a metabolic cart to calculate metabolic heat production

    Time frame: 180 minutes of work

  2. Heart rate

    Maximum heart rate measured using a telemetry strap throughout the work protocol

    Time frame: 180 minutes of work

  3. Mean skin temperature

    Maximum skin temperature measured using buttons at four skin sites

    Time frame: 180 minutes of work

  4. Vastus lateralis electromyography

    Wireless electromyography electrodes placed lengthwise over the vastus lateralis muscle belly

    Time frame: 180 minutes of work

06

Study locations

1 of 1 sites recruiting
  • Center for Research and Education in Special Environments
    Buffalo, New York 14214, United States
    Recruiting
07

References and documents

Individual participant data

Plan to share: No — 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.

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT06475339
Lead sponsor
State University of New York at Buffalo
Collaborators
United States Department of Defense
Responsible party
Riana Pryor (Assistant Professor, State University of New York at Buffalo) — Principal investigator
First posted
Jun 26, 2024
Start date
Nov 1, 2024
Primary completion
Mar 2027 (estimated)
Completion
Mar 2027 (estimated)
Last update
Jan 26, 2026

Study contacts

Riana R Pryor, PhD
Contact
rpryor@buffalo.edu
7168295456
Riana R Pryor, PhD
principal investigator · University at Buffalo

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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