Recruiting
Early Phase 1

Observational Study

Sponsor:

Penn State University

Code:

NCT04284397

Conditions

Aging

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Interventions

Low dose ASA

Control

Study Details

Brief summary:

This study evaluates critical environmental limits (temperature and humidity) above which older adults are unable to effectively thermoregulate. Participants will exercise in a series of different environmental conditions to identify combinations of temperature and humidity above which age-related physiological changes cause uncompensable heat stress, resulting in increased risk of heat illness.

Conditions

Aging

Study ID

NCT04284397

Start date

Dec 30, 2020

Status verified date

Jan, 2026

Completion date

Feb 27, 2027

Anticipated

Primary completion date

Feb 27, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Adults aged 18 and older (those 40+ years of age must be cleared by collaborating physician)
  • All premenopausal women will be eumenorrheic (by survey)
  • Asymptomatic and no signs/symptoms of disease according to the American College of Sports Medicine 10th edition Guidelines for Exercise Testing and Prescription

Exclusion Criteria:

  • Medications that affect thermoregulatory or cardiovascular responses to exercise
  • Any contraindications to low intensity physical activity on the Physical Activity Readiness Questionnaire
  • Any mobility restrictions that interfere with low intensity physical activity
  • Pregnant or planning to become pregnant in the next 12 months
  • Prior diagnosis of cancer, cardiovascular disease, diabetes, or metabolic syndrome
  • Illegal/recreational drug use
  • History of Chron's disease, diverticulitis, or similar gastrointestinal disease
  • Abnormal resting or exercise electrocardiogram (ECG)

Study Design

Enrollment

190 participants

Anticipated

Allocation

Randomized

Intervention Model

Single group

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Critical Environmental Limits

Subjects will perform exercise at \~200-300W with ambient temperature or humidity increasing every 5 min throughout the trial until core temperature begins to rise.

experimental: Aspirin Supplementation

After a minimum of 7 days of daily, low-dose aspirin ingestion, older subjects will repeat critical environmental limits trials. As before, subjects will perform exercise at \~200-300W with ambient temperature or humidity increasing every 5 min throughout the trial until core temperature begins to rise.

Interventions

Low dose ASA

A sub-group of older adults will be re-tested after 7 days of treatment with low-dose aspirin.

Control

All participants will be tested with no treatment.

Primary outcome measure

  • Temperature and humidity limits for maintaining stable core temperature [ Time Frame: Through study completion, an average of 1 year. ]

Central Contacts and Locations

Central contacts

Lacy M Alexander, Ph.D.

8148671781lma191@psu.edu

Locations

Noll Laboratory

Recruiting

University Park, Pennsylvania, United States, 16802

Contacts

W. Larry Kenney, Ph.D.

814-863-1672w7k@psu.edu

S. Tony Wolf, Ph.D.

814-863-8557saw85@psu.edu

More Information

Sponsor

Penn State University

Last update posted

Jan 27, 2026

Last verified

Jan, 2026

Keywords

  • Aging
  • Thermoregulation
  • Heat stress

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Penn State University on 2026-01-27.