Recruiting

Exercise & Heat Stress

Sponsor:

Northern Arizona University

Code:

NCT06872762

Conditions

Exercise

Heat Strain

Control Condition

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Accepted

Interventions

Exercise

Heat strain

Study Details

Brief summary:

Life in space is completely void of physical and environmental stress. It is well known that living things need regular physical stress (e.g. exercise) to remain strong, functional and healthy. More and more research is showing that regular environmental stress, for example heat and hypoxia, can further improve physical health. Astronauts aboard the international space station (ISS) exercise for 1-2 hours every day to avoid physical deconditioning that would otherwise cause them to age rapidly in space. Although physical exercise is very effective in remedying this deconditioning, today's astronauts still have physiological changes that indicate accelerated aging. This is a cause for concern given NASA's priority to travel to mars within the next decade; a mission that will require at least double the duration in space for our astronauts. The investigators think that the complete absence of environmental stress, i.e., heat, may be contributing to the accelerated aging that occurs during spaceflight. Our study will assess the health effects of adding heat stress to exercise that could be performed in space by astronauts. The goal is to inform best practice for astronauts to avoid physical deconditioning during long-duration spaceflight. This information will also be relevant to life on earth as spaceflight is a model of inactivity here on earth. Therefore, the potential benefits of adding heat stress will likely translate to life in space and on earth.

Conditions

Exercise

Heat Strain

Control Condition

Study ID

NCT06872762

Start date

Mar 1, 2025

Status verified date

Feb, 2025

Completion date

May 21, 2026

Anticipated

Primary completion date

Dec 31, 2025

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Accepted

Inclusion Criteria:

-regularly physically active as determined via ParQ+

Exclusion Criteria:

  • smokers
  • bronchial asthma
  • chronic obstructive pulmonary disease
  • obese
  • alcoholism
  • requiring daily medications that may effect responses to exercise,
  • anti-arrhythmogenics
  • inhalers
  • history of cardiovascular, respiratory, neurological, skeletal muscle disease
  • irregular/absent menstrual cycle (females)
  • unexpected responses to pre-experimental exercise tests
  • previous diagnosis of heat stroke

Study Design

Enrollment

15 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: Exercise

Participants exercise for 90 minutes trying to remain cool with fans and limited clothing.

experimental: Heat strain

Participants exercise for 90 minutes wearing winter and rain clothes to develop heat strain.

placebo comparator: Control

Resting control for 90 minutes. Not allowed to exercise.

Interventions

Exercise

Exercise for 90 minutes (cycling) while minimizing thermal strain

Heat strain

Exercise for 90 minutes (cycling) while maximizing thermal strain

Primary outcome measure

  • Glucose tolerance [ Time Frame: 2 hours after intervention complete ]

Central Contacts and Locations

Central contacts

Locations

Northern Arizona University

Recruiting

Flagstaff, Arizona, United States, 86011

Contacts

More Information

Sponsor

Northern Arizona University

Last update posted

Mar 12, 2025

Last verified

Feb, 2025

Keywords

  • exercise
  • heat strain
  • glucose tolerance test
  • arterial compliance

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Northern Arizona University on 2025-03-12.