Effect of Exercise and Heat Stress on Acute Cardiometabolic Adaptations in Healthy Young Adults

NCT06872762 | Recruiting

• 1 other identifier: 2224584
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

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

Keywords

exercise; heat strain; glucose tolerance test; arterial compliance

Outcome Measures

Primary Outcomes (1)

• Glucose tolerance

  Glucose to insulin concentration ratio in serum.

  2 hours after intervention complete

Secondary Outcomes (2)

• Arterial compliance

  2 hours after intervention complete

• Plasma volume expansion

  24 hours after intervention

Study Arms (3)

Exercise

EXPERIMENTAL

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

Behavioral: Exercise; Behavioral: Heat strain

Heat strain

EXPERIMENTAL

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

Behavioral: Exercise; Behavioral: Heat strain

Control

PLACEBO COMPARATOR

Resting control for 90 minutes. Not allowed to exercise.

Behavioral: Exercise; Behavioral: Heat strain

Interventions

Exercise BEHAVIORAL

Exercise for 90 minutes (cycling) while minimizing thermal strain

Control; Exercise; Heat strain

Heat strain BEHAVIORAL

Exercise for 90 minutes (cycling) while maximizing thermal strain

Control; Exercise; Heat strain

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• regularly physically active as determined via ParQ+

You may not qualify if:

• 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

Sponsors & Collaborators

• Northern Arizona University: lead

Study Sites (1)

Northern Arizona University

Flagstaff, Arizona, 86011, United States

RECRUITING

MeSH Terms

Conditions

Motor Activity

Interventions

Exercise

Condition Hierarchy (Ancestors)

Behavior

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Central Study Contacts

Travis Gibbons, PhD

CONTACT

928-523-4002; travis.gibbons@nau.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: INVESTIGATOR
• Masking Details: Researchers will be masked to data during analysis.
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: Random order, repeated measures, cross-over

Study Record Dates

• First Submitted: February 24, 2025
• First Posted: March 12, 2025
• Study Start: March 1, 2025
• Primary Completion: December 31, 2025
• Study Completion (Estimated): May 21, 2026
• Last Updated: March 12, 2025

Record last verified: 2025-02

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)