Postexercise Hot-Water Immersion on Exercise Performance in Hypoxia

Effect of Five Days of Postexercise Hot-Water Immersion on Exercise Performance in Hypoxia

The purpose of this study is to determine the effect of 5 days post-exercise hot water immersion on exercise performance at simulated altitude.

Study Overview

• Status: Not yet recruiting
• Conditions: Exercise Training; Heat Exposure
• Intervention / Treatment: Other: Post-Exercise Hot Water Immersion; Other: Control Group

Detailed Description

Human performance is compromised at altitude due to a lower partial pressure of oxygen and subsequent reductions in the convective transport of oxygen to tissue. Long-term acclimation to attitude incurs physiological adaptations that result in a near return to sea-level performance; however, the time required (~2 weeks) for such adaptations is often logistically challenging for athletes, military personnel or other individuals who reside at sea level. Recent research suggests that physiological acclimation to heat stress (i.e., heat acclimation) and altitude (i.e., hypoxia) share similar cellular adaptations, namely an up-regulation of Hypoxia-inducible factor 1 (HIF-1) and various heat shock proteins. Therefore, it is hypothesized that heat acclimation may provide physiological protection from reduced oxygen transport to the tissue and enhance performance at altitude. This cross-tolerance model is supported by traditional heat acclimation protocols (i.e., submaximal exercise in hot ambient temperature); however, it has not been tested with passive exposure to heat stress through post-exercise hot water immersion.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Geoffrey L Hartley, PhD; Phone Number: 705 845-3887; Email: geoffh@nipissingu.ca

Study Locations

• Canada
  • Ontario
    • North Bay, Ontario, Canada, P1B 8L7
      • Nipissing University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Physically active (minimum of 90 minutes of moderate-intensity exercise per week)

Exclusion Criteria:

• Cardiovascular disease
• resident of >1500 m above sea-level in the past year;
• history of fainting

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Post-Exercise Hot Water Immersion; Participants will cycle for 60 minutes at 50% of maximal oxygen uptake (VO2 max) followed by 30 minutes post-exercise hot water immersion (40oC) for 5 consecutive days.	Other: Post-Exercise Hot Water Immersion; Participants will cycle for 60 minutes at 50% of maximal oxygen uptake (VO2 max) followed by 30 minutes post-exercise hot water immersion (40oC) for 5 consecutive days.
Active Comparator: Control group; Participants will cycle for 60 minutes at 50% of maximal oxygen uptake (VO2 max); however, there will be not water immersion following exercise.	Other: Control Group; Participants will cycle for 60 minutes at 50% maximal oxygen uptake (VO2 max) for 5 consecutive days. There is no water immersion following the exercise.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time-Trial Performance in hypoxia conditions	Results of a 16 km time-trial test conducted at an fraction of inspired oxygen (FiO2) of 0.14	30 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pulse oxygen saturation during exercise	Capillary oxygen saturation measured on the earlobe throughout the time-trial tests using pulse oximetry.	30 minutes
Skin temperature during exercise	Skin temperature measured throughout the time trial-tests and exercise training intervention using temperature probes attached to the calf, thigh, chest and arm, from which weighted averages are calculated.	90 minutes
Core temperature during exercise	Core body temperature measured throughout the time-trial tests and exercise training interventions using a rectal temperature probe.	90 minutes
Heart Rate during exercise	Heart rate will be measured throughout the time trial tests and exercise training interventions using a wireless (Polar) heart rate chest strap.	90 minutes

Collaborators and Investigators

• Sponsor: Nipissing University
• Investigators: Principal Investigator: Geoffrey L Hartley, PhD, Nipissing University

Study record dates

Study Major Dates

• Study Start (Estimated): November 1, 2024
• Primary Completion (Estimated): October 31, 2025
• Study Completion (Estimated): October 31, 2025

Study Registration Dates

• First Submitted: October 30, 2024
• First Submitted That Met QC Criteria: November 1, 2024
• First Posted (Estimated): November 4, 2024

Study Record Updates

• Last Update Posted (Estimated): November 4, 2024
• Last Update Submitted That Met QC Criteria: November 1, 2024
• Last Verified: November 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Hypoxia
• Other Study ID Numbers: NUREB # 103807

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All of the individual participant data collected during the study, after de-identification, will be made publicly available using an online data repository.
• IPD Sharing Time Frame: Data will be made available immediately following publication with no end date.
• IPD Sharing Access Criteria: Any purpose.
• IPD Sharing Supporting Information Type: SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No