Heat Acclimation, Hand Cooling Efficacy, and Adaptation Maintenance.

NCT ID: NCT04053465

Last Updated: 2020-02-27

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 34 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2014-08-01
• Study Completion Date: 2015-03-31

Brief Summary

This study had three aims:

1. To determine the impact of consecutive days of exercise on thermoregulation and cardiovascular strain.

2. To determine the efficacy of a hand cooling device to cool individuals throughout a heat acclimation period.

3. To assess the maintenance of thermoregulatory and cardiovascular adaptations derived from heat acclimation during a 25-day intermittent exercise-heat exposure protocol.

Detailed Description

Participants completed 14 days of exercise heat acclimation in either a hot or cool environment, followed by a heat or cool exercise exposure every 5th day for 25 days. Cardiovascular, thermoregulatory, and perceptual strain were measured throughout exercise each day. Hydration assessment and stress response via blood biomarkers were measured before and after exercise. Aerobic capacity was measured before and after heat acclimation as well as after the intermittent exercise-heat exposure. Hand cooling was implemented periodically during exercise-heat stress visits to determine cooling efficacy before and after heat acclimation.

Conditions

Heat

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: OTHER
• Blinding Strategy: NONE

Study Groups

Exercise in heat group

Exercise in a hot environment

Group Type: EXPERIMENTAL

Heat acclimation

Intervention Type: OTHER

14 days of aerobic exercise in a hot environment

Exercise in cool group

Exercise in a cool environment

Group Type: PLACEBO_COMPARATOR

Exercise in a cool environment

Intervention Type: OTHER

14 days of aerobic exercise in a cool environment

Interventions

Heat acclimation

14 days of aerobic exercise in a hot environment

Intervention Type: OTHER

Exercise in a cool environment

14 days of aerobic exercise in a cool environment

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• no chronic health problems
• no previous history of exertional heat stroke within the past 3 years
• no history of cardiovascular, metabolic or respiratory disease
• no current musculoskeletal injury that limits physical activity

Exclusion Criteria

• women
• exercise less than once per week
• VO2max < 45 ml/kg/min

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

University of Connecticut

OTHER

Sponsor Role: lead

Responsible Party

Douglas J Casa

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Douglas J Casa, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Connecticut

References

Pryor RR, Pryor JL, Vandermark LW, Adams EL, Brodeur RM, Armstrong LE, Lee EC, Maresh CM, Casa DJ. Short term heat acclimation reduces heat strain during a first, but not second, consecutive exercise-heat exposure. J Sci Med Sport. 2021 Aug;24(8):768-773. doi: 10.1016/j.jsams.2021.03.020. Epub 2021 Apr 6.

Reference Type: DERIVED

PMID: 33846088 (View on PubMed)

Other Identifiers

H14-188

Identifier Type: -

Identifier Source: org_study_id