The Impact of Wearing the Hijab on Whole-body Heat Loss During Exercise-heat Stress

NCT07174180 | Recruiting

• 1 other identifier: HEPRU-2025-08-A
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

The hijab (headscarf and cloak) is a Muslim dress, which covers the head, neck and chest, and conceals the female hair, leaving the face uncovered. It is worn by Muslim women worldwide including young Muslim women engaging in sports and exercise. As with any clothing worn on the body, the hijab can impact heat dissipation during exercise, potentially leading to increased body temperature and discomfort, especially in warmer environments. However, the extent to which the hijab may restrict heat loss remains unclear. This study aims to assess dry and evaporative heat exchange in young women performing moderate-intensity intermittent exercise in dry heat conditions (40°C, 15% relative humidity).

Conditions

Heat Stress; Temperature Change, Body

Keywords

Core temperature; Exercise; Females; Garment; Heat strain; Thermoregulation; Hot weather

Outcome Measures

Primary Outcomes (14)

• Evaporative heat loss at end exercise

  Evaporative heat loss as assessed using a direct air calorimeter

  End of the 60-min intermittent exercise bout

• Dry heat loss at end exercise

  Dry heat loss as assessed using a direct air calorimeter

  End of the 60-min intermittent exercise bout

• Total heat loss at end exercise

  Total heat loss as assessed using a direct air calorimeter

  End of the 60-min intermittent exercise bout

• Body heat storage

  Heat stored in the body for each of the exercise bouts

  End of the 60-min intermittent exercise bout

• Change in body heat content

  Body heat content measured at the end of intermittent exercise

  End of the 60-min intermittent exercise bout

• Core temperature

  Rectal temperature during final 5 minutes of each of the exercise bouts

  End of the 60-min intermittent exercise bout

• Mean skin temperature

  Mean skin temperature during final 5 minutes of each of the exercise bouts

  End of the 60-min intermittent exercise bout

• Relative change in core temperature at end exercise

  Relative increase in core temperature for each 30-minute exercise bout

  End of the 60-min intermittent exercise bout

• Relative change in mean skin temperature at end exercise

  Relative change in mean skin temperature for each 30-minute exercise bout

  End of the 60-min intermittent exercise bout

• Heart rate

  Heart rate during final 5 minutes of each of the exercise bouts

  End of the 60-min intermittent exercise bout

• Rating of perceived exertion

  Perceived exertion assessed via a self-report questionnaire upon verbal prompting (scale is as follows: 6: indicating the participant is not exerting themselves at all with 20 indicating participant is exerting themselves maximally)

  End of the 60-min intermittent exercise bout

• Thermal sensation A

  Thermal sensation assessed via a self-report questionnaire upon verbal prompting (scale is as follows: 7-point scale; -3 indicating the participant is cold to +3 indicating the participant is hot)

  End of the 60-min intermittent exercise bout

• Thermal sensation B

  Thermal sensation assessed via a self-report questionnaire upon verbal prompting (scale is as follows: 7-point scale; 0 indicating the participant is neutral to 7 indicating the participant is extremely hot)

  End of the 60-min intermittent exercise bout

• Thirst sensation

  Thirst sensation assessed via a self-report questionnaire upon verbal prompting (scale is as follows: 9-point scale; 1 indicating the participant is not thirsty at all to 9 indicating the participant is very, very thirsty)

  End of the 60-min intermittent exercise bout

Study Arms (2)

No hijab

EXPERIMENTAL

Participants rest in a thermoneutral resting condition for 30-min (baseline resting) while wearing a cotton t-shirt and shorts, after which they enter a chamber regulated at 40°C where they perform an intermittent exercise bout consisting of two, 30-min moderate-intensity exercise bouts (fixed rate of heat production of 200 W/m2), with each exercise bout separated by a 15 min rest break and a 60-min recovery following the second exercise bout.

Other: Exercise-heat stress with no hijab

Hijab

EXPERIMENTAL

Participants rest in a thermoneutral resting condition for 30-min (baseline resting) while wearing a hijab over cotton t-shir and shorts, after which they enter a chamber regulated at 40°C where they perform an intermittent exercise bout consisting of two, 30-min moderate-intensity exercise bouts (fixed rate of heat production of 200 W/m2), with each exercise bout separated by a 15 min rest break and a 60-min recovery following the second exercise bout.

Other: Exercise-heat stress with a hijab

Interventions

Exercise-heat stress with no hijab OTHER

Participants perform exercise in the heat with no hijab

No hijab

Exercise-heat stress with a hijab OTHER

Participants perform exercise in the heat with a hijab

Hijab

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• healthy young female (18-35 years)
• non smoking
• English or French speaking
• ability to provide informed consent

You may not qualify if:

• claustrophobia
• engaged in endurance training
• acute or chronic illness
• sedentary (not engaged in any form of physical activity)
• physical restriction limiting physical activity

Sponsors & Collaborators

• University of Ottawa: lead

Study Sites (1)

University of Ottawa

Ottawa, Ontario, K1N6N5, Canada

RECRUITING

MeSH Terms

Conditions

Heat Stress Disorders; Body Temperature Changes; Motor Activity

Condition Hierarchy (Ancestors)

Wounds and Injuries; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Behavior

Study Officials

• Glen P Kenny, PhD

  University of Ottawa

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Glen P Kenny, PhD

CONTACT

6135625800; gkenny@uottawa.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Full Professor, University Research Chair

Study Record Dates

• First Submitted: August 15, 2025
• First Posted: September 15, 2025
• Study Start: June 13, 2025
• Primary Completion: October 31, 2025
• Study Completion: December 31, 2025
• Last Updated: September 15, 2025

Record last verified: 2025-09

Locations

CA (1)