Validation of Heat Stress Limit Values for the Athletic Performance

NCT06084494 | Completed

• 1 other identifier: VEN 99 -11
• Study Type: interventional
• Target: 6
• Locations: 1 country
• Sites: 1

Brief Summary

Three male and three female semi-professional athletes, ranging in age from 22 to 27, participated in a study that was done at Lund University in Sweden to examine their physiological responses. The temperature and relative humidity were adjusted at 40 degrees Celsius for hot, dry conditions and 31 degrees Celsius for hot, wet conditions, respectively. The participants were instructed to engage in physical activity on a treadmill within the chamber for 70 minutes, or until participants were able to continue their exercise without difficulty within the allotted period. Participants were instructed to walk (5 kph) and run (8 kph). Participants pulse rate, breathing rate, oxygen consumption, and subjective reactions were all recorded. On the basis of the Wet Bulb Globe Temperature (WBGT), a heat stress index, the American College of Sports Medicine has made certain suggestions. The technique used to determine the temperature on a Celsius scale took into account the influences of relative humidity, air temperature, wind, and direct sunlight radiation. The American College of Sports Medicine advises delaying athletic competition when the WBGT is above 28 degrees. In the climate control chamber, the trials were carried out in high-risk circumstances (28 degrees Celsius WBGT). According to the study's findings, exercise is influenced by weather, and as air temperature rises, so do the intensity of exertion and thermal feeling.

Conditions

Physiological Stress; Heat Stress; Sports Injury; Heat Stress, Exertional

Keywords

Heat Stress; Physiological Responses; WBGT; PHS

Outcome Measures

Primary Outcomes (4)

• Physiological Response

  Rate of change of skin temperature (Tsk) of semi-professional athletes during walking 5km/hr and Jogging 8km/hr for 70 minutes in hot wet (Ta 40 C \& 70% RH) and hot dry (Ta 31C \& 20% RH) test conditions.

  70 minutes

• Physiological Response

  Rate of change of core body temperature (Tcore) of semi-professional athletes during walking 5km/hr and Jogging 8km/hr for 70 minutes in hot wet (Ta 40 C \& 70% RH) and hot dry (Ta 31 C \& 20% RH) test conditions.

  70 minutes

• Physiological Response

  Rate of change of Heart Rate (HR bpm) of semi-professional athletes during walking 5km/hr and Jogging 8km/hr for 70 minutes in hot wet (Ta 40 C \& 70% RH) and hot dry (Ta 31 C \& 20% RH) test conditions.

  70 minutes

• Physiological Response

  Consumption of oxygen (VO2 Max ml/min/kg) of semi-professional athletes during walking 5km/hr and Jogging 8km/hr for 70 minutes in hot wet (Ta 40 C \& 70% RH) and hot dry (Ta 31 C \& 20% RH) test conditions.

  70 minutes

Secondary Outcomes (2)

• Gender-Based Physiological Responses

  70 minutes

• Heat Stress Indices

  70 minutes

Study Arms (4)

Test Condition 1

EXPERIMENTAL

Variable Test Condition 1 WBGT 28 °C Clothing High Visibility Air Temperature 40 °C RH % 20 % Vapor Pressure 2.3 kPa Walking Speed 5 km/h Time 70 min

Diagnostic Test: analytical determination and interpretation of heat stress using calculation of the Predicted Heat Strain and Wet Bulb Globe Temperature

Test Condition 2

EXPERIMENTAL

Variable Test Condition 2 WBGT 28 °C Clothing High Visibility Air Temperature 40 °C RH % 20 % Vapor Pressure 2.3 kPa Walking Speed 8 km/h Time 70 min

Diagnostic Test: analytical determination and interpretation of heat stress using calculation of the Predicted Heat Strain and Wet Bulb Globe Temperature

Test Condition 3

EXPERIMENTAL

Variable Test Condition 3 WBGT 28 °C Clothing High Visibility Air Temperature 31 °C RH % 70 % Vapor Pressure 3.1 kPa Walking Speed 5 km/h Time 70 min

Diagnostic Test: analytical determination and interpretation of heat stress using calculation of the Predicted Heat Strain and Wet Bulb Globe Temperature

Test Condition 4

EXPERIMENTAL

Variable Test Condition 4 WBGT 28 °C Clothing High Visibility Air Temperature 31 °C RH % 70 % Vapor Pressure 3.1 kPa Walking Speed 8 km/h Time 70 min

Diagnostic Test: analytical determination and interpretation of heat stress using calculation of the Predicted Heat Strain and Wet Bulb Globe Temperature

Interventions

analytical determination and interpretation of heat stress using calculation of the Predicted Heat Strain and Wet Bulb Globe Temperature DIAGNOSTIC_TEST

The temperature inside the climatic chamber was set at 40 C and 31 C at a relative humidity of 20 % and 70 % respectively to count for a WBGT level of 28 C. The subject does walk at 5 km/h and jog at 8 km/h under these conditions for up to 70 minutes. The test includes the measurement of the height and weight of the subjects, heart rate, oxygen consumption, body weight loss (sweat evaporation), skin temperature, and core body temperature under hot environmental conditions. Subjective responses will also be recorded. WBGT was recorded after every ten minutes by heat stress meter and Bruel Kjaer.

Test Condition 1; Test Condition 2; Test Condition 3; Test Condition 4

Eligibility Criteria

• Age: 22 Years - 27 Years
• Gender Eligibility Details: Six semiprofessional athletes including three males and three females with a mean age of (24.7 ± 2.1 years) and a body surface area mean of (1.8 ± 0.2 m2) participated in this study.
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Semiprofessional aged 22-27 years of both genders.
• Body surface area between 1.5 to 2.5 m2
• Semiprofessional participating in regional competition level, receive monetary compensation for their sports participation, participating in sports activity in the last six year, and skill level.
• Semiprofessional demonstrating a higher level of skill and performance than recreational or amateur participants .

You may not qualify if:

• Subjects should not have any known heart disease or circulatory disorder.
• No known respiratory disease or heat allergy.
• No habitual smoker or drug user.

Sponsors & Collaborators

• University of the Punjab: lead
• Lund University: collaborator

Study Sites (1)

Department of Public Health, University of the Punjab

Lahore, Punjab Province, 54500, Pakistan

Location

MeSH Terms

Conditions

Heat Stress Disorders; Athletic Injuries

Condition Hierarchy (Ancestors)

Wounds and Injuries

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: FACTORIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical Trial Coordinator

Model Details: A wet Bulb Globe temperature (WBGT) level of 28 °C was simulated, and the temperature within the climatic chamber was set at 40 °C and 31 °C at relative humidity levels of 20% and 70%, respectively. Four test conditions were designed and subjects ran at 8 km/h and walked at 5 km/h for up to 70 minutes.

Study Record Dates

• First Submitted: August 2, 2023
• First Posted: October 16, 2023
• Study Start: October 21, 2012
• Primary Completion: February 1, 2013
• Study Completion: December 30, 2013
• Last Updated: March 30, 2025

Record last verified: 2025-03

Data Sharing

• IPD Sharing: Will not share

Locations

PA (1)