Validation of Heat Stress Limit Values for the Athletic Performance

NCT ID: NCT06084494

Last Updated: 2025-03-30

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 6 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2012-10-21
• Study Completion Date: 2013-12-30

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.

Detailed Description

Methodology Experimental research design Study Duration 6 months Study Centres Thermal Environment Laboratory, Department of Design Sciences, Faculty of Engineering (LTH), Lund University Main Objectives Objective 1: To examine the physiological responses (skin temperature, core body temperature, body temperature, heart rate, and oxygen uptake) of semi-professional athletes during physical activity in different climatic conditions (hot wet and hot dry) Objective 2: To compare the effects of physical activity intensity (5 km/hr and 8 km/hr) on the physiological responses of semi-professional athletes under varying climatic conditions.

Objective 3: To investigate the influence of gender on the physiological responses of semi-professional athletes during physical activity in different climatic conditions.

Objective 4: To assess the suitability of the Physiological Heat Strain (PHS) and Wet Bulb Globe Temperature (WBGT) index for evaluating heat stress in sports settings based on the findings from semi-professional athletes.

No. of Participants 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.

Main Eligibility Criteria Key factors to consider when defining semiprofessionals include participation in regional competition level, receiving monetary compensation for their sports participation, participating in sports activity in the last six years, and skill level. These athletes typically demonstrate a higher level of skill and performance than recreational or amateur participants.

Conditions

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: FACTORIAL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

Test Condition 1

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

Group Type: EXPERIMENTAL

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

Intervention Type: 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 2

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

Group Type: EXPERIMENTAL

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

Intervention Type: 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 3

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

Group Type: EXPERIMENTAL

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

Intervention Type: 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 4

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

Group Type: EXPERIMENTAL

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

Intervention Type: 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.

Interventions

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

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.

Intervention Type: DIAGNOSTIC_TEST

Eligibility Criteria

Inclusion Criteria

• 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 .

Exclusion Criteria

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

• Minimum Eligible Age: 22 Years
• Maximum Eligible Age: 27 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Lund University

OTHER

Sponsor Role: collaborator

University of the Punjab

OTHER

Sponsor Role: lead

Responsible Party

Muhammad Salman Butt

Clinical Trial Coordinator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Department of Public Health, University of the Punjab

Lahore, Punjab Province, Pakistan

Countries

Pakistan

Provided Documents

Document Type: Study Protocol, Statistical Analysis Plan, and Informed Consent Form

View Document

Other Identifiers

VEN 99 -11

Identifier Type: -

Identifier Source: org_study_id