NCT07307391

Exercise in Extreme Hot Weather Conditions

Physiological Responses in Semi-professional Athletes: a Comparison of the Effects of Hot Weather Conditions

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 6 (actual)
• Sponsor: University of Valladolid · Academic / Other
• Sex: All
• Age: 18 Years – 50 Years
• Healthy volunteers: Accepted

Summary

Background: Core body temperature increases in hot climates due to exercise workload, disrupting heat gain and loss of balance. The human thermoregulatory system regulates core body temperature through factors such as metabolic heat production, air temperature, humidity, and clothing. The study investigates physiological thermoregulatory responses in semiprofessional athletes during walking and jogging in different climatic conditions. Methods: A factorial experimental interventional design was used to evaluate different physical activity (low (L)=5 km/h and high (H)=8 km/h) and climatic conditions within the Thermal Environment Laboratory at Lund University, Sweden. The temperature within the climatic chamber was set at 40°C and 31°C, with a relative humidity of 20% and 70%, (hot dry (HD) and hot humid (HW), respectively, to account for a 28°C WBGT. The study used independent T-tests, ANOVA and simple linear regression models to analyse the physiological responses of semiprofessional athletes under different test conditions, comparing gender differences.

Conditions

• Heat Acclimation and Thermotolerance
• Heat Effect

Interventions

Type	Name	Description
OTHER	hot wet high (HWH)	Air Temperature (ºC) 30.6±1.2 Relative Humidity (%) 68.6±1.3 Vapour Pressure (kPa) 1011±1.1 Bruel and Kjear (WBGT ºC) 27.3±0.8 Heat Stress (WBGT ºC) 27.8±0.8 Air Velocity (m/s) 0.45±0.19
OTHER	hot dry high (HDH)	Relative Humidity (%) 39.7±0.3 Vapor Pressure (kPa) 29.0±1.2 Bruel and Kjear (WBGT ºC) 1007.9± 6.4 Heat Stress (WBGT ºC) 28.9±0.6 Air Velocity (m/s) 28.4±0.3
OTHER	Experimental: hot dry low (HWL)	Relative Humidity (%) 31.1±0.1 Vapor Pressure (kPa )67.1±1.0 Bruel and Kjear (WBGT ºC)1005.7±8.0 Heat Stress (WBGT ºC) 27.4±0.6 Air Velocity (m/s) 27.9±0.3
OTHER	Experimental: hot wet low (HWL)	Relative Humidity (%) 39.8±0.1 Vapor Pressure (kPa) 26.4±0.4 Bruel and Kjear (WBGT ºC) 1004.7±10.7 Heat Stress (WBGT ºC) 28.3±0.3 Air Velocity (m/s) 27.7±0.1

Timeline

• Start date: 2025-07-07
• Primary completion: 2025-12-10
• Completion: 2025-12-12
• First posted: 2025-12-29
• Last updated: 2025-12-31

Locations

1 site across 1 country: Spain