Validation of Heat Stress Limit Values for the Athletic Performance
Condition: Physiological Stress; Heat Stress; Sports Injury; Heat Stress, Exertional
MeSH terms: Athletic Injuries; Heat Stress Disorders
Study type: Interventional

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.
    

Intervention name(s): analytical determination and interpretation of heat stress using calculation of the Predicted Heat Strain and Wet Bulb Globe Temperature
Intervention type(s): Diagnostic Test
Intervention description(s): 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.
Allocation: Randomized
Intervention model: Factorial Assignment
Intervention model description: 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.
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Heat Stress; Physiological Responses; WBGT; PHS