Effect of Aging and Aerobic Fitness Level on Heat Dissipation in Neutral Conditions
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Risk of Heat Stress
- Sponsor
- Petros Dinas
- Enrollment
- 431
- Locations
- 2
- Primary Endpoint
- Change from baseline axillary temperature
- Status
- Completed
- Last Updated
- 6 years ago
Overview
Brief Summary
In the context of global aging, the health risk factors associated with exercising or working in the heat for aging population are exacerbated by the rising in global surface temperatures. The purpose of this investigation is to determine at what age the heat loss decrements occur and to examine if aerobic fitness level can affect the heat loss capacity in neutral environmental conditions.
Detailed Description
All trials were conducted to indoor gyms with the same environmental temperature and relative humidity, 26 - 30oC and 40-50% respectively, to ensure no difference in body temperature were due to the external thermal stress. The participants were instructed to refrain from intense exercise as well as alcohol and caffeine consumption for 24 hours prior to experimental trial and to had a light meal 2h before their arrival. Upon arrival, participants would have to wear running shoes, light and short running shorts and light cotton socks. Participants received comprehensive instructions about the shuttle run test and the whole process of measurements. Firstly participants answered the International Physical Activity Questionnaire (IPAQ). Thereafter, anthropometrics data (weight and height) were evaluated as well as the body temperature in external ear canal and axillary. All participants followed five minutes warming up and then performed to 20 m shuttle run test until their volitional limit. Once the participants could no longer run, the test was over and the number of laps was recorded. After the end of the shuttle run, were evaluated the body temperature and the weight of each participants. No fluids consumptions were permitted until the second weighing. They were weighed twice, at baseline and at the end of the running test with a precision weight scale (Kern DE 150K2D, KERN \& SOHN GmbH, Balingen, Germany). Environmental data including air temperature and relative humidity were measured continuously using a portable weather station (LCD Digital Temperature \& Humidity Meter HTC-1). The weather station was placed 1 meter above the ground according to the manufacturer's guidelines.
Investigators
Petros Dinas
Senior Researcher in human physiology
University of Thessaly
Eligibility Criteria
Inclusion Criteria
- •Healthy children and adults
Exclusion Criteria
- •Diagnosed chronic medical condition;
- •Symptoms of acute illness;
- •Recent (past 4 weeks) usage of medications known to affect the circulatory system, the thyroid, the pituitary function, or the metabolic status
Outcomes
Primary Outcomes
Change from baseline axillary temperature
Time Frame: Change from baseline to the end of study completion (a shuttle run test), an average of 15 minutes
Axillary temperature was recorded twice, at baseline and at the end of the shuttle run test, using the electronic digital thermometer (EcoTemp, OMRON, Japan)
Change from baseline body weight
Time Frame: Change from baseline to the end of study completion (a shuttle run test), an average of 15 minutes
Weight was recorded twice, at baseline and at the end of the shuttle run test, using a precision weight scale (Kern DE 150K2D, KERN \& SOHN GmbH, Balingen, Germany
Aerobic fitness level
Time Frame: Through study completion (a shuttle run test), an average of 15 minutes
Aerobic fitness level was defined by peak oxygen uptake (VO2peak). VO2peak was determined by a 20m shuttle run test. The number of the last announced stage and the equivalent maximal speed from participants' performance were used for its VO2peak estimation
Physical activity levels
Time Frame: Once before the shuttle run test
Physical activity of the subject in a usual week was recorded via International Physical Activity Questionnaire. Scores include steps/day and METs/week, with no lower and upper limit
Change from baseline whole Body Sweat Rate
Time Frame: Change from baseline to the end of study completion (a shuttle run test), an average of 15 minutes
Whole Body Sweat Rate was determined by the difference of the pre-test and post-test weight of the participants
Change from baseline ear canal temperature
Time Frame: Change from baseline to the end of study completion (a shuttle run test), an average of 15 minutes
Ear canal temperature was recorded twice, at baseline and at the end of the shuttle run test (three times each at the left ear and recorded the mean value), using ear thermometer (IR100, MicrolifeSwitzerland)
Air temperature
Time Frame: Up to 30 minutes, during a one complete shuttle run test
Air temperature was measured continuously using a portable weather station (LCD Digital Temperature \& Humidity Meter HTC-1placed) 1 meter above the ground according to the manufacturer's guidelines
Relative humidity
Time Frame: Up to 30 minutes, during a one complete shuttle run test
Relative humidity was measured continuously using a portable weather station (LCD Digital Temperature \& Humidity Meter HTC-1) placed 1 meter above the ground according to the manufacturer's guidelines