None listed
Conditions
Brief summary
The primary purpose is to investigate the effect of different core temperature targets on the acute and short term (24 h) response to passive heat stress when the thermal strain is matched between conditions. It is hypothesised that the moderate core temperature target (+1.0°C) will be more palatable and produce a similar 24 h response.
Interventions
This study will be a within-subjects semi-randomised crossover comparing two target temperatures: +1.0°C or +1.7°C (from baseline), all with the duration of exposure adjusted to match the thermal impulse. Participants will undergo all conditions in a random order (except that +0°C will have to occur after, not necessarily directly, +1.7°C so the duration can be matched).
Core body temperature will be measured and monitored using rectal thermistors. Sessions will be directly supervised by an ex
This study will be a within-subjects semi-randomised crossover comparing two target temperatures: +1.0°C or +1.7°C (from baseline), all with the duration of exposure adjusted to match the thermal impulse. Participants will undergo all conditions in a random order (except that +0°C will have to occur after, not necessarily directly, +1.7°C so the duration can be matched). Core body temperature will be measured and monitored using rectal thermistors. Sessions will be directly supervised by an experienced exercise physiologist. For each condition, participants will sit in a hot (40°C) water until their core temperature has increased by either +1.0°C or +1.7°C from baseline, where they will then adjust their depth in the water to maintain this core temperature. These exposures will last between 60-120 min, with the duration adjusted to match the thermal impulse between conditions. Each condition will be completed once, with at least one week separating them. These sessions will be completed at the University of Otago.
Sponsors
University of Otago
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Prevention
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
Being between 18 and 70 years old, be of either sex or any gender, not have any pre-existing conditions (e.g. injuries, any known cardiovascular/metabolic/respiratory disease) that increase risk during the tests, including meeting the requirements for the current Physical Activity Readiness Questionnaire (PAR-Q+) and Physical Fitness Questionnaire, be unacclimatised to the heat, be of any fitness or physical activity level.
Exclusion criteria
Any acute or chronic illnesses (e.g., diabetes, severe asthma, cardiovascular disease), Any injuries or consume medications that may impair ability to exercise in a hot environment (esp. diuretics or other cardiovascular-related medications), Any respiratory illness or recent (< 3 weeks) febrile illness. Having recently experienced moderate heat exposure (e.g. 30°C air temperature holiday in the last month) or regular heat exposure (e.g. 2 hours per week sauna/spa bathing within the previous 5 weeks). If so, the individual would be asked to forgo use and or wait until they have been home for at least 5 weeks before participating.
Outcome results
None listed