Renal Considerations in the Heat Stress Recommendations (Aim1)
Hot Weather; Adverse Effect, Kidney Dysfunction, Kidney Injury
About this trial
This is an interventional basic science trial for Hot Weather; Adverse Effect
Eligibility Criteria
Inclusion Criteria:
- Men and women
- 18-44 y old
- Body mass index ≤35.0 kg/m2
- Self-reported to be healthy.
Exclusion Criteria:
- Not within defined age range
- Estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m2
- Deemed highly active according to the physical activity questionnaire (i.e., >3500 MET*min/wk)
- Body mass index >35.0 kg/m2
- Current or history of any renal disease, heart disease, stroke, immune or autoimmune disease, and/or gastrointestinal disease/surgery
- Hypertension during screening (systolic blood pressure >139 or diastolic blood pressure >89)
- Using medications that blunt the physiological response to exercise (e.g., beta blockers)
- Prescription medication with a known side effect of impaired temperature regulation or fluid balance (e.g., diuretics)
- Positive pregnancy test at any time during the study or breast feeding
- Current tobacco or electronic cigarette use or consistent use within the last 2 years
- Inability to safely complete the peak oxygen uptake test
Sites / Locations
- School of Public HealthRecruiting
Arms of the Study
Arm 1
Arm 2
Experimental
Experimental
Fixed Work Rate
Fixed work-to-rest ratio
Participants will walk on a treadmill at 3 mph and the grade will be adjusted to elicit 430 W of metabolic heat production (the most common work intensity). This study will systematically examine the NIOSH recommendations for prescribing work-to-rest ratios with increasing environmental heat stress (defined as Wet Bulb Globe Temperature, WBGT) at this fixed rate of metabolic heat production on kidney function.
This study will systematically examine the NIOSH recommendations on changes in kidney function when the work-to-rest ratio is fixed at 30 min per hour (the most commonly prescribed work-to-rest ratio), but the rate of metabolic heat production and environmental heat stress differs (Figure 2). As described in Study 1, the appropriate rate of metabolic heat production will be elicited by having participants walk on a treadmill at 3 mph and the grade will be adjusted accordingly.