Acute heat stress and heat acclimation Not Applicable
Conditions
Interventions
The study consists of 19 visits spread over a 4-6 week period depending on the timing between visits. This includes four fitness test visits, three familiarisation exercise visits, nine heat acclimati
Time of the day: Any time of the day)
This visit will be used for consenting and screening and to determine their aerobic fitness. Upon arrival, the study will be fully explained to the participant he
women - 40 ml/kg/min), they will be scheduled for subsequent visits. If the aerobic fitness criterion is not met, they will not be eligible to continue taking part in the study.
Visits 2, 3 and 4 –
Time of the day: Any time of the day)
The purpose of the familiarisation visits is to get participants acquainted with the type of exercise that will follow during the rest of the study. They will be
Sponsors
University of Birmingham
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: 1. Men or women 2. Aged 18 – 45 years 3. Compliance: understands and is willing, able and likely to comply with all study procedures and restrictions 4. Consent: demonstrates an understanding of the study and willingness to participate as evidenced by voluntary written informed consent 5. In good general health with no previous history of cardiometabolic disease 6. Body mass index in the range 18.5 – 27.5 kg/m² 7. Aerobically trained (i.e., participates in endurance-based exercise [e.g. cycling, running, rowing] at least three times per week) 8. Aerobic fitness: VO2max >45 ml/kg/min (men), >40 ml/kg/min (women)
Exclusion criteria
Exclusion criteria: 1. Lidocaine allergy 2. Current participation in another scientific/clinical study 3. Pregnant or breastfeeding 4. Bleeding disorder/s 5. Current or recent smoker to include vaping (last 60 days) 6. Existence of food intolerances 7. Poor recent health as indicated in the general health questionnaire 8. Engage in uncommon eating practices (e.g. sustained periods of fasting) 9. Following a low dietary carbohydrate lifestyle
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Exogenous carbohydrate oxidation from a carbohydrate drink consumed during exercise, measured using a stable isotope tracer every 15 minutes during exercise | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Fluid absorption from a carbohydrate drink consumed during exercise, measured using the appearance of deuterated water in the bloodstream every 15 minutes during exercise after the 30-min timepoint 2. Self-rated gut comfort measured using visual analogue scales before and after exercise as well as every 15 min during exercise 3. Blood glucose regulation measured using analysis of plasma glucose concentrations every 15 min during exercise as well as before and after exercise 4. Muscle glycogen concentrations measured using biochemical analysis of glucose-6-phosphate after the breakdown of glycogen using hydrochloric acid just before and after exercise | — |
Countries
England, United Kingdom
Outcome results
None listed