Related Experiment Video
Updated: May 24, 2026
08:22
Using an Ingestible Telemetric Temperature Pill to Assess Gastrointestinal Temperature During Exercise
Published on: October 7, 2015
Intestinal temperature, heart rate, and hydration status in multiday trail runners
Navin R Singh1, Emmerentia C Denissen, Andrew J McKune
1Division of Human Physiology and Department of Biokinetics, Exercise and Leisure Sciences, Faculty of Health Sciences, University of KwaZulu-Natal, Westville, Durban, South Africa.
Summary
This study found that maximum intestinal body temperature (Tintest) correlates more with metabolic rate than dehydration during trail running. Core body temperature changes were not significantly linked to serum osmolality or body mass shifts.
Area of Science:
- Exercise Physiology
- Sports Science
- Environmental Physiology
Background:
- Understanding physiological responses during endurance events is crucial for athlete performance and safety.
- Trail running presents unique physiological challenges due to varied terrain and elevation.
- Limited research exists on the interplay between core body temperature, heart rate, and hydration during multi-day trail running events.
Purpose of the Study:
- To assess changes in heart rate (HR), intestinal body temperature (Tintest), and hydration status.
- To investigate the relationships between these physiological parameters during a 3-day trail run.
- To determine if Tintest is more closely related to metabolic rate or hydration status.
Main Methods:
- A descriptive field study was conducted during the Three Cranes Challenge trail run in South Africa.
- Twelve amateur runners (5 men, 7 women) participated in a 95 km, 3-stage trail run.
- Physiological data including HR, Tintest, serum osmolality, and body mass were collected and analyzed.
Main Results:
- Environmental conditions were mild, with ambient temperatures ranging from 11.5-22.8°C.
- Mean HR averaged 150 bpm, with Tintest ranging from 36.1-40.2°C.
- A significant correlation was found between maximum Tintest and age-predicted maximum HR (R=0.58, P<0.05), but not with serum osmolality or body mass.
Conclusions:
- Maximum intestinal body temperature is more indicative of metabolic rate than percent dehydration during trail running.
- Core body temperature elevation during this event was not significantly associated with changes in serum osmolality or body mass.
- These findings contribute to understanding thermoregulation and hydration strategies in ultra-endurance trail running.
Related Concept Videos
01:27Assessing Body Temperature - Rectal
Rectal temperature measurement is considered the most precise method for assessing core body temperature and typically registers higher than oral temperature. For adults, the rectal thermometer should be inserted 1 to 1.5 inches into the rectum to obtain the most accurate reading.
Follow these steps for rectal temperature assessment:
Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
Follow these steps for rectal temperature assessment:
Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
01:19Assessing Body Temperature - Temporal Artery
Here is a stepwise guide to assessing the body temperature at the temporal artery using a temporal artery thermometer
Step 1: Perform hand hygiene and don a fresh pair of gloves to prevent cross-infection and ensure patient safety.
Step 2: Explain the procedure to the patient to establish trust. Clear communication establishes trust with the patient, ensures they understand what to expect, promotes cooperation, and enhances comfort during the procedure.
Step 3: Assess the patient's forehead...
Step 1: Perform hand hygiene and don a fresh pair of gloves to prevent cross-infection and ensure patient safety.
Step 2: Explain the procedure to the patient to establish trust. Clear communication establishes trust with the patient, ensures they understand what to expect, promotes cooperation, and enhances comfort during the procedure.
Step 3: Assess the patient's forehead...
01:14Assessing Body Temperature - Axilla
Procedural Guide for Assessing Axillary Body Temperature using a Digital Thermometer:
Step 1: Perform hand hygiene and put on clean gloves to maintain infection control and prevent cross-contamination.
Step 2: Prepare the patient by explaining the procedure to ensure understanding and cooperation. Ensure privacy, expose the axilla, and inform the patient that minimal movement is crucial for an accurate reading.
Step 3: Adjust the patient’s clothing to expose only the axilla. It minimizes...
Step 1: Perform hand hygiene and put on clean gloves to maintain infection control and prevent cross-contamination.
Step 2: Prepare the patient by explaining the procedure to ensure understanding and cooperation. Ensure privacy, expose the axilla, and inform the patient that minimal movement is crucial for an accurate reading.
Step 3: Adjust the patient’s clothing to expose only the axilla. It minimizes...
01:07Body Temperature
Body temperature reflects the equilibrium between heat production and heat loss within the body. Most heat is generated by metabolically active tissues, particularly the liver, heart, brain, kidneys, and endocrine organs. At rest, skeletal muscles contribute 20–30% of total heat production, but during vigorous exercise, this can increase up to 30–40 times.
The average body temperature is approximately 37°C (98.6°F) and typically ranges from 36.1–37.2°C (97–99°F), remaining relatively stable...
The average body temperature is approximately 37°C (98.6°F) and typically ranges from 36.1–37.2°C (97–99°F), remaining relatively stable...
01:25Body Temperature
The body's temperature, measured in degrees, is determined by the balance between heat production and dissipation to the surrounding environment. For instance, if exercising vigorously, the body will produce more heat, causing sweat and dissipating that heat. Despite extreme environmental conditions and physical exertion, the human temperature-control system maintains a constant core body temperature (the temperature of deep tissues, which are the tissues located beneath the skin and other...
01:14Assessing Body Temperature - Oral
Here are the steps to accurately measure oral temperature using an electronic thermometer:
Step 1:
Start by practicing proper hand hygiene to prevent the spread of microorganisms.
Step 2:
Take the thermometer out of the charging unit, switch it on, and wait for the ready sign.
Step 3:
Gently slide the probe cover until a click is heard. This simple action prevents cross-contamination and ensures the correct placement of the probe cover.
Step 4:
Instruct the patient to open their mouth and place...
Step 1:
Start by practicing proper hand hygiene to prevent the spread of microorganisms.
Step 2:
Take the thermometer out of the charging unit, switch it on, and wait for the ready sign.
Step 3:
Gently slide the probe cover until a click is heard. This simple action prevents cross-contamination and ensures the correct placement of the probe cover.
Step 4:
Instruct the patient to open their mouth and place...