Glucose Metabolism
Conditions
Keywords
glucose levels, endurance exercise, continuous glucose monitoring
Brief summary
As part of the mandatory annual assessment of physical fitness, soldiers are required to complete a standardized military march. A total of 100 healthy volunteer participants will be recruited from soldiers serving at the Bundeswehr Hospital Ulm. During this march, physiological and metabolic parameters will be assessed. At baseline, anthropometric data and information on medical history, lifestyle, and fitness status will be collected, including a validated questionnaire on physical activity. Blood and urine samples will be obtained to determine routine laboratory and metabolic parameters, and body composition will be assessed using bioelectrical impedance analysis. In addition, selected sensors will be applied to continuously record physiological data. Participants will then complete a 6 km march carrying 15 kg of equipment. After completion of the march, sensors will be removed and additional blood and urine samples will be collected to evaluate metabolic responses to physical exertion, including catecholamine levels.
Detailed description
In this study, physiological data from healthy volunteers will be investigated. A total of 100 healthy volunteer participants will be recruited from soldiers serving at the Bundeswehr Hospital Ulm. As part of the mandatory annual assessment of physical fitness required by their employer, these individuals must complete a standardized military march. During this march, metabolic parameters will be assessed. At the beginning of the study, anthropometric data as well as general information regarding medical history, lifestyle, and fitness status will be collected using a baseline questionnaire developed by the Section of Endocrinology and Diabetology. In addition, a validated questionnaire on physical activity (BSA questionnaire) will be administered. The information obtained will support the interpretation of physiological parameters, as individual fitness levels may influence heart rate and glucose dynamics. Blood samples (maximum 60 mL) and urine samples will be collected to determine routine laboratory parameters as well as metabolic markers. Participants will undergo bioelectrical impedance analysis to assess body composition. To collect physiological data, selected sensors and devices will be attached to the participants (continuous glucose monitoring, electrocardiography). After the sensors have been applied and calibrated, participants will complete a 6 km march carrying 15 kg of equipment. The march will be conducted in uniform in accordance with central military regulations, with standardized marching equipment and a fixed route consisting of two laps around the grounds of the Bundeswehr Hospital Ulm. At the end of the march, the sensors will be removed by the study physicians. Subsequently, an additional blood sample (maximum 60 mL) will be collected to assess metabolic parameters following physical exertion, and a urine sample will be obtained for the analysis of catecholamines. Restricting participation to soldiers provides optimal conditions for investigating glucose dynamics and their influencing factors during endurance exercise in healthy individuals. Soldiers undergo regular comprehensive health check-ups every three years, including medical questionnaires, physical examinations, laboratory diagnostics, and additional specialist evaluations when indicated. Conditions such as prediabetes or arterial hypertension are therefore detected and treated at an early stage, resulting in a medically well-screened cohort of healthy individuals. Scientific data on glucose dynamics during physical exercise are already available for individuals with diabetes and for professional athletes. However, data in healthy individuals remain limited. The pre-screened cohort of soldiers is therefore particularly suitable for addressing this research question. Compared with other potential study populations, such as participants recruited from university recreational sports programs, this cohort offers several advantages, including a broader range of fitness levels, a wider age distribution (up to 65 years), and substantial experience with the specific exercise task. The annually performed 6 km march with load is conducted under standardized conditions and is familiar to the participants, thereby minimizing stress-related metabolic effects. Standardized clothing and equipment further reduce potential external confounding factors.
Interventions
OTHERStandardized military march
6 km march carrying 15 kg of equipment. The march will be conducted in uniform in accordance with central military regulations. Participants will be equipped with a continuous glucose monitor an electrocardiography wearable during the march. Before and after the march blood and urine samples will be obtained.
Sponsors
University of Ulm
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* BMI between 18.5 and 30 kg/m\^2
Exclusion criteria
* Pregnancy or lactation * cardiovascular disease * vegan diet * drug or alcohol abuse * Drug therapy that raises or lowers blood sugar, e.g. steroids, antidiabetics, insulin or influences the autonomic nervous system * No consent to be informed about incidentally discovered pathological findings * Any other (clinical) condition that would endanger participants safety or question scientific success according to the physicians opinion.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Glucose dynamics during exercise | 1 hour | Interstitial glucose responses during the standardized endurance exercise (6 kilometer march with 15 kilogram load) measured via continuous glucose monitoring. |
| Sympathetic nervous system activation (catecholamines) | Baseline, immediately after the march (approximately 1 hour after baseline) | Activation of the sympathetic nervous system during a standardized endurance exercise measured via changes in catecholamine levels. |
| Correlation between sympathetic activation (catecholamines) and glucose dynamics during endurance exercise | Baseline, during the 1 hour-march, immediately after the march (approximately 1 hour after baseline) | Correlation between sympathetic nervous system activation measured via catecholamine levels and glucose responses during a standardized endurance exercise (6 kilometer march with 15 kilogram load). |
| Heart rate variability | Baseline, during the 1 hour-march, immediately after the march (approximately 1 hour after baseline) | Heat rate variability during a standardized endurance exercise measured via electrocardiography. |
| Correlation between heart rate variability and glucose dynamics during endurance exercise | Baseline, during the 1 hour-march, immediately after the march (approximately 1 hour after baseline) | Correlation between heart rate variability and glucose responses during a standardized endurance exercise (6 kilometer march with 15 kilogram load). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Training status | Baseline | Individual fitness level assessed via the Movement and Sport Activity questionnaire (sport and physical activity based on reported frequency and duration of activities and provides estimates of activity in minutes per week or MET-hours per week) |
| Correlation between training status and glucose dynamics during endurance exercise | Baseline, during the 1 hour-march, immediately after the march (approximately 1 hour after baseline) | Correlation between training status and glucose responses during the standardized endurance exercise. |
| Body composition | Baseline. | Muscle mass in kilogram assessed by bioelectrical impedance analysis. |
| Correlation between body composition and glucose dynamics during exercise. | Baseline, during the 1 hour-march, immediately after the march (approximately 1 hour after baseline) | Correlation between muscle mass and glucose responses during the standardized endurance exercise. |
| Biomarkers of inflammatory response | Baseline and immediately after the march (approximately 1 hour after baseline) | Inflammatory markers measured in blood samples. |
| Correlation between inflammatory markers with glucose dynamics during exercise. | Baseline, during the 1 hour-march, immediately after the march (approximately 1 hour after baseline) | Correlation between inflammatory markers and glucose responses to endurance exercise. |
| Cortisol levels | Baseline and immediately after the march (approximately 1 hour after baseline) | Cortisol levels measured from blood samples. |
| Correlation between cortisol levels and glucose dynamics during exercise. | Baseline, during the 1 hour-march, immediately after the march (approximately 1 hour after baseline) | Correlation between changes in cortisol levels and glucose responses during the standardized endurance exercise |
| Biomarkers of lipolysis | Baseline, immediately after the march (approximately 1 hour after baseline) | Biomarkers of lipolysis measured from blood samples. |
| Correlation between lipolysis and glucose dynamics during endurance exercise | Baseline, during the 1 hour-march, immediately after the march (approximately 1 hour after baseline) | Correlation between changes in biomarkers of lipolysis and with glucose dynamics during endurance exercise. |
Countries
Germany
Contacts
CONTACTMartin Heni, MD
CONTACTSabrina Wanglelr
PRINCIPAL_INVESTIGATORMartin Heni, MD
University of Ulm
Outcome results
None listed