Exercise-induced gastrointestinal, inflammatory, mitochondrial, and muscular stress responses during prolonged running in healthy endurance athletes.
Conditions
Interventions
Group 1: Moderate carbohydrate intake
Participants complete a standardized 4-hour running trial at moderate intensity, corresponding to approximately 60–65% of individually determined VO2peak. During
Sponsors
Sport- und Rehabilitationsmedizin Universitätsklinikum Ulm
Eligibility
Sex/Gender
All
Age
18 Years to 50 Years
Inclusion criteria
Inclusion criteria: -trained endurance athletes aged 18–50 years regular running-based endurance training of at least 5–6 hours per week for at least two years -previous participation in at least one marathon or a comparable prolonged running event -VO2peak = 50 ml/kg/min in men and = 45 ml/kg/min in women -ability to follow verbal instructions and safely complete the exercise protocol
Exclusion criteria
Exclusion criteria: -orthopedic complaints or injuries currently limiting prolonged running -acute or chronic internal medical diseases -known chronic gastrointestinal diseases or regularly occurring gastrointestinal symptoms during prolonged running -abnormal stool habits outside the normal range, defined as regular formed stool between three times per day and once every three days -known allergies or intolerances to ingredients of the sports nutrition products used, particularly glucose, fructose, maltodextrin, sodium alginate, pectin, sodium bicarbonate, or calcium carbonate -known fructose intolerance or relevant fructose malabsorption -known intolerance to sports gels or carbohydrate-containing sports drinks -pregnancy or breastfeeding -use of medication that may relevantly affect metabolism, immune function, or physical performance
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Change in I-FABP concentration as a marker of intestinal epithelial cell damage, compared between moderate carbohydrate intake (75 g/h) and high carbohydrate intake (120 g/h) during prolonged running. Assessment: I-FABP will be measured in venous blood samples. Samples will be collected before exercise (T0), immediately after exercise, 1 hour after exercise, and 24 hours after exercise. The primary comparison will be based on the change in I-FABP concentration between the two carbohydrate intake conditions. | — |
Secondary
| Measure | Time frame |
|---|---|
| Changes in the following parameters compared between the two carbohydrate intake conditions: markers of endotoxin-related immune activation: LBP, sCD14 markers of systemic inflammation: IL-6, TNF-a, hsCRP markers of mitochondrial stress responses: mtDNA copy number, cell-free mtDNA markers of muscular stress or muscle damage: CKM, LDH markers of energetic regulation: leptin, ghrelin physiological and perceptual exercise parameters: heart rate, Borg scale/RPE gastrointestinal symptoms during and after exercise capillary blood parameters during exercise, e.g. glucose and/or lactate, depending on the final analysis plan Assessment: Laboratory and molecular secondary endpoints will be assessed from venous blood samples collected at T0, immediately after exercise, 1 hour after exercise, and 24 hours after exercise. Additional capillary blood samples will be collected during exercise after 1, 2, and 3 hours, as well as immediately after exercise, for selected acute parameters. Heart rate and perceived exertion will be repeatedly recorded during the running trial. Gastrointestinal symptoms will be documented during and after exercise using standardized procedures. The sampling schedule is based on the expected kinetics of the investigated markers. | — |
Countries
Austria, Germany, Switzerland
Contacts
Public ContactDaniel Alexander Bizjak
Sport- und Rehabilitationsmedizin Universitätsklinikum Ulm
Outcome results
None listed