Influence of Sodium Bicarbonate on Time-to-exhaustion at Critical Power in Endurance Athletes

Study Overview
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Brief Summary
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During endurance exercise in the heavy and severe intensity domains, the rate at which metabolites that have been associated with the fatigue process (e.g. Pi, ADP, H, and extracellular K) accumulate increases. possibly leading to exercise cessation. Sodium bicarbonate, as a nutritional supplement, has gained attention over the past decades, because it might delay of offset fatigue. To date, there is a controversial discussion about which delivery mode (amount and frequency) might be best in optimizing endurance performance. Since the high ion load consequent to multiple ingestions might increase plasma volume, and consequently decrease bicarbonate concentrations, single acute ingestion could be more beneficial. However, in multi-day competitions or tournaments it might be necessary to use the supplement on a daily basis. Here, the investigators aim at investigating the effects of single dose or multiple dose (on five consecutive days) administration of bicarbonate vs. placebo increases endurance performance and acid-base homeostasis in trained male endurance athletes.

Conditions
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Performance

Intervention / Treatment
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* Dietary Supplement: Sodium bicarbonate
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: - male no cold or temperature at beginning or during the study between 18 and 45 years of age active in endurance sports (3 to 5 times per week a moderate to hart training) non-smoker no known cardiovascular or orthopedic problems no known limitations of kidney function no bearer of a cardiac pacemaker no medications with direct influence on the measurements. The whole intake of medicaments has to be declared in the health questionnaire by the participant. requirements of the health questionnaire fulfilled Exclusion criteria: - female male and age under 18 or over 45 years cold or temperature at the beginning or during the study untrained (less than 3 moderate trainings per week) smoker cardiovascular or orthopedic problems limitations of the kidney function bearer of a cardiac pacemaker medication with direct influence on the measurements. The whole intake of medicaments has to be declared in the health questionnaire by the participant. requirements of the health questionnaire not fulfilled

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Sodium bicarbonate<br> | Dietary Supplement: Sodium bicarbonate<br>* Ergogenic effect<br>|
| Placebo Comparator: Placebo<br> | Dietary Supplement: Placebo<br>* Placebo effect<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time-to-exhaustion |  | 5 weeks |