Impact of Training Load on the Gut miCrobiome And Its Relation to exeRcise Performance, mUscle Phenotype, and markerS of Overreaching in Healthy Men
Trial Parameters
Brief Summary
The goal of this study is to learn how different amounts of supervised indoor cycling training change gut health (gut bacteria, the substances gut bacteria make, and the gut barrier integrity), and how these changes relate to changes in fitness, muscle health, and signs of doing too much training (a state called 'overreaching'). The study includes healthy, recreationally active men aged 18 to 45 years. The primary questions, for which the study is powered (sufficient participants included), are: 1. Does moderate load training change blood and faecal levels of butyrate (a short-chain fatty acid made by gut bacteria) after eight weeks compared with a control group? 2. Compared to moderate load training, do higher training loads lead to different responses in blood and faecal levels of butyrate? Researchers will compare: * A control group that does not complete structured training; * A moderate-load training group that completes eight weeks of supervised cycling (4x/week); * A high-load training group that completes four weeks of moderate-load training followed by four weeks of higher training load (twice the number of training sessions). Participants will: * Be randomly assigned to one of the three groups; * Complete 8 weeks of supervised indoor cycling sessions if assigned to a training group; * Complete four study assessment periods (baseline, after week four, after week eight, and after a short taper (rest period); * Provide blood, stool, skeletal muscle, urine, saliva, and breath samples during the assessment periods; * Complete fitness and performance tests and questionnaires during the assessment periods.
Eligibility Criteria
Inclusion criteria: * Males between 18 and 45 years old. * Recreationally active individuals, with a weekly exercise training volume between one and six hours per week. * Good health status confirmed by a sport medical screening, which includes a sport medical questionnaire and resting electrocardiogram. * Body Mass Index (BMI) between 18.5 and 27.5 kg/m². * Masters the Dutch language. Exclusion criteria: * Engagement in strenuous competitive sports one month prior to or during the study intervention. * Medication and vaccination: Pro- or antibiotic treatment during the past three months, non-steroidal anti-inflammatory drugs (NSAIDs) or cholestyramine during the past month, drugs interfering with intestinal permeability (e.g., prokinetics, laxatives, lubiprostone, loperamide, anti-spasmodics, linaclotide, proton pump inhibitors) during the past month. Vaccinations within one month prior to or during the study intervention. * Blood donations within three months or plasma donation withi