Protein Supplementation and Endurance Exercise Adaptations

Study Overview
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Brief Summary
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Participants will perform three endurance training sessions weekly for 12 weeks. All participants will be randomly assigned to the protein supplementation group or the placebo (iso-caloric carbohydrate) group. During the 12 weeks endurance training program participants allocated to the protein group (30 g protein per beverage) will receive a protein drink after exercise and prior to sleep at night on training days. On non-training days participants will only receive a protein drink before sleep. Participants allocated to the carbohydrate group (30 g carbohydrates) will receive a carbohydrate drink instead of a protein drink.

Detailed Description
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In the proposed study, the effects of protein supplementation after training and before sleep on VO2max and performance will be assessed during 12 weeks endurance exercise training in untrained healthy young men. The ready to drink carbohydrate beverage consists of 30g carbohydrate or 30g protein. Previous studies show that the supplementation of 30g protein is in the optimal range to stimulate the muscle protein synthetic response following resistance type exercise. The protein supplementation group in the present study will be compared with an iso-caloric carbohydrate group. In addition, to the pre- and post-intervention biopsies 1 additional muscle biopsies will be taken (in week 6) during the 12 week intervention period. This will create a unique opportunity to establish the timeline of the skeletal muscle adaptive response at functional and mechanistic level following prolonged endurance exercise training, including potential differences between both groups.

Official Title
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The Impact of Protein Supplementation to Maximize Skeletal Muscle Endurance Training Adaptations in Healthy Young Men

Conditions
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Exercise

Intervention / Treatment
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* Dietary Supplement: Protein


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male Age between 18 and 30 years of age BMI between 18.5 - 25 kg/m2 Recreationally active, performing sports on a non-competitive basis Maximal wattage of > 5 watt per kg bodyweight (screening measurement) Willing to give muscle biopsies Willing to give blood samples Having a general-practitioner Consumption of alcohol beverages is less than 21 per week Able to perform three exercise sessions weekly for 10 weeks Exclusion Criteria: Medical condition that can interfere with the study outcome (i.e. cardiovascular disease, pulmonary disease, liver or renal disease, diabetes mellitus type 1 or 2) Having a lactose and/or gluten intolerance Use of systemic medication (with the exception of antihistaminic medication and the use of occasional painkillers) (Chronic) injuries of the locomotor system (e.g. musculoskeletal/orthopedic disorders) that can interfere with the intervention Participants who are enrolled in an interventional biomedical research project or have received an investigational new drug or product with the last 30 days prior to screening. Smokers and use of illicit drugs Blood donor during the study and in the three months before start of the study Employed, or intern, or working on a thesis at the department of Human Nutrition at Wageningen University & Research Participating in another scientific study (except EetMeetWeet)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants will perform three endurance training sessions weekly for 12 weeks. All participants will be randomly assigned to the protein supplementation group or the placebo (iso-caloric carbohydrate) group. During the 12 weeks endurance training program participants allocated to the protein group (30 g protein per beverage) will receive a protein drink after exercise and prior to sleep at night on training days. On non-training days participants will only receive a protein drink before sleep. Participants allocated to the carbohydrate group (30 g carbohydrates) will receive a carbohydrate drink instead of a protein drink.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Protein<br>Three endurance training sessions weekly with protein supplementation post-exercise and before sleep. | Dietary Supplement: Protein<br>* Three endurance training sessions weekly with protein supplementation post-exercise and before sleep.<br>|
| Placebo Comparator: Carbohydrate<br>Three endurance training sessions weekly with carbohydrate supplementation post-exercise and before sleep. | Dietary Supplement: Protein<br>* Three endurance training sessions weekly with protein supplementation post-exercise and before sleep.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximal whole-body oxidative capacity | Maximal oxygen consumption in ml per kg of bodyweight | Baseline | 
| Maximal whole-body oxidative capacity | Maximal oxygen consumption in ml per kg of bodyweight | 6 weeks | 
| Maximal whole-body oxidative capacity | Maximal oxygen consumption in ml per kg of bodyweight | 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Endurance Performance | 10-km simulated time trial performance in seconds | Baseline | 
| Endurance Performance | 10-km simulated time trial performance in seconds | 6 weeks | 
| Endurance Performance | 10-km simulated time trial performance in seconds | 12 weeks | 
| Maximal activity of citrate synthase | Maximal activity of citrate synthase in micromol per gram per minute | Baseline | 
| Maximal activity of citrate synthase | Maximal activity of citrate synthase in micromol per gram per minute | 6 weeks | 
| Maximal activity of citrate synthase | Maximal activity of citrate synthase in micromol per gram per minute | 12 weeks | 
| Maximal activity of Cytochrome c oxidase | Maximal activity of Cytochrome c oxidase in micromol per gram per minute | Baseline | 
| Maximal activity of Cytochrome c oxidase | Maximal activity of Cytochrome c oxidase in micromol per gram per minute | 6 weeks | 
| Maximal activity of Cytochrome c oxidase | Maximal activity of Cytochrome c oxidase in micromol per gram per minute | 12 weeks | 
| Erythrocytes | Erythrocytes count/pL | Baseline | 
| Erythrocytes | Erythrocytes count/pL | 2 weeks | 
| Erythrocytes | Erythrocytes count/pL | 4 weeks | 
| Erythrocytes | Erythrocytes count/pL | 6 weeks | 
| Erythrocytes | Erythrocytes count/pL | 8 weeks | 
| Erythrocytes | Erythrocytes count/pL | 10 weeks | 
| Erythrocytes | Erythrocytes count/pL | 12 weeks | 
| Hemoglobin | Hemoglobin mmol/L | Baseline | 
| Hemoglobin | Hemoglobin mmol/L | 2 weeks | 
| Hemoglobin | Hemoglobin mmol/L | 4 weeks | 
| Hemoglobin | Hemoglobin mmol/L | 6 weeks | 
| Hemoglobin | Hemoglobin mmol/L | 8 weeks | 
| Hemoglobin | Hemoglobin mmol/L | 10 weeks | 
| Hemoglobin | Hemoglobin mmol/L | 12 weeks | 
| Hematocrit | Hematocrit L/L | Baseline | 
| Hematocrit | Hematocrit L/L | 2 weeks | 
| Hematocrit | Hematocrit L/L | 4 weeks | 
| Hematocrit | Hematocrit L/L | 6 weeks | 
| Hematocrit | Hematocrit L/L | 8 weeks | 
| Hematocrit | Hematocrit L/L | 10 weeks | 
| Hematocrit | Hematocrit L/L | 12 weeks | 
| Lean mass | Lean mass kg | Baseline | 
| Lean mass | Lean mass kg | 6 weeks | 
| Lean mass | Lean mass kg | 12 weeks | 
| Fat mass | Fat mass kg | Baseline | 
| Fat mass | Fat mass kg | 6 weeks | 
| Fat mass | Fat mass kg | 12 weeks |