Effects of Whey Protein Isolate Ingestion on Muscle Protein Synthesis at Rest and After Resistance-exercise in Middle-aged Men: A Research Protocol
Bibliographic record
Abstract
Introduction: Sarcopenia is a syndrome primarily found in elderly individuals and is defined by decreased skeletal muscle mass and strength. Sarcopenia often increases the risk or is comorbid with various diseases. Thus, the objective of this study is to determine the appropriate dosage of whey protein isolate (WPI) for middle-aged men at rest and after resistance-exercise for maximum muscle protein synthesis (MPS) and to reduce the risk of sarcopenia. Methods: 50 healthy men (age 45± 5yrs, BMI < 30 kg/m2) will be randomly assigned an amount of ingested WPI (0g,10g,20g,30g,40g). 24 hours prior, a baseline saliva sample and ingestion of 5 doses of 150 mL bolus (70% D2O) every 2 hours will be completed at the participants’ own homes. On the day of the study, a saliva sample will be taken 1 hour before 10 repetitions of maximum unilateral leg extension. After the exercise protocol (t = 0 h), saliva samples will be obtained every hour until t = 6 h and 3 muscle biopsies at t = 0 h, t = 3 h, and t = 6 h. After isolating myofibrillar protein fractions from the biopsies, the samples will be analyzed using gas chromatography-pyrolysis-isotope ratio mass spectrometer (GC-P-IRMS). Analysing saliva samples will be conducted using temperature conversion elemental analyzer (TC/EA) followed by isotope ratio mass spectrometer (IRMS). Atom percent excess for both deuterium enrichment of protein-bound alanine and precursor enrichment will be conducted to allow the calculation of fractional synthetic rate (FSR, %/h). Discussion: We anticipate FSR (%/h) will be significantly greater in the exercised leg compared to the unexercised leg at each WPI ingestion dosage. Furthermore, we anticipate that ≥20 g of ingested WPI will be sufficient for maximal MPS at rest. Finally, we anticipate that at ≥30 g ingestion of WPI will be sufficient for maximal MPS after resistance training. It is beneficial for physicians to know the optimal dose for MPS in middle-aged adults, so they can suggest more accurate recommendations of proactive protein intake. This will help alleviate the high prevalence of sarcopenia and its detrimental effects on health, healthcare, and the economy.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.002 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.005 | 0.003 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.003 | 0.002 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.017 | 0.003 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".