The Study
Dose-Dependent Effects of Whey Peptide Intake on mTOR Signaling in Human Skeletal Muscle: 2079 Board #231 June 2, 2: 00 PM - 3: 30 PM.
This study looked at what happened in 10 people's muscles right after they drank a protein shake. It saw that a certain signal in their muscles got stronger, but it didn't compare it to what happens when they don't drink the shake. So we can't say the shake caused it — maybe they were just tired, or it was the time of day.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
After sleeping all night, your muscles are sleepy. Drinking a protein shake wakes them up by turning on a molecular switch called mTOR.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 534 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — this shows protein in the morning directly triggers muscle repair mechanisms, and women may respond more strongly than men to the same dose.
- 2After drinking 20g of whey peptide, muscle signaling increased within 1 hour.
- 3Women showed 2x stronger activation than men, and the more protein per kg of body weight, the stronger the signal (r²=0.71).
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Medicine & Science in Sports & Exercise
Year
2016
Authors
R. Kakigi, T. Yoshihara, Toshiharu Natsume, Noriko Ichinoseki‐Sekine, Hiroyuki Kobayashi, S. Machida, H. Naito
Related Content
Claims (5)
Consuming whey peptides raises levels of essential and branched-chain amino acids in the blood within one hour in both men and women, and the increase is the same size in both sexes.
After consuming whey peptides, healthy young women show a higher level of S6K1 protein phosphorylation at Thr389 than healthy young men, even when both groups receive the same dose and start with the same baseline phosphorylation.
Consuming 20 grams of whey peptide increases specific molecular markers of muscle signaling in healthy young adults within one hour, and the level of increase is directly related to the amount of peptide consumed per kilogram of body weight.
Eating 20 grams of protein in the morning after fasting overnight increases muscle amino acid levels and enables recovery.
Before consuming whey peptides, healthy young men and women have the same levels of mTOR and S6K1 phosphorylation in muscle tissue, indicating no difference in resting muscle signaling based on sex.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.