Effects Of Leucine-Enriched Protein Supplementation On Subsequent Performance And Metabolism Following High-Intensity Cycling
Bibliographic record
Abstract
Recently we observed that the addition of leucine with protein to high-carbohydrate recovery feeding ingested following intense cycling over 3 days led to a small enhancement in subsequent performance. It is also established that post-exercise protein feeding, both with and without added leucine, attenuates muscle damage and soreness, and can increase muscle-protein synthesis, but the metabolic consequences are largely unknown. PURPOSE: To investigate further putative mechanisms and the effects on metabolism of a post-exercise leucine-protein supplement and confirm a benefit to subsequent performance. METHODS: In a double-blind randomized crossover, 12 male cyclists ingested either a leucine/protein/carbohydrate/fat supplement (LEUPRO; respectively 7.5/20/89/22 g·h-1) or isocaloric carbohydrate/fat control (CON: 119/22 g·h-1) for 1-3 h post-exercise during a 6-day training block. Protein intake was clamped at 1.9 (LEUPRO) and 1.5 g·kg-1d∑-1 (CON). Using stable isotope methodology and LC-MS based metabolomics we determined the impact of LEUPRO on leucine turnover and amino acid metabolism. RESULTS: Following exercise, LEUPRO increased branch-chain amino acids (BCAA) in plasma (2.6-fold; 90%CL ×/÷1.1) and urine (2.8-fold; ×/÷1.2) and products of their metabolism: plasma acylcarnitine C5 (3.0-fold; ×/÷0.9) and urinary β-aminoisobutyrate (3.4-fold; ×/÷1.4). LEUPRO also increased whole-body leucine oxidation (5.6-fold; ×/÷1.1) and synthesis (4.8-fold; ×/÷1.1), and only with LEUPRO was recovery leucine balance (mean ± SD: 580 ± 215 μmol·kg-1h∑-1, control; -43 ± 24 μmol·kg-1h∑-1) and day-1 nitrogen balance (17 ± 20 mg·kg-1, control; -90 ± 44 mg·kg-1) positive. However, subsequent day 2-5 nitrogen balance was positive in CON (111 ± 86 mg·kg-1; LEUPRO: 130 ± 110 mg·kg-1). LEUPRO reduced serum creatine kinase by 21-25% (90%CL ±14%). Despite these effects, the impact of LEUPRO on sprint power was trivial (day 4: 0.4% ±1.0%; day 6: -0.3% ±1.0%). CONCLUSIONS: Despite saturation of post-exercise BCAA metabolism and apparent attenuated tissue damage, a leucine-protein supplement had a trivial effect on performance compared to control, possibly due to both treatment groups being in positive nitrogen balance. Supported by a grant from Nestec Ltd., Vevey, Switzerland.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".