Place · Level 3
Protein + lifting
1.6-2.2 g/kg/天 (Morton 2018 meta) · 每餐 0.3-0.5 g/kg · 30 分钟窗口是营销
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Chapter 1
Where 1.6-2.2 comes from
Where 1.6-2.2 comes from
*Morton 2018 BJSM* meta-analysis is the authoritative source for this number:
49 RCTs, n = 1863 subjectsComparing different protein intakes plus resistance training (RT) for effects on lean mass and strengthResult: the breakpoint between protein intake and lean mass gain is 1.62 g/kg/dayBeyond that point, further increases in protein give diminishing returnsThe 95% CI upper bound is about 2.2 g/kg/day, hence the recommended range of 1.6-2.2 g/kg/day
Contrast with the RDA: both the US and Chinese RDAs are 0.8 g/kg/day — that is the deficiency-prevention dose, not the training-optimization dose. For trainees, the RDA dramatically underestimates the requirement.
Example (a 70 kg trainee): 70 × 1.8 = 126 g protein/day, split across 4 meals × 30-35 g per meal.
Real-food equivalents:
100 g cooked chicken breast ≈ 28 g protein1 egg ≈ 6-7 g1 cup milk (240 mL) ≈ 8 g150 g Greek yogurt ≈ 15 g100 g tofu ≈ 8 g (firm) / 5 g (silken)
49 RCTs, n = 1863 subjectsComparing different protein intakes plus resistance training (RT) for effects on lean mass and strengthResult: the breakpoint between protein intake and lean mass gain is 1.62 g/kg/dayBeyond that point, further increases in protein give diminishing returnsThe 95% CI upper bound is about 2.2 g/kg/day, hence the recommended range of 1.6-2.2 g/kg/day
Contrast with the RDA: both the US and Chinese RDAs are 0.8 g/kg/day — that is the deficiency-prevention dose, not the training-optimization dose. For trainees, the RDA dramatically underestimates the requirement.
Example (a 70 kg trainee): 70 × 1.8 = 126 g protein/day, split across 4 meals × 30-35 g per meal.
Real-food equivalents:
100 g cooked chicken breast ≈ 28 g protein1 egg ≈ 6-7 g1 cup milk (240 mL) ≈ 8 g150 g Greek yogurt ≈ 15 g100 g tofu ≈ 8 g (firm) / 5 g (silken)
Chapter 2
0.3-0.5 g/kg per meal
0.3-0.5 g/kg per meal
*Areta 2013* and *Schoenfeld 2018* meta-analyses reveal how much distribution actually matters:
With the same 24-hour protein total (1.6 g/kg), splitting it across 3-4 meals (0.3-0.5 g/kg per meal) is significantly better than 1-2 large mealsReason: each meal's muscle protein synthesis (MPS) has both a leucine threshold (~2.5 g) and an absorption ceiling — a single protein dose above ~40 g gives marginal benefit0.3-0.5 g/kg per meal works out to about 25-40 g of protein — enough to hit the leucine threshold without waste
Layne Norton's classic demonstration (a 70 kg trainee at 130 g protein/day):
Option A: 65 g at breakfast + 65 g at dinner (2 meals) — protein synthesis sub-optimalOption B: 32 g breakfast + 32 g lunch + 32 g dinner + 32 g pre-bed (4 meals) — protein synthesis maximized
Trent Stellingwerff's approach: 5-6 meals on training days (with a small post-training feed), 4 meals on rest days — both landing at 1.8 g/kg.
With the same 24-hour protein total (1.6 g/kg), splitting it across 3-4 meals (0.3-0.5 g/kg per meal) is significantly better than 1-2 large mealsReason: each meal's muscle protein synthesis (MPS) has both a leucine threshold (~2.5 g) and an absorption ceiling — a single protein dose above ~40 g gives marginal benefit0.3-0.5 g/kg per meal works out to about 25-40 g of protein — enough to hit the leucine threshold without waste
Layne Norton's classic demonstration (a 70 kg trainee at 130 g protein/day):
Option A: 65 g at breakfast + 65 g at dinner (2 meals) — protein synthesis sub-optimalOption B: 32 g breakfast + 32 g lunch + 32 g dinner + 32 g pre-bed (4 meals) — protein synthesis maximized
Trent Stellingwerff's approach: 5-6 meals on training days (with a small post-training feed), 4 meals on rest days — both landing at 1.8 g/kg.
The 30-min protein window
See hypertrophy-mechanism for the full debunk. Bringing the data together here:*Aragon & Schoenfeld 2013* *JISSN* meta-analysis nails it down:
The real anabolic window is 24-48 hours after training, not 30 minutes24-hour total protein matters far more than timingA normal protein-containing meal 1-3 hours before training, plus another 1-2 hours after, already covers the whole window
Things not to do in practice:
Interrupting your day to make sure you get a protein shake right before training (a normal dinner already contains 30-40 g of protein)Panicking if you don't get protein within 30 min post-training (within 2-3 hours is fine)Pushing past 40 g per meal in search of "more" (absorption and leucine triggering are already saturated)
Chapter 3
Protein quality + sources
Protein quality + sources
DIAAS (Digestible Indispensable Amino Acid Score) is the modern standard for protein quality, replacing the older PDCAAS:
The implication: animal protein has more favorable leucine and EAA ratios, making it easier to hit the MPS threshold. But plant protein is not unusable — it just needs slightly higher total intake (about 1.8-2.0 g/kg) plus protein combining (legumes + grains) to compensate for the limiting amino acid in any single plant source (soy is low in methionine, grains are low in lysine).
Practical for vegan trainees: soy protein, pea-rice protein blends, various legumes, whole grains, with occasional leucine-rich BCAA supplementation — fully workable. *Hevia-Larraín 2021* RCT showed equivalence to whey.
| Source | DIAAS | Notes |
|---|---|---|
| Whey protein | 1.09 | Benchmark |
| Milk | 1.18 | Highest |
| Egg | 1.13 | |
| Beef | 1.10 | |
| Chicken breast | 1.08 | |
| Soy protein | 0.91 | Highest plant |
| Tofu | 0.87 | |
| Pea protein | 0.65 | |
| Wheat gluten | 0.40 |
The implication: animal protein has more favorable leucine and EAA ratios, making it easier to hit the MPS threshold. But plant protein is not unusable — it just needs slightly higher total intake (about 1.8-2.0 g/kg) plus protein combining (legumes + grains) to compensate for the limiting amino acid in any single plant source (soy is low in methionine, grains are low in lysine).
Practical for vegan trainees: soy protein, pea-rice protein blends, various legumes, whole grains, with occasional leucine-rich BCAA supplementation — fully workable. *Hevia-Larraín 2021* RCT showed equivalence to whey.
Chapter 4
Older adults need more
Older adults need more
Protein requirements rise after age 60 — not because the muscle synthesis machinery becomes faster, but because it becomes blunted (anabolic resistance, *Bauer 2013*):
The older muscle's synthetic response to the same protein dose drops by about 50%The leucine threshold rises — older adults need about 35-40 g of protein per meal (vs 25-30 g in young adults) to trigger adequate MPSThe PROT-AGE Study Group 2013 recommends 1.0-1.2 g/kg/day for healthy older adults, and 1.2-1.5 g/kg/day for active older adults or those with chronic disease
The clinical implication: prevention and management of sarcopenia does not call for "gentle senior food" — it calls for a combined intervention of 30-40 g protein per meal plus 2-3 sessions of resistance training per week. In the *Fiatarone 1994* *NEJM* nonagenarian resistance training trial, protein fortification was one of the key variables.
Cross-continent references: sarcopenia / osteoporosis / vitamin-d (vitamin D improves the elderly MPS response, per *Bischoff-Ferrari 2019*).
The older muscle's synthetic response to the same protein dose drops by about 50%The leucine threshold rises — older adults need about 35-40 g of protein per meal (vs 25-30 g in young adults) to trigger adequate MPSThe PROT-AGE Study Group 2013 recommends 1.0-1.2 g/kg/day for healthy older adults, and 1.2-1.5 g/kg/day for active older adults or those with chronic disease
The clinical implication: prevention and management of sarcopenia does not call for "gentle senior food" — it calls for a combined intervention of 30-40 g protein per meal plus 2-3 sessions of resistance training per week. In the *Fiatarone 1994* *NEJM* nonagenarian resistance training trial, protein fortification was one of the key variables.
Cross-continent references: sarcopenia / osteoporosis / vitamin-d (vitamin D improves the elderly MPS response, per *Bischoff-Ferrari 2019*).