Protein and Muscle Building: The Complete Scientific Guide (Dose, Timing, Sources)
What is the Optimal Protein Dose for Muscle Building?
According to the International Society of Sports Nutrition (ISSN) official position, optimal intake is 1.4 to 2.0 g of protein per kg body weight per day, distributed in 20-40g doses every 3-4 hours, with 700-3000mg leucine per serving.
Protein is the most studied nutrient in sports nutrition. Yet myths persist: "more is better", "you must eat within 30 minutes post-workout", "whey is essential". Here's what science really says.
ISSN Official Position on Protein
The International Society of Sports Nutrition position (DOI) establishes the following evidence-based recommendations:
Key ISSN Recommendations (Jäger et al., 2017)
- Daily intake: 1.4 to 2.0 g/kg/day for most athletes
- During caloric deficit: up to 2.3-3.1 g/kg/day to preserve lean mass
- Per serving: 0.25 g/kg or 20-40g high-quality protein
- Leucine: 700-3000 mg per serving to trigger protein synthesis
- Distribution: spread intake every 3-4 hours
The Anabolic Threshold
A review in Amino Acids (DOI) explains the anabolic threshold concept: the minimum level of protein needed to trigger muscle protein synthesis (MPS).
The Anabolic Window: Myth or Reality?
Contrary to popular belief, according to ISSN: the anabolic effect of exercise lasts at least 24 hours. There's no need to consume protein within 30 minutes post-training.
Practical Applications
Optimized Protein Plan
- Upon waking: 20-40g (after overnight fast)
- Pre or post-workout: 20-40g with 2-3g leucine
- Meals: distribute to reach 1.6-2.0 g/kg/day
- Before bed: 30-40g casein or cottage cheese
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Create my Smart Rabbit program❓ Frequently Asked Questions
How many grams of protein per day to build muscle?
According to ISSN, 1.4 to 2.0 g/kg body weight per day is sufficient for most athletes. An 80kg man should consume 112-160g of protein daily.
Do you really need to eat protein within 30 minutes after training?
No, that's a myth. The anabolic effect of exercise lasts at least 24 hours according to ISSN. Exact timing matters less than total daily intake.
Is whey protein essential for muscle building?
No. Complete food proteins (meat, eggs, fish, dairy) are equally effective. Whey is simply convenient, not superior.
What is leucine and why is it important?
Leucine is an essential amino acid that triggers muscle protein synthesis. ISSN recommends 700-3000mg per protein serving to maximize the anabolic effect.
Can you consume too much protein?
Intakes up to 3.0 g/kg/day are considered safe for healthy individuals without kidney or liver issues. Beyond that, benefits are limited.
👨💼 About the author
Jacques Chauvin - Fitness coach and founder of Smart Rabbit