Overview
This lecture addresses optimal protein intake for muscle building post-resistance training, discussing timing, amount, and the concept of the "anabolic window."
Recommended Protein Intake Post-Resistance Training
- An effective dose for maximizing muscle protein synthesis is 0.4–0.6 g/kg (0.2–0.25 g/lb) body weight per meal.
- Typical post-training meals should contain 30–50 g of protein but doses above this are rarely studied.
- Total daily intake should be approximately 1.6–2.2 g/kg (0.7–1 g/lb) body weight for optimal muscle gain.
Protein Timing and the Anabolic Window
- Early research suggested a narrow 30–60 minute post-exercise "anabolic window" for protein intake.
- This hypothesis was based on fasted subjects but is less relevant if a pre-exercise meal was consumed.
- The anabolic/anti-catabolic effect of a meal can last 3–6 hours, depending on meal size.
- Meta-analyses show that as long as total daily protein meets recommended levels, timing relative to training is not crucial for most people.
Protein Distribution and Practical Considerations
- Even if protein intake is uneven through the day (e.g., heavier at dinner), there is no major negative impact on muscle or health for general populations.
- Studies comparing protein intake immediately pre- vs post-exercise show no significant difference in muscle or strength gains.
- Nutrients take 1–2 hours to peak in circulation, meaning pre-exercise meals contribute to post-exercise recovery.
- Muscle protein synthesis remains elevated for up to 24–72 hours after resistance training.
Hierarchy of Protein Importance
- Total daily protein intake is most important; timing is secondary.
- The "anabolic window" is more flexible than previously thought, spanning hours to days.
- Protein timing becomes more critical only for elite athletes or those with highly specific physique goals.
Key Terms & Definitions
- Muscle Protein Synthesis (MPS) — The process by which the body builds new muscle proteins after exercise.
- Anabolic Window — The theorized short time after exercise when nutrient intake is thought to maximize muscle growth.
- Meta-analysis — A study that combines results from multiple studies to draw broader conclusions.
Action Items / Next Steps
- Calculate your protein needs: aim for 0.7–1 g per lb body weight daily.
- Focus on total daily protein rather than obsessing over timing post-exercise.
- Distribute protein across meals as convenient; do not stress over exact post-workout intake timing.