Athlete Protein Timing Calculator

Hitting your daily protein target is the main driver of muscle gain, but how you spread that protein across the day affects how much muscle protein synthesis you actually trigger. This calculator splits your daily target into even per-meal doses and checks each one against the leucine threshold.

How it works

Protein is divided evenly across your meal count, and each dose is checked against a practical minimum effective serving:

per meal     = daily target / meal count
threshold    = 25 g  (approximate leucine-threshold dose)
status       = per meal >= threshold ? optimal : below threshold

Muscle protein synthesis responds to each meal independently and saturates once a dose passes the leucine threshold, so several moderate doses outperform one or two large ones. One meal is highlighted as the post-training serving.

The leucine threshold in practice

Leucine is a branched-chain amino acid that acts as the primary molecular trigger for muscle protein synthesis. Each meal needs to provide enough leucine to maximally activate the mTOR signalling pathway. For most adults eating complete proteins (animal sources, soy, or well-combined plant proteins), this corresponds to roughly 20–40 g of total protein per serving, with the practical midpoint around 25 g used by this tool.

Below about 20 g of high-quality protein, the leucine signal is too weak to trigger a maximal muscle-building response. Above roughly 40–50 g, the excess protein is oxidised rather than used for additional muscle synthesis at that time — the muscle protein synthesis response does not keep rising indefinitely with dose.

This is why the optimal pattern for most athletes is 3–5 protein-rich meals rather than 1–2 large protein servings or 6–8 small ones. Three large meals each providing 40+ g cover the threshold well. Two meals need to be very large. Seven small meals each providing only 23 g fall short of maximally stimulating synthesis at each opportunity.

The post-training window: how important is it?

The “anabolic window” — the idea that protein must be consumed within 30–60 minutes of training or gains are lost — has been substantially revised by research. Current evidence suggests the window is wider than originally claimed: consuming protein within two to three hours of training is sufficient for most people. If you have eaten a protein-rich meal within a few hours before training, the window is even wider because amino acids are still being absorbed during and after the session.

That said, a post-training protein serving is still sensible and worth planning for:

• Training in a fasted state (morning workouts before eating) narrows the window and makes a post-training serving more time-sensitive
• A protein dose after training has well-established efficacy for muscle protein synthesis
• Planning the timing ensures you hit your daily total without relying on catching up later

Worked example

For an 80 kg athlete targeting 160 g of protein:

Four or five meals is the practical sweet spot for this athlete: every serving covers the threshold and the eating frequency is achievable. The post-training meal should be one of those four or five. It does not need to be a shake — a meal with sufficient protein and some carbohydrate works equally well.