How To

Zwift How-To: Protein Planning for Muscle Building

on March 02, 2018

We often associate protein with muscle building and recovery, but it truly helps endurance athletes adapt to training. You train to get better, and gains come mainly from an improved muscle and cardiovascular system. These improvements are called training adaptations, typically derived from an accumulation of new proteins in the body.

The type of activity you do determines what proteins your body makes, but in all cases, nutrition can support the formation of these new proteins. With strength training, muscles grow and get stronger. In endurance training, you’ll develop more mitochondria – the power plants in your muscles that fuel muscle work. So, what are the main things we need to do to optimize these adaptations?

The fundamentals of protein for muscle adaptation

  1. Have 20g of quality protein after training
  2. Space meals 3-4 hours apart
  3. Choose high-quality protein

Have 20g of quality protein in each meal

Muscle is mostly made of proteins, so to build muscle mass or get more mitochondria we need to build proteins. For this process, we need two essential things: exercise, and feeding the muscle. Studies have shown that as little as 10 grams of protein, ingested after exercise can stimulate muscle building (the process is called protein synthesis). More studies show that ingesting 20g per meal is enough to obtain maximal effects. More is not needed. Dig into the science with this in-depth article on protein quantity.

The rule of thumb states that you must eat protein within an hour after finishing your workout. This is not necessarily true. Although that’s highly effective, replenishing with protein a little later still helps the process. So, there is no reason to panic if you miss that window. Use that time to eat, and recover.

Space meals 3-4 hours apart

Studies have compared the effects of eating 2 huge meals per day, 8 very small meals per day, or 4 moderate meals spaced three to four hours apart. The latter proved to be the most effective, with each meal providing 20 grams of protein. Read more on optimal protein intake for athletes. Or another related article on meal size and synthesis.

Choose high-quality protein

The type of protein matters. Proteins are made up of their building blocks: amino acids. There are 20 amino acids in total, with your diet contributing eight of them. Make sure that all essential amino acids are present each meal. The critical amino acid appears to be leucine. Whey protein is one of the most effective types of protein. Milk and meat are good sources of protein.

Generally, animal proteins fit this profile better than plant-based proteins. Plant-based proteins, however, can also be effective when ingested as combinations and in slightly higher amounts. Of the plant-based proteins, soy protein is the one that probably has the most efficient amino acid profile. More on animal versus plant proteins.



Asker Jeukendrup is one of the world’s leading sports nutrition scientists, who’s worked with many Olympic champions and weekend warriors. Asker is also a keen cyclist, runner, and triathlete himself. Read more at or chat up Asker while he’s riding in Watopia.

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