New research from our lab:
How much protein is needed after endurance exercise?
Protein ingestion after exercise stimulates muscle protein synthesis (the main process regulating muscle recovery, adaptation and growth). It has been well established that protein intake improves resistance training adaptations. But little is known about the impact of protein on muscle adaptations following endurance exercise.
We investigated the impact of 15, 30, and 45 g of milk protein during recovery of a single session of endurance exercise in trained cyclists. Both myofibrillar (contraction) and mitochondrial (energy production) protein synthesis were measured. The endurance exercise consisted of 1.5 hours of cycling on 60% of the Wmax of the subject.
None of the protein doses stimulated mitochondrial protein synthesis rates.
In addition, 15 g of milk protein was not enough to significantly stimulate myofibrillar protein synthesis after the cycling exercise. But both the 30 and 45 g protein dose stimulated myofibrillar protein synthesis after cycling, with no significant differences between the doses. Statistical analyses showed that ~0.49 g/kg was the optimal dose.
Go to the next infographic in the protein series:
Only a short muscle growth response to BCAA?
May I ask why milk protein, rather than whey protein, is chooesed as the protein source for endurance exercise?
The study used intrinsically-labeled protein. That is protein that has stable isotope tracers in it. It allows you to follow the ingested protein throughout the body (how much is absorbed, how much ends up in muscle, etc). It takes a lot of time and money to make it (you cannot buy it somewhere).
In this case, they made the intrinsically-labeled protein for other research studies where they were specifically interested in milk protein. Since we had enough left, we used it for this study so we could do more fancy measurements. We did not choose milk specifically over whey.
Fascinating, keep up the good work!