Background
Protein ingestion increases muscle protein synthesis rates. The matrix in which protein is provided can strongly modulate the post-prandial muscle anabolic response. So far, the muscle anabolic response following whole foods ingestion remains largely unexplored.

Objective
To compare the impact of ingesting 30g protein provided as milk protein or cheese on post-prandial plasma amino acid concentrations and muscle protein synthesis rates at rest and during recovery from exercise in vivo in healthy, young males.

Methods
In this randomized, parallel-group intervention trial, twenty males ingested 30g protein provided as cheese or milk protein following a single-legged bout of exercise. Primed, continuous intravenous L-[ring-¹³C₆]-phenylalanine infusions were combined with the collection of blood and muscle tissue samples to assess post-absorptive and post-prandial muscle protein synthesis rates at rest and during recovery from exercise. Data were analyzed using repeated measures ANOVA with Time (basal vs post-prandial) and Leg (exercise vs rest; for muscle) as within-, and Group (milk vs cheese) as between-subjects factors. Data represent means±SDs.

Results
Plasma total amino acid concentrations increased after protein ingestion (Time: P<0.001), with greater increases following milk protein compared with cheese ingestion (Time*Group: P<0.001). Muscle protein synthesis rates increased following both cheese and milk protein ingestion from 0.037±0.014 to 0.055±0.018 %·h^-1 and 0.034±0.008 to 0.056±0.010 %·h^-1 at rest and from 0.031±0.010 to 0.067±0.013 %·h^-1 and 0.030±0.008 to 0.063±0.010 %·h^-1 following exercise, respectively (Time: P<0.05), with no differences between groups (Time*Group: P>0.05). Muscle protein synthesis rates increased more in the exercised when compared to the rested leg (Time*Leg: P=0.002).

Conclusion
Cheese ingestion increases muscle protein synthesis rates at rest and during recovery from exercise. The post-prandial muscle protein synthetic response to the ingestion of cheese or milk protein does not differ when 30g protein are ingested at rest or during recovery from exercise in healthy young males.