Background: Resistance exercise and protein intake are both strong stimuli for muscle protein synthesis. The potential for a protein to acutely increase muscle protein synthesis seems partly dependent on absorption kinetics and the amino acid composition. The aim of this double-blinded randomized cross-over study was to compare time dependent changes in blood amino acid concentrations after ingesting 20 g of five distinct high quality dairy protein supplements (native whey, whey protein concentrate 80, hydrolysed whey, microparticulated whey, and milk proteins). Furthermore, we investigated whether differences in time dependent changes in blood amino acid concentrations affected acute blood glucose and urea responses, and recovery of muscle function after a bout of strength training. Methods: Ten young healthy, recreationally active men ingested different milk protein supplements after a whole-body strength training session on five occasions in a randomized manner. Blood concentrations of amino acids, glucose and urea was measured before and 0, 30, 45, 60, 90, 120 min, and 22 and 30 h post-exercise. Maximal voluntary isometric knee extension and counter movement jump were assessed before, immediately after, 6, 22 and 30 h after exercise.