Basically what your doing with the introduction of milk with your whey protein is making it act like Casein protein with a slower breakdown.
I’m 46 and the second I step off the trainer I grab one of my mixers and get to shaking up 2 scoops of cheap GNC Gold Cookies and cream and 1/2 scoop of powdered peanut butter with 20 oz of milk. I dont have any issues with Delayed Onset Muscle Soreness (DOMS) and feel that I’m recovering well after each workout.