Rule of thumb.Whey protein Isolates right after training
The only draw back to Whey Protein Isolates is they digest very fast, so they have a very fast absorption rate.
So with Whey Protein Isolates you cant take as much protein at a time, like you would a combination protein ( Milk, Egg, Whey)
During the day and at night its good to have atleast a 3 stage protein, because if your eating every 2-3 hours you want your body to remain anabolic in between meals.So make sure your using a protein with Milk Isolate, Miscellar casein, Whey Protein concentrates, and Whey Protein Isolates.
At night time before bed, make sure that your protein contains Egg Albumen ,Milk concentrates,Calcium Caseinates,Miscellar Caseins, Whey Protein Isolate,Whey Protein Concentrates, then add 10 grams of L-Glutamine, and 5 grams of BCAAS.
This way your body will have all the amino acids it needs to repair itself while you rest
Remember Casein Proteins have a slower digestion rate, to fuel your muscles longer