Whey after exercise, but.....
you must make sure your diet is spot on too. Lots of fresh, low GI fruits and vegetables, lean proteins - eggs, poultry, fish, red meat, pulses.
Remember, they are protein SUPPLEMENTS - they supplement a good diet, do not replace it.
Sorry you should take a Whey protein concentrate not Isolate! and take it only
between 20-30 minutes after your work out.