I workout at night after dinner. I usually am in bed about an hour after my w/o. I drink a post w/o drink right after my w/o (I w/o at home so it is pretty much within 10 min.). Then just befor I hit the sack, I eat a small meal. I have gained both muscle and strength. Is it the most efficient time, I do not know from a muscle gain/growth standpoint. It has been argured that you should w/o earlier in the day. But for me it is just a preference, it is a way to top off a good day with a good w/o. Seems to work for me.