I did this all the time expect that I was about 20-25 feet away. I had better control and could put the ball where I wanted it. In a cage, I would move the plate approx. 50' from the back of the net. This way collecting the balls was faster. Front toss trains the batter better than anything. This is why major leaguers still do it at batting practice. During nationals one year, I estimated that I threw over 5000 pitches in a 6 day period.
5000..... just think about that for a moment man, you most likely threw near 1000 and even then you're arm would be completely dead. You would have aches all in your arm from that much and it wouldn't go away for a week.