Players using the ball machine will tell you they get a great workout and it helps their stroke production, timing, and ball placement. The ball machine can wear you out, though, by sending ball feeds too quickly (interval), too fast (mph), too deep/high. When using the machine, adjust the ball feed to mimic what you normally get, such as heavy slice, topspin, low and high balls, etc., and simply pace yourself. Do not hit so long that you get tired and sloppy. This is when your form will break down. Practice good form and technique from start to finish on the court, and remember, if you blow it, blow it looking good!