I am aware that Surge contains BCAAs, and I use it post-workout; it would be great if Biotest offered a pre-workout BCAA formula of proportionally affordable price and a similarly high quality.
Try Power Drive.
http://www.t-nation.com/readTopic.do;jsessionid=7F9D1EB00401180193BD91136A3B9DD3.titan?id=459249
Also, you can drink Surge before, during or after your workout or any combination there of. There is no strict rule that says only post-workout.