specifically help in your sport? test is well known to be the worst for boxing... its better for mma as the same repititous movement isnt done over and over...it causes water weight gain, causes muscles to get sore faster, stays in your system long time periods, hurts endurance, and just to mention this...could get you to lose your pro card alltogether...
I have trained, cornered, and helped prep a few pro mma fighters and MT kickboxers....the weight classes in boxing are SOOOO tight that any significant weight gained from AAS will DEF push you out of your weight class, if not 2 or 3 higher...which i would again see as a negative effect..
I also know of 3 or 4 pro fighters...1 of which is rated one of the top 5 in the world in his class .....that take either anavar and halo at different points in their prep...
IMO...the only times a fighter would ever need AAS would be for weight cut at fight time if a TRUCKLOAD of money was on the line and they knew they would b struggling to make the weight...and then i would say that he/she probably wasnt prepped rite anyways...
The TOP professionals in the sport of boxing DONT use it.... in MMA its usage is a lil higher...