i hurt my back a few months ago and was layed up for a month and a half, i was piss weak when i came back, its now 8 weeks later and i am now back to my best. 3 board sessions a week and a few max hangs on rest days has been my routine, seemed to work well. I would have thought you could achieve reasonable gains in 6 weeks, i find it never takes to long to get back to strength, its getting past it that takes the time.